Living
With a Star TR&T Program
Abstracts of awarded Proposals
NNH05ZDA001N
March 2006
PI:
Rashid Akmaev/University of Colorado
Title: A Data Analysis and Modeling Study of Secular Change in Thermospheric
Density
Abstract:
We propose a data analysis and modeling study of long-term changes that have
occurred in the upper atmosphere over the recent several decades. Interest in
these trends has been stimulated by the classical modeling study of Roble and
Dickinson (1989), who predicted a dramatic response to a hypothetical future
increase of greenhouse gases: the upper atmosphere is expected to cool down
by tens of degrees in response to the standard doubled-CO2 scenario. The search
for signs of global change in upper-atmospheric and ionospheric historical data
records has been inconclusive. While some parameters clearly reveal long-term
trends in general agreement with the model predictions, other estimates have
produced inconsistent and even contradictory results due, in part, to the scarcity
of sufficiently long uniform observational records. Our ability to detect trends
is also confounded by the enormous variability of the upper atmosphere driven
primarily by solar and geomagnetic activity on various temporal and spatial
scales. The ''greenhouse cooling'' is expected to result in a substantial thermospheric
density decline that depends on the level of solar activity. Existing analyses
of neutral density trends based on satellite drag data over the last 2 to 3
decades have provided perhaps the most robust evidence of global change in the
upper atmosphere to date. These results inherently provide a global view and
qualitatively agree with each other and with theoretical model predictions.
More work is required to improve our confidence in the trend estimates, to delineate
the contributions of solar activity and other parameters, to better understand
the physical mechanisms, and to quantify their contributions to the observed
changes. The science goal of this project is to advance our understanding of
the mechanisms driving the long-term global changes in the upper atmosphere
and the near-Earth space environment. Our approach is unique in that it synergistically
combines two key components: (1) we will extend, in time and altitude coverage
and in number of observations per year, our comprehensive analysis of the global
satellite-drag database to delineate the contributions of solar activity and
other sources of natural variation, and to detect anthropogenic and possible
natural long-term trends; (2) we will use an updated global upper-atmospheric
numerical model to study the natural and anthropogenic variability using the
records of greenhouse gas concentrations and solar activity over the same period
of time. A direct comparison of the results of theoretical modeling with the
analysis of accurately determined trends in the upper atmosphere will be carried
out for the first time. This will provide insights into the key physical mechanisms
and their possible interactions and feedbacks, and will facilitate the attribution
of the observed trends. A clearer understanding of the thermospheric ''greenhouse
cooling'' will lead to development of meaningful long-term forecasting capabilities.
This work is immediately relevant to the science goals of the NASA Living With
a Star program and, in particular, to its Targeted Research science topic T3e.
The ability to understand and predict the long-term density variability in the
near-Earth space environment is also of enormous practical significance to any
spacecraft operators, including the NASA's programs and missions.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Amitava Bhattacharjee/University of New Hampshire
Title: Heating the Corona and the Solar Wind by Magnetic Reconnection
Abstract:
Understanding the heating of the corona and the solar wind is a primary objective
of the LWS TR&T program. We propose to investigate the role of magnetic
reconnection as a fundamental heating mechanism of the global corona and the
solar wind. Magnetic reconnection and solar wind acceleration and heating are
identified, respectively, as Research Focus Area F1 and F2.3 in the most recent
Sun-Solar System Connection Roadmap (May, 2005). Both of these areas are objectives
of several ongoing and future missions including SOHO, TRACE, RHESSI, RAM, Solar
Probe, SDO, Solar-B, Solar Orbiter, SPI, STEREO and Doppler. The heating of
the solar corona and the solar wind occurs continually, in regions of closed
as well as open field lines (coronal holes), in the quiet as well as the active
Sun. The magnetic carpet, which covers the entire surface of the Sun, holds
the key to our understanding of this heating. It is estimated that 95% of the
photospheric magnetic flux closes within the magnetic carpet in low-lying loops.
There is significant observational evidence that strong coronal heating in active
regions have much in common with the quasi-steady heating in quiet regions and
coronal holes, and that the latter may occur due to scaled-down versions of
explosive reconnection events in bipolar configurations in the network. We propose
to use analytical techniques and time-dependent simulations based on resistive
and Hall MHD equations to investigate the role of collisional as well as collisionless
current sheets and reconnection in heating the corona and the solar wind. We
will undertake the following tasks: (1) Coronal Heating Driven by Explosive
Reconnection in Sheared Network Bipoles. We will begin with a simple 2.5D bipole
configuration in which reconnection is driven by photospheric footpoint shear,
and investigate current sheet formation and magnetic reconnection in resistive
and Hall MHD regimes. We will follow up with configurations of increasing complexity
leading up to the tectonics model which includes a myriad of bipoles with multiple
separatrices, and quantify the amount of heating as a function of the dissipation
mechanism. (2) Reconnection and Thin Current Sheets in 3D Line-Tied Geometries
With and Without Nulls. We will consider 3D magnetic geometries of line-tied
fields, both with and without nulls, and quantify their contributions to coronal
heating. We will build on our recent rigorous results on the Parker model of
tangential discontinuities, which is a prime example of a model without nulls,
and explore connections with quasi-separatrix layer (QSL) models. We will also
consider the build-up of current sheets and fast reconnection in models with
nulls and null-null lines by a combination of exact analytical models and 3D
simulations. (3) Generation of Alfvén Waves by Photospheric Reconnection.
We will investigate the possibility of generating Alfvén waves in regions
containing open field lines by photospheric reconnection in low-lying loops.
In turn, these waves can produce producing an enhanced flow of wave energy into
the solar wind. With this quantitative analysis, we will determine whether the
energy flux in these waves is sufficient to explain the observed long-period
power and can drive heating and solar wind acceleration in coronal holes. (4)
Energetics, Scaling Laws for Heating, and Observational Tests. We will attempt
to answer the following questions: What fraction of the magnetic free energy
in a given network configuration is dissipated as heat by resistive and collisionless
reconnection mechanisms? How does the heating scale as a function of the plasma
parameters and system size? What are the corresponding scaling properties for
Alfvén wave heating produced by photospheric reconnection? Are nanoflares
and microflares, reflected in EUV emission, sufficient to account for coronal
heating in regions of closed as well as open field lines?
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Dieter Bilitza/Raytheon Technical Services Company
Title: TOPLA: A New Empirical Representation of the F-region Topside and Plasmasphere
for the International Reference Ionosphere
Abstract:
We propose to develop a new data-based F-region TOpside and PLAsmasphere (TOPLA)
model for the electron density (Ne) and temperature (Te) for inclusion in the
International Reference Ionosphere (IRI) model using newly available satellite
data and models for these regions. IRI is widely used for the specification
of ionospheric conditions and is currently under consideration as the International
Standardization Organization (ISO) standard for ionospheric parameters. IRI¿s
great significance for LWS science lies in its role as the observation-based
background ionosphere for theoretical coupling studies between different regions,
for radio wave propagation studies, for the evaluation of tomographic and numerical
techniques (GPS), and as benchmark against which the skill-level of physics-based
forecast models is measured. Additionally, IRI helps to teach and popularize
space science through its usage for college course work and for web interfaces
that visualize and explain the space environment. Recently, a number of new
data sets have become available that help to fill coverage gaps of earlier studies
and that can provide the database for a systematic improvement of the IRI topside
model. Specifically our study will overcome the following shortcomings of the
current IRI topside model: (1) overestimation of densities above 700 km by a
factor of 2 and more, (3) unrealistically steep density profiles at high latitudes
during very high solar activities, (4) no solar cycle variations and no semi-annual
variations for the electron temperature, (5) discontinuities or unphysical gradients
when merging with plasmaspheric models. Our topside Ne model will be based on
Alouette 1, 2, and ISIS 1, 2 topside sounder data and will use a Chapman-function
with a height-varying scale-height H(h) that allows merging the topside profile
with the plasmasphere model. The Ne model for the plasmasphere will rely on
IMAGE/RPI data and will be based on combining and further developing the modeling
approaches introduced by CoIs Reinisch and Huang based on IMAGE data and by
CoI Gallagher based on DE and ISEE data. For the electron temperature the goal
is to develop the first empirical model that fully accounts for solar cycle
variations based on a large volume of satellite in situ measurements. A special
focus will be the correct representation of (a) altitudinal and latitudinal
extent of the Equator Anomaly region, (b) latitudinal, diurnal, and seasonal
differences in the solar cycle variation of temperatures and densities, and
(c) diurnal, latitudinal, and solar and magnetic activity variations of the
topside transition height. Results of this study will provide substantial improvements
in characterizing the ionosphere/ plasmasphere environment in support of manned
and unmanned space exploration. The enhanced IRI model will provide a key baseline
for studying geomagnetic storm effects on the ionosphere and plasmasphere.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Joseph Borovsky/Los Alamos National Laboratory
Title: Predicting the Spacecraft-Charging Environment in the Magnetosphere from
Upstream Solar-Wind Parameters
Abstract:
A three-year project is proposed to determine how the solar-wind plasma drives
the spacecraft-charging environment inside the Earth's magnetosphere. The project
builds on a series of recent studies that have determined the correlations and
time lags between the properties of the solar-wind plasma and the hot-ion plasmas
of the magnetosphere. The present study will focus on the connection between
the solar wind and (a) the hot-electron plasma, (b) the low-density cold-ion
population, and (c) measured values of spacecraft potentials, all in the magnetosphere.
The study will utilize approximately 20 million measurements of spacecraft charging
and the charging environment taken around the Earth's dipole at geosynchronous
orbit. The objectives of this project are (1) to establish which solar-wind
parameters affect the charging environment in the magnetosphere and by how much,
(2) to determine the time lags at various locations around geosynchronous orbit
for the solar wind to affect the environment there, (3) to determine the functional
forms of the best-fit expressions connecting solar wind parameters with magnetospheric-environment
parameters, (4) to determine how substorms affect the coupling and time lags
of the solar wind to the charging environment, (5) to determine whether dipole
inflation by a stormtime ring current affects the coupling and time lags of
the solar wind to the charging environment, and (6) to assess the ability of
the best-fit expressions and time lags to predict the charging environment from
solar-wind input. The data sets that will be used are uniquely suited to this
project and techniques that have been successful in similar studies will be
utilized. The primary data set resides at Los Alamos and the Investigators have
sufficient expertise to perform the tasks and interpret the results. In support
of NASA and the LWS Program, this project will greatly further the understanding
of the origin and control of the spacecraft-charging environment and will provide
the information needed to predict that environment with a few-hour lead time.
The project will also significantly further our understanding of the entry and
transport of plasmas in the Earth's magnetosphere.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Athanasios Boudouridis/University of California, Los Angeles
Title: Solar Wind Geoeffectiveness as a Function of IMF and Dynamic Pressure
and its Effect on High-Latitude Ionospheric Energy Deposition
Abstract:
The electric field and particle precipitation patterns at high latitudes are
two of the most significant considerations for determining the ionospheric state
during steady or variable solar wind and Interplanetary Magnetic Field (IMF)
conditions. It is therefore of primary importance to fully understand what drives
the electric fields and particle precipitation at high latitudes. It is well
known that the IMF is the major contributor to geomagnetic activity on Earth.
Recent studies, however, have shown that solar wind dynamic pressure variations
cause global effects when they encounter the terrestrial magnetosphere, strongly
affecting the magnetosphere, ionosphere, and upper atmosphere. In particular,
it has been shown that solar wind dynamic pressure enhancements significantly
increase particle precipitation and cause global intensification of the aurora,
thus significantly increasing the deposition of energy in the Earth's upper
atmosphere. In addition, the extent of the enhanced energy deposition is dependent
on the preexisting state of the magnetosphere, which is controlled by the IMF
orientation. Further studies have demonstrated that solar wind pressure increases
also affect the cross-polar-cap potential drop (CPCP), and thus the coupling
efficiency between the solar wind and the Earth's magnetosphere in ways that
cannot be accounted for solely by the existing solar wind electric field. It
is rather the combined contribution of IMF and dynamic pressure, in ways that
are yet to be determined, that controls the coupling efficiency between the
solar wind and the magnetosphere. Therefore, the pressure enhancements and IMF
variations affect both the solar wind geoeffectiveness and the energy input
in the high-latitude ionosphere and upper atmosphere. We propose to study the
relative contribution of solar wind dynamic pressure, IMF Bz, and IMF By to
solar wind geoeffectiveness during steady and variable conditions, and investigate
under which circumstances the correlation between solar wind geoeffectiveness
and high-latitude energy deposition is the highest. For this purpose we will
utilize a combination of solar wind measurements, low-altitude Defense Meteorological
Satellite Program (DMSP) data, and results of the Assimilative Mapping of Ionospheric
Electrodynamics (AMIE) technique. We will focus our research on the following
scientific questions: 1) What is the effect of different IMF orientations and
solar wind dynamic pressure levels on the solar wind-magnetosphere coupling
efficiency under steady conditions? 2) How do variations of dynamic pressure
and IMF modify the CPCP and the coupling efficiency? 3) How permanent or transient
are these responses for step-like changes in the solar wind, and what are the
relevant timescales? 4) What is the relative contribution of dynamic pressure
and IMF orientation to the CPCP and solar wind geoeffectiveness under steady
or changing conditions? 5) How do IMF orientation, dynamic pressure levels,
and their changes affect high-latitude energy deposition as measured by the
intensity of precipitating flux or ionospheric Joule heating?
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Pontus Brandt/The Johns Hopkins University Applied Physics Laboratory
Title: Storm-Time Sub-Auroral Electric Fields: Ionospheric and Magnetospheric
Control
Abstract:
The role of electric fields in the sub-auroral ionosphere have been underestimated
for a long time largely due to the lack of understanding of their origin and
global behavior. Solar irradiation, Joule heating and the ring current cause
ionospheric electric fields. Separation of their different origins is inherently
difficult due to limited spatial coverage of measurements (radars, low-latitude
satellites). We propose to provide a realistic model of the sub-auroral electric
field, produced by the ionospheric closure of the ring current, using observations
and modeling, and investigate how it is controlled by magnetospheric activity
and ionospheric conductance. The output electric fields is intended to be used
as input by other thermospheric models investigating the transport and density
of the ionosphere/thermosphere. Our work can be divided into the following tasks.
TASK I - Perform a correlative statistical study of ionospheric electric fields.
Three types of electric fields will be investigated: (1) Penetration (or undershielding)
electric fields; (2) Sub-auroral Polarization Streams (SAPS); (3) Midnight-dawnside,
sub-auroral flow reversals. Observational parameters will include solar wind
conditions, ionospheric conductance, Region-2 current intensity. TAKS II - The
sub-auroral, ionospheric electric field of selected storm events will be modeled
using the Comprehensive Ring Current Model (CRCM), which computes the electric
field, self-consistently arising from the closure of the ring current through
the ionosphere. TAKS III - The results from the observational and model study
will be combined into a climatological model of the behavior of the sub-auroral,
ionospheric electric fields. The most outstanding ionospheric effect is the
uplift of plasma through penetration electric fields on the low-latitude dayside,
causing storm enhanced densities (SED) in the F-layer. The SEDs corotate into
the duskside ionosphere where ring-current driven electric fields transport
plasma to mid-latitudes and sunward. The SEDs have far reaching consequenses
for a number of technological systems over our heavily populated continent.
For example, the Wide Area Augmentation System (WAAS) assists positioning of
civil aircraft by providing time delay of Global Positioning System (GPS) signals
from geosynchronous satellites. However, WAAS can only provide time delays from
about a two dozen of stations over the North American continent, forcing aircraft
to interpolate the time delay value between stations. At disturbed times, the
ionosphere display very high densities in very confined regions which makes
the position determination by interpolation invalid. The proposed work fulfills
the NASA National Objective: ``Study the Earth system from space and develop
new space-based and related capabilities for this purpose.'' and all of its
sub-objectives. As recommended by the LWS TR\&T Science Definition Team,
the proposed work relies on large-scale modeling work that addresses the coupling
between the two traditional domains of the storm-time magnetosphere and ionosphere
and offers to provide its output (large-scale, sub-auroral electric fields driven
by the magnetosphere) to be used further by thermospheric models. We therefore
believe that the proposed work will be a useful strategic capability in understanding
the storm-effects on the global electrodynamics and the mid- and low latitude
ionosphere/thermosphere system.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Robert Cahalan/NASA Goddard Space Flight Center
Title: Wavelength and Time Dependence of Solar Forcing of Earth's Atmosphere-Ocean
System
Abstract:
The Sun's radiative input to Earth has characteristic temporal variations that
depend on wavelength, as we have documented under previous funding. We propose
to further analyze SIM (Spectral Irradiance Monitor) solar spectral irradiance
(SSI) data, and compare with SSI synthesized from the SRPM model (Solar Radiation
Physical Modeling), to estimate the statistical relations between SSI and total
solar irradiance (TSI), to study the responses of atmosphere-ocean mixed layer
to variations in solar spectral irradiance. Proposed research will include the
analysis of existing solar spectral irradiances from SORCE SIM, with coincident
ground-based and aircraft observations from the Solar Spectral Flux Radiometer
(SSFR) to estimate spectral solar forcing in the troposphere and stratosphere,
and to model the atmospheric response to variations in SSI, to advance our understanding
of the wavelength and time dependence of solar forcing of Earth's atmosphere-ocean
system. This proposal falls into the category of Independent Investigations,
and has three tasks: (1) Variations in Spectral Solar Irradiance (SSI): Extend
the analysis of SSI from SIM on SORCE to the fully calibrated time series and
compare with synthesized solar spectrum from the SRPM model (Solar Radiation
Physics Modeling). Estimate the statistical relations between of SSI and TSI.
(2) Spectral Solar Forcing: Estimate the vertical profiles of spectral and total
solar forcing by analyzing the existing SORCE SSI, with coincident ground-based
and aircraft observations from the Solar Spectral Flux Radiometer (SSFR). (3)
Modeling the response of the atmospheric and surface temperature to the variations
of SSI: A simple radiative-convective model (RCM) will be used to study atmospheric
and surface responses to variations in SSI. The 1-D RCM will be extended to
account for time-dependence of both variation of SSI and response of atmosphere-ocean
mixed layer.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Margaret Chen/Aerospace Corporation
Title: Solar-Wind Ion Entry into the Magnetosphere through the Magnetosheath
Abstract:
This is a proposal to investigate the physical processes that lead to the transport
of solar wind ions from the magnetosheath and into the magnetosphere to form
the plasma sheet. Ion distributions in the magnetosheath, tail lobes, tail flanks,
and plasma sheet will thus be characterized for different Interplanetary Magnetic
Field (IMF) and solar wind conditions. The study will address whether the transport
of solar wind ions into the magnetosphere from different locations supply sufficient
particles of different energies needed to form the quiescent and storm-time
plasma sheet. The effect of changes in the solar wind population on the variance
in the plasma sheet will also be examined. Our approach will be to develop and
use kinetic simulations to study the relevant particle transport processes and
to compare our simulation results with published observations such as from Geotail,
ISEE, AMPTE, and DMSP. We will follow the full particle motion or (where appropriate)
the guiding-center drifts of solar-wind ions from the magnetosheath into the
magnetosphere. In the magnetosheath, we will use an analytical magnetic field
model that reproduces quite well the shape of magnetosheath field lines obtained
from gas-dynamic calculations. The magnetosheath electric field is proportional
to the cross product of the solar-wind velocity and the magnetic field. Especially
for southward IMF, the magnetosheath's magnetic field lines will reconnect with
initially closed magnetospheric field lines. For the magnetospheric model, we
will use the magnetically and electrically self-consistent Rice Convection Model
(RCM-E) with a magnetic field boundary condition that includes the effect of
a non-uniform penetration magnetic field. This magnetospheric model maintains
internal force balance between the magnetospheric plasma and magnetic field.
Use of the RCM-E will allow us to calculate self-consistent distributions of
particle flux, plasma pressure, and current density within the magnetosphere
(including the tail flanks and plasma sheet). We will study how these distributions
evolve as we vary the solar-wind conditions, and we will compare the simulated
results with observations. A significant outcome of this work will be a physical
understanding of the relationship between properties of the solar-wind plasma
(e.g., velocity and density) and the resulting plasma sheet, which is the main
source for the ring current. This would provide a currently missing link for
characterizing magnetic storms (and eventually accounting for variations of
particle population in the inner magnetosphere) from solar-wind properties and
IMF conditions. Such an achievement would be beneficial for understanding and
forecasting space weather, and thus for society.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Christina Cohen/California Institute of Technology
Title: Understanding Energetic Particle Responses to Local Interplanetary Shocks
through Observations and Theory
Abstract:
We propose to study the energetic particle increases associated with the passages
of interplanetary shocks. Although such events, called energetic storm particle
(ESP) events, have been studied since the 1960s and theories of particle acceleration
by traveling shocks are well developed, previous surveys have repeatedly shown
that the many of predicted relationships between the shock parameters and the
ESP characteristics are not apparent in the spacecraft data. Exploring these
discrepancies, identifying new relationships, and determining relationships
that do hold (based on theoretical models) is crucial in the quest to fully
understand shock acceleration as it is manifested in the interplanetary medium
and to predict the particle response to shocks moving outward from the Sun towards
Earth. The solar energetic particle (SEP) events created by shocks driven by
coronal mass ejections (CMEs) are a concern for space operations and we are
far from being able to predict them. Fortunately, most SEP events are limited
in intensity by the streaming limit imposed by the magnetic turbulence generated
by the energetic protons. However, in the vicinity of a shock, this limit is
typically exceeded by the ESP event, resulting in intensity increases that can
be orders of magnitude in size and a significant space weather threat. Additionally,
ESP events are our only opportunity to examine the particles accelerated by
CME-driven shocks in situ where both the shock and particle parameters can be
measured and correlated. More sensitive particle measurements are being made
than ever before and by combining the data from the ULEIS and SIS instruments
on ACE the energy spectra of heavy ions can be determined over more than 3 orders
of magnitude in energy. Spectra of protons and helium are also available from
the EPAM instrument and at higher energies from ULEIS and SIS and, when appropriate,
GOES. Recently, analysis of interplanetary shocks observed by ACE and Wind has
been expanded to routinely fit the plasma and magnetic field data with a variety
of methods resulting in a more accurate determination of shock parameters. We
propose to combine these improvements in particle measurements and shock analysis
with theoretical expertise in shock acceleration to understand the physical
reasons for the lack of correlations previously reported for shock parameters
and ESP characteristics and to enable progress in constructing a predictive
capability.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Pallamraju Duggirala/Boston University
Title: Daytime Multiwavelength Ground-Based Optical Investigations of Precursors
to Low-Latitude Plasma Irregularities
Abstract:
We propose a 3-year project to carry out systematic investigations of the precursors
to the ESF irregularities during daytime using a ground-based optical multiwavelength
Echelle spectrograph to be built at BU. Equatorial Spread-F (ESF) refers to
the presence of plasma irregularities at low- and equatorial latitudes in the
nighttime ionosphere. Unlike substorms and geomagnetic storms, ESF is a form
of space weather not controlled exclusively by the Interplanetary Magnetic Field
(IMF). ESF irregularities severely impact radio communications and navigational
systems at a wide range of frequencies that adversely affect commercial and
defense applications. The development of these irregularities is highly unpredictable.
Even during the ¿ESF season¿ when various onset parameters are
nearly identical, ESF occurs on one night and is completely absent on the other.
Scientifically, this is a key-missing element in our understanding of plasma
instabilities at low latitudes. This proposed work will carry out daytime optical
measurements to investigate the roles of neutral parameters, such as the meridional
and vertical winds and waves that are known to be effective triggers to the
ESF. For the first time in history, we will have a large field-of-view multiwavelength
spectrograph that is most suited to answer these relevant issues. We will carry
out daytime measurements using three emissions 5577, 6300 and 7774 Å,
which originate around 100, 230 and 300 km, respectively. These large field-of-view
measurements will enable us to investigate waves and their direction of propagation
at three different altitudes. The results from this study will not only resolve
issues surrounding the precursors to ESF but will substantially enhance our
understanding of the interaction of daytime and nighttime phenomena of the low-latitude/
equatorial electrodynamics in upper atmosphere. We plan to operate the new instrument
at Carmen Alto (23.1^o S, 70.6^o W; 10.2^o S dip lat.), in Chile. This data
will be used in conjunction with the multi-diagnostics of the Multi-Instrumented
Studies of Equatorial Thermosphere Aeronomy (MISETA) consortium operating in
the American longitude sector as well as Thermosphere Ionosphere Mesosphere
Energetics and Dynamics (TIMED) satellite and Communicational/Navigational Outage
Forecast System (C/NOFS) mission (scheduled to be launched in 1996). Furthermore,
Jicamarca Unattended Long-term Investigations Atmosphere (JULIA) radar data,
Jicamarca Radio Observatory (JRO) data, Global Positioning Systems (GPS) and
Defense Meteorological Satellite Program (DMSP) data will be available for independent
confirmation of the occurrence of ESF irregularities and for the information
on the background thermosphere/ionosphere conditions in conjunction with our
ground-based data. This dayglow data at multiple wavelengths will add to the
rich database and a unique resource to the community.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
David Facloner/NASA Marshall Space Flight Center
Title: Development of Empirical Tools for Forecasting Safe or Dangerous Space
Weather from Magnetograms
Abstract:
The overall objective is to further develop and evaluate empirical tools for
forecasting from magnetograms whether an active region will or will not produce
a coronal mass ejection (CME) in the next few days, and, as a byproduct, gain
insight to the magnetic conditions that cause CMEs. The proposed investigation
builds directly on results that we obtained with previous LWS TR&T funding.
In particular, we found an empirical measure of whole-active-region nonpotentiality
that can be measured from a line-of-sight magnetogram of the active region and
is strongly correlated with the CME productivity of active regions. This allows
us in the proposed work to (1) use the MDI full-disk line-of-sight magnetograms
to obtain large sets of separate-day magnetograms (~200) of active regions,
and (2) use the good sensitivity of these magnetograms to assess, for spotless
active regions as well as for sunspot active regions, the accuracy of the nonpotentiality
measure as a predictor of All Clear space weather (no strong CMEs) or dangerous
space weather (strong CMEs likely). In addition, using the ~200 magnetograms
of sunspot active regions, we will carry out a bivariate analysis of the dependence
of CME productivity on the nonpotentiality and size of active regions. The results
will contribute directly to the development of operational CME forecasting methods
that can be applied to and further developed and tested by the active-region
vector magnetograms from Solar-B and the full-disk vector magnetograms from
SDO. Our results, in combination with other observations from SOHO, Solar-B,
and SDO, will yield better understanding of the magnetic conditions that cause
CME explosions. Thus, in addition, to advancing the LWS TR&T goal of developing
empirical tools for CME forecasting, the proposed investigation will enhance
the science payoff from SOHO, Solar-B, and SDO. The requested funding is for
half-time support of the PI and half-time support of a graduate student research
assistant.
Living With a Star TR&T Program
NNH05ZDA001N
PI:
Bela Fejer/Utah Sate University
Title: Storm-Time Ionospheric Electric Fields
Abstract:
We propose to use a very extensive database of plasma drift observations made
on-board the Republic of China satellite (ROCSAT-1), Dynamics Explorer (DE-2),
and Atmosphere Explorers E and C (AE-E and AE-C) satellites, as well as detailed
ground-based magnetic field observations to study the storm-time, latitude-,
and longitude-dependent response of mid- and low-latitude ionospheric electric
fields to solar wind and magnetospheric disturbances. We plan to complement
our experimental studies with numerical simulations using recent and future
upgraded versions of the Rice Convection Model (RCM). The first basic objective
of this proposal is to use this extensive combined satellite database of perturbation
electric fields (obtained by removing quiet-time values along satellite orbits)
to develop a detailed understanding of the local and storm-time, season, solar
cycle dependent response of prompt penetration electric fields (mostly at low
latitudes) to various solar wind-magnetosphere-ionosphere driving processes
for different storm and solar cycle phases and seasons. These driving processes
include the interplanetary electric field, IMF clock angle, and solar wind dynamic
pressure. The second objective is the study of the longitudinal and latitudinal
variations of the prompt penetration and disturbance dynamo electric fields
under different geophysical storm conditions. This includes the study of the
longitude-dependent relationship of low-latitude prompt penetration electric
fields and subauroral polarization streams (SAPS). The third objective is the
use of our experimental results for detailed testing of longitude-dependent
predictions from global convection models, particularly during large magnetic
storms. These studies should significantly improve the understanding of global
characteristics of storm-time ionospheric electric fields and made a major contribution
to future NASA missions, particularly to multi-spacecraft ionospheric missions.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
John Foster/MIT Haystack Observatory
Title: Multi-Instrument Investigation of Inner-Magnetosphere/Ionosphere Disturbances
Abstract:
Strong penetrating and SAPS electric fields perturb and redistribute the cold
plasma of the low and mid-latitude ionosphere and plasmasphere during geomagnetic
disturbances. The phenomena associated with plasmasphere erosion are a prime
example of global M-I coupling and require a multi-technique and multi-disciplinary
analysis approach to understand properly. Streaming cold plasma, as seen as
storm enhanced density SED plumes, can be used to identify and trace the effects
of the perturbation electric fields. At lower latitudes, plasma redistribution
and prompt changes in TEC indicate the effects of the disturbance electric fields.
A thorough understanding of the mechanisms, causes and effects of these disturbance
electric fields are needed to support a predictive capability for these important
ionospheric phenomena. Questions to address: 1) Does the SAPS E field exhibit
seasonal or longitude dependencies? 2) What determines the duration and strength
of penetration electric field? 4) How do the conjugate E and F-region conductivities
influence SAPS formation? 4) How does wave structure in the SAPS/SED channel
lead to ionospheric irregularities? 5) What are the causes and characteristics
of the redistribution of the equatorial ionosphere in the American sector? Proposed
Method: 1) Use ionospheric TEC observations to study the location, extent, and
duration of perturbation electric fields at mid and low latitudes. 2) Combine
space and ground-based (GPS) TEC observations, incoherent-scatter radar (ISR)
profiles, and DMSP observations to characterize the conditions leading to severe
low-latitude ionospheric perturbation. 3) Investigate the relationship of the
plasma redistribution to ionospheric irregularities using coherent radar, HF
radio scintillation, and passive radar arrays (ISIS). 4) Coordinated ISR experiments
(Sondrestrom, Millstone Hill, Arecibo, and Jicamarca) will investigate penetration
E fields. 4) Modeling collaboration (RCM and SAMI-II) to address the relationship
of the observed features and their evolution to the predicted effects of ring
current development and inner magnetospheric shielding. 6) Develop a multi-technique
viewpoint of the coupled processes through workshops held at Haystack. 7) Coordinate
a distributed working group to investigate storm phenomena using Access Grid
and similar remote conferencing techniques. 8) TEC maps and merged datasets
made available through the online Madrigal data system. This research program
follows upon the considerable research that the PI institution has already undertaken
on problems in this focused research area. The PI institution has organized
a CEDAR working group on low-latitude electric field, and has designed and fielded
instrumentation arrays (ISIS) to address electric-field structure, with continuous,
spatially-distributed observations.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Tim Fuller-Rowell/University of Colorado
Title: Modeling the Impact of Storm-time Electrodynamics on the Mid and Low
Latitude Ionosphere
Abstract:
Project Summary: The goal of this research is to determine the circumstances
leading to the massive restructuring of the mid and low latitude ionosphere
and the development of large-scale bite-outs of electron density at low latitudes
during geomagnetic storms. Good examples of these features occurred during the
Halloween storm in October 2003. Maps of total electron content (TEC) showed
a factor of four increase at mid latitudes, and measurements of electron density
by the DMSP satellite at 850 km indicated the ionosphere had virtually disappeared
over a wide latitude swath at low latitudes. The depleted region, or ¿bite-out,¿
was accompanied by smaller scale ionospheric irregularities, or bubbles, on
its flanks. It is expected that the dramatic plasma gradients were created by
exceptionally large upward ExB plasma drifts, raising the ionosphere to higher
altitudes, transporting plasma poleward, and driving the huge depletions at
low latitude. This study will investigate the interaction and feedback between
the two main sources of the plasma drift ¿ the prompt penetration (PP)
and disturbance dynamo (DD) electric fields, and determine the cause of the
massive restructuring of plasma at mid and low latitudes during storms. This
project is a ¿linked¿ proposal between research teams at University
of Colorado (PI Tim Fuller-Rowell) and Rice University (PI Stan Sazykin). The
success of the project relies on the self-consistent coupling between physical
processes in the thermosphere, ionosphere, and plasmasphere (as captured in
the CTIPe model) and the inner magnetosphere (as captured in the RCM). Combining
these two models includes both dynamo and penetration electrodynamics, and consistently
handle the feedback between the two regimes. This study is therefore unique
in its ability to couple the various domains and address the science questions
in a rigorous mathematical approach. This study will: 1) Determine the physical
processes leading to the large vertical plasma drifts and the interaction and
feedback between the penetration and dynamo electric fields, 2. Determine the
impact on the mid and low latitude ionosphere including the cause of the massive
restructuring of plasma density, and 3) Investigate the possible causes of the
strong longitude dependence in the storm-time response. The first phase of the
study will perform the comprehensive coupling of the CTIPe and RCM models where
the polar cap boundary, the neutral wind driven dynamo currents, and the field-aligned
magnetospheric currents are consistent between the two codes. The effects of
under and over shielding in the inner magnetosphere will be implicitly included
in the field-aligned currents and the potential solver. Numerical experiment
will be performed with a goal of understanding the complex interaction between
the geophysical domains including the electrodynamic feedback between PP and
DD. For validation, the coupled model will be used to simulate the recent storms
targeted by the recent CDAW workshop. The chosen storms have good global and
regional coverage for TEC, have reasonable measurement of the electric fields,
and have well developed experimental/observational databases. The potential
benefit of this study for space weather is clear. Large-scale changes in the
ionosphere impact GPS navigation signals and alter the propagation of HF radio-wave
communication. The large-scale ionospheric changes are also associated with
the generation of small-scale ionospheric irregularities responsible for scintillations
on satellite communication signals. Understanding the physical processes will
lead to the possibility of improvement in predicting and forecasting the storm-time
plasma redistribution and the creation of irregularities. This proposal targets
the specific research topic of the LWS TR&T Focused Science Topic ¿Storm
effects on the electrodynamics and the middle and low latitude ionosphere¿.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Natchimuthuk Gopalswamy/NASA Goddard Space Flight Center
Title: Coordinated Data Analysis Workshops (CDAWs): Meeting of the LWS Minds
Abstract:
The primary scientific objective of this proposal is to characterize the solar
eruptions that produce significant impact on the heliosphere in general, and
on Earth in particular, so that a global understanding of the phenomenon can
be developed. The specific impacts we are concerned with are the prompt arrival
of solar energetic particles (SEPs) and the delayed arrival of the energetic
plasma, known as the coronal mass ejections (CMEs). The multitude of effects
that directly affect the day-to-day life of the human society arise from the
geoeffectiveness and SEPeffectivess of the solar eruptions. To achieve the scientific
objectives we propose a two-pronged attack: (1) to hold a series of three Coordinated
Data Analysis Workshops (CDAWs) to pool data, models, and analysis tools together
for end-to-end studies of solar eruptions, and (2) to perform a targeted investigation
of the solar sources of complex geomagnetic storms that last for more than three
days with high intensity. CDAWs have proved to be an excellent forum for bringing
scientists together from various disciplines of the Living with a Star (LWS)
community for an in-depth look at science issues that cross the traditional
discipline boundaries. The CDAWs are relevant to the Cross-Discipline Infrastructure
Building Programs, because they address the timely and important topics of LWS.
The CDAWs also create value-added data products and publications in refereed
journals that become part of the LWS infrastructure. The targeted investigation
of CGS is directly relevant to the Focused Science Topic (d): Storm effects
on the global electrodynamics and the middle and low ionosphere. This proposal
is highly relevant to many of NASA's exploration objectives because the results
will help understand the space (radiation and plasma) environment along and
at the path of robotic and human exploration.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Raymond Greenwald/Johns Hopkins University
Title: Understanding the Evolution and Impacts of Storm-Enhanced Electric Fields
in the Mid-Latitude Ionosphere
Abstract:
The proposal is directed to the NASA LWS TR&T Targeted Investigation program
element and addresses the Focused Science Topic, ¿Storm effects on the
global electrodynamics and the middle and low latitude ionosphere¿, which
is identified by program descriptor T3d. We seek a deeper understanding of the
penetration of nominally high-latitude ionospheric electric fields into the
mid and low-latitude ionosphere and accordingly into the inner magnetosphere.
During quiet periods the electric field is largely confined to the high-latitude
zone and is highly variable in both time and space. During geomagnetic storms
the electric field penetrates into the inner magnetosphere where it produces
significant changes in magnetosphere-ionosphere coupling and major changes in
the subauroral ionosphere. Two of the major goals of LWS science are to understand
the processes that lead to these disturbances and to predict when they will
occur. Reaching these goals requires a significantly improved understanding
of the spatial and temporal evolution of both ionospheric and magnetospheric
electric fields during storms. We propose to analyze observations collected
with a new HF radar operating at the Wallops Flight Facility (¿=50¿)
for insight into the evolution of penetration electric fields. This radar, a
joint project of JHU/APL and NASA/WFF, extends the capabilities of the existing
Super Dual Auroral Radar Network (SuperDARN) for observing electric fields and
ionization irregularities into the mid-latitude region. The Wallops radar began
operations in early May of 2005 and has observed several types of subauroral
electric field arising from geomagnetic disturbance. The fields and their effects
are effectively imaged over large areas (~thousands of kilometers) with high
spatial (~tens of kilometers) and temporal (~minutes) resolutions. We shall
use data from the Wallops radar, the existing high-latitude SuperDARN network,
and related space- and ground-based instruments to characterize the activity
and to obtain a global-scale view of the structure and dynamics of disturbance
electric fields and plasma convection in the magnetosphere-ionosphere system.
Our research plan is specifically tailored to serve the research objectives
of the Focused Research Topic T3d. Specifically, we will (i) compile and characterize
a database of mid-latitude electric field events, (ii) characterize the occurrence
of subauroral polarization electric fields including their spatial and temporal
variability and effects on the ionosphere, (iii) describe the occurrence of
penetration electric fields and their ionospheric effects, and (iv) specify
the global electric field as a parameter that conditions the occurrence of subauroral
electric fields. This latter task will draw on mapping ionospheric convection
with SuperDARN modified by subauroral effects with projection into the magnetosphere
using established codes. We will also provide critical data and supporting analysis
to assist the efforts of the T3d Science Team, including the testing and development
of comprehensive models. We further propose to have the PI on this proposal
serve as Team Coordinator.
Living With a Star TR&T Program
NNH05ZDA001N
PI:
Lon Hood/University of Arizona
Title: Solar Induced Variations of Stratospheric Ozone: Improved Observational
and Diagnostic Analysis
Abstract:
The objective of the proposed work is to more completely determine and interpret
the observed stratospheric ozone response to solar variability on both the 11-year
and 27-day time scales as a function of altitude, latitude, and season. On the
27-day time scale, we will apply correlative and regression methods to (a) determine
the altitude dependence of 27-day ozone responses in the lower stratosphere
using a combination of SAGE II, UARS MLS, and EOS Aura MLS data; (b) determine
the dependence of the 27-day response on latitude, season, and QBO phase in
the upper stratosphere using primarily Version 8 SBUV(/2) ozone profile data;
and (c) distinguish statistically among possible solar forcing mechanisms (e.g.,
solar UV flux, solar and magnetospheric particle fluxes, Galactic cosmic ray
flux). On the 11-year time scale, we will apply a multiple regression statistical
model to re-evaluate the 11-year solar UV induced response of stratospheric
ozone using three complementary and independent data sets: (1) the recently
released Version 8 SBUV(/2) ozone profile data set extending from 1979 through
2003 (with anticipated updates); (2) the recently completed Version 19 UARS
HALOE data set extending from October 1991 through August of 2005; and (3) the
SAGE II ozone profile data set extending from 1984 through 2000. We will also
explore use of the HALOE and SAGE II data as external calibrations for the SBUV(/2)
data. In order to diagnose the physical causes of the observed 11-year ozone
response, we will carry out statistical analyses of other HALOE measured quantities
(e.g., NO + NO2, temperature) and will study the results of collaborative two-
and three-dimensional model simulations. We will specifically collaborate with
Drs. John McCormack of NRL and Dan Marsh of NCAR for this purpose. Preliminary
comparisons of a recent 50-year simulation of the NCAR WACCM v. 3 model, which
includes no QBO but incorporates the effects of energetic particle inputs and
uses observed sea surface temperatures as a lower boundary condition, shows
that the model 11-year ozone response is similar to the observed response. As
stated in the LWS TRT Summary (Appendix A.21 of the ROSES-2005 NRA), ``LWS will
provide understanding of the effects of solar variability on terrestrial climate
change . . .''. The observed solar cycle variation of stratospheric ozone is
a fundamental constraint on sun-climate models that include stratospheric effects
of solar ultraviolet and energetic particle inputs. The observed ozone response
to 27-day solar UV forcing is also a basic constraint on sun-climate models.
In addition, the need for the proposed research in the near future and the expectation
of a significant scientific impact are supported by: (a) the recent availability
of improved long-term remote sensing data sets including the Version 8 SBUV(/2)
and UARS HALOE data sets; and (b) preliminary comparisons of the observed 11-year
ozone variation with a recent 3D model simulation showing a potentially very
good agreement. The latter comparisons indicate that the planned approach toward
using collaborative model simulations for a variety of solar inputs and boundary
conditions to identify causal mechanisms will be fruitful.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Jack Ireland/L3 Communications Government Services Inc.
Title: Mapping the Inner Heliosphere: Implementing Ajax Technologies for LWS
Abstract:
Recent developments in web based client-server technologies have brought substantial
innovation to commercial websites. A landmark application of this new approach
known as Ajax, is the Google(TM) Maps website http://maps.google.com. The software
driving Google(TM) Maps allows users to pan, scan and zoom at will over what
appears to be a single, enormous image of the Earth in a natural and intuitively
appealing way. We will take open source equivalent technology into the realm
of Living With a Star (LWS) applications by creating a suite of image retrieval,
processing, display and storage algorithms that will implement the functionality
required to be able to view and monitor features on the Sun and inner heliosphere
simultaneously. This core suite of algorithms will be the engine that will power
new and natural ways of visualizing the Sun and the inner heliosphere for the
LWS program.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Jay Johnson/Princeton University
Title: Theory and Hybrid Simulations of Transport due to Kinetic Alfven Waves
at the Magnetopause
Abstract:
Recent observations have placed observational constraints on plasma entry mechanisms
for northward IMF conditions when the plasma sheet cools and densifies. In particular,
both in situ and remote observations have found dawn-dusk asymmetries in the
density and temperature of the ion populations, and in situ particle distributions
show perpendicular ion heating of low energy ions on the dawnside associated
with strong compressional wave activity in the magnetosheath. It is the purpose
of this proposal to examine transport processes that would occur due to kinetic
and nonlinear interactions associated with the large amplitude, low frequency
waves that are nearly always observed near the magnetopause in the context of
these observational constraints. We would address the following scientific questions:
(a) What is the nature of the low frequency wave activity and how does it regulate
plasma entry into the magnetosphere, (b) What are the observational signatures
expected from these transport processes?, and (c) How do the observational signatures
compare with simulation and theory? We will use a combined theoretical and computational
approach to understand how kinetic Alfven waves develop near the magnetopause
and contribute to transport. We will obtain wave solutions near the magnetopause
using the kinetic-fluid model (that include finite Larmor radius effects and
wave particle interactions) that we will use to understand transport and heating
at the magnetopause using methods of nonlinear dynamics. We will compare these
results with hybrid simulations in a simplified slab geometry to understand
the nonlinear aspects of low-frequency MHD waves at the magnetopause. Using
this insight, we will perform and interpret three-dimensional hybrid simulations
in a realistic magnetospheric geometry. We will examine the dependence of transport
on solar wind conditions and the location along the magnetopause where particle
entry occurs. We will compare our theoretical models with observations of wave
activity, particle distributions, and global asymmetries. This project is directly
relevant to the Living with a Star Targeted Research and Technology program
Focused Science Topic area (c) Solar Wind Plasma Entry and Transport in the
magnetosphere because we will address the means by which plasma crosses the
magnetopause and we will quantify the amount of solar wind entering the magnetosphere
due to low frequency kinetic Alfven wave activity and identify where it enters
along the boundary. This proposal is also relevant to NASA's national research
objectives to explore the dynamic earth system because we will have improved
understanding of space environmental conditions and their causes which will
increase capabilities for space flight and exploration.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Vania Jordanova/University of New Hampshire
Title: International Symposium on Recent Observations and Simulations of the
Sun-Earth System
Abstract:
We propose to organize an International Symposium on Recent Observations and
Simulations of the Sun-Earth System (ISROSES) in Varna, Bulgaria, from 18 to
22 September 2006. The main purpose is to create an international forum for
scientists from solar, heliospheric, magnetospheric, and earth sciences communities
to present and discuss recent advances in our understanding of the structure
and complex interactions of the Sun-Earth System. The focused discussions will
include, but are not limited to: (1) Solar Cycle variations in the Sun-Earth
system; (2) Solar dynamics and the response of geospace; (3) Production, transport,
and loss of energetic particles; (4) Sun-Earth system modeling and prediction.
The main emphasis will be put on the integration of these studies -- ranging
from observations to related interpretation, theory and numerical modeling --
across different temporal and spatial scales of the Sun-Earth system. Participants
should come away with a better realization of the dynamic nature of the space
environment, while appreciating the benefits of interdisciplinary approaches
to understanding the dynamic Sun-Earth system. ISROSES will include four full
days of presentations and discussions; each day will be devoted to a primary
topic with invited, contributed, and poster presentations. The invited presentations
will cover the solar, magnetospheric, and ionospheric aspects of the topic to
accomplish the cross-disciplinary objectives of the conference. The Principal
Conveners Vania Jordanova and Ilia Roussev will be aided by a Scientific Organizing
Committee (SOC) consisting of twelve well-established international scientists
who will organize and lead the four days of individual sessions. The on-site
coordination of the technical aspects of the conference will be planned by a
Local Organizing Committee (LOC) consisting of eight distinguished Bulgarian
scientists. The Conveners, in collaboration with the SOC will prepare a report
on the meeting for publication in the Space Weather Journal. We seek support
for students and young scientists to attend the symposium. The proposed Symposium
Themes are relevant to the NASA Strategic Objective to understand the effects
of the Sun on Earth and the environmental conditions that will be experienced
by astronauts, as defined in the NASA ROSES-2005. They mesh well with the Strategic
Goals of the NASA Living With a Star (LWS) Program, and with the NSF Solar,
Heliospheric, and INterplanetary Environment (SHINE) and Geospace Environment
Modeling (GEM) Programs. Specifically, they address the NASA LWS Program Focused
Topic T3c ''Solar Wind Plasma Entry and Transport in the Magnetosphere''. The
third ILWS General Meeting on 24 April 2005 in Vienna, Austria, approved to
sponsor ISROSES as an ILWS Workshop.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Homa Karimabadi/SciberQuest, Inc.
Title: A Novel Data Mining Tool with Autonomous and Analytical Capabilities
for Space Weather Studies
Abstract:
This proposal describes a research and development plan aimed at the Tools and
Methods component of the LWS Targeted Research and Technology program. Our main
objective is to adapt and bring in a new technology in data mining called Relevant
Input Processor Network (RIPNet), which has proven very effective in other fields,
into space sciences. Our recent application of this technique to space physics
has demonstrated superior performance metrics (speed, accuracy, etc.) compared
to standard techniques such as artificial neural net. The great speed advantage
of RIPNet over traditional techniques (minutes rather than many hours and days)
makes it an ideal desktop application and will be a key to its widespread use
among experimentalists. RIPNet also offers a powerful reverse engineering capability.
By this we mean that the outcome of the algorithm (i.e., the predicted model)
is an analytical function with proper dependencies on the input parameters.
The culmination of this work will be customized data mining software that can
be used as a stand-alone application or be integrated into existing and future
space physics data assimilation infrastructures (e.g., the Virtual Observatory).
Consistent with the notional areas of interest for NASA¿s Living With
a Star (LWS), our new technology should significantly increase science return
from the data and enable development of more comprehensive physics-based understanding
of the integral system linking the Sun to the Solar System through advanced
knowledge discovery techniques (e.g., autonomous event detection, reverse engineering
of time series data, etc.) that our software will provide. Although the focus
of this work is on the development of a new type of data mining software, our
research task also includes use of this software for a problem of great relevance
to the LWS program. That is modeling of relativistic electron enhancements at
Geosynchronous and Low Altitude Orbits which poses potential hazard to Earth-orbiting
satellites and cosmonauts. We, however, emphasize that our software will be
of general applicability and we plan to use it in the future for detection and
modeling of events in the solar wind (e.g., CMEs, shocks, etc.) among others
Our use of intelligent data analytic tools, i.e., computer algorithms which
probe more deeply into data than first generation methods, will constitute a
key step in modernization of data analysis in space physics. This in turn will
help expedite the march toward a mature model of the coupling between regions
and the global response of geospace to solar variations. As such, our work addresses
NASA¿s objective of exploring the Sun-Earth system to understand the
Sun and its effects on Earth, the Solar System and the space environmental conditions
that will be experienced by human explorers.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Enrico Landi/Artep, Inc.
Title: Solar Wind Origin and Acceleration Over the Solar Cycle
Abstract:
The knowledge of the source region, acceleration mechanism(s) and evolution
over the solar cycle are of fundamental importance to NASA's efforts to understand
the Sun and its effects on Earth and on human exploration. Here we propose a
three-year investigation on the origin and acceleration of the solar wind, and
of their evolution over the solar cycle. We will study the physical properties
of the solar coronal plasma from the limb out to 4 solar radii making use of
spectra from UVCS and SUMER, and images from EIT, Yohkoh and LASCO C1. The observations
were taken from 1996 to 2005 and cover nearly an entire solar cycle. The data
allow a comprehensive physical description of streamers and coronal holes, where
the solar wind originates, and tests of ion-cyclotron wave damping as a mechanism
for solar wind heating and acceleration.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Benoit Lavraud/Los Alamos National Laboratory
Title: Formation of Earth's Low-Latitude Boundary Layer and Cold, Dense Plasma
Sheet under Northward IMF
Abstract:
Observations have shown the occurrence of unusually cold and dense plasma in
the near-Earth tail of the magnetosphere. This cold, dense plasma sheet (CDPS)
is known to form during intervals of northward interplanetary magnetic field
(IMF) and to be of solar wind origin. It is further often observed to penetrate
close to Earth during conditions of enhanced convection. This proposal addresses
the science topic of solar wind plasma penetration and transport through the
magnetopause and subsequently into the inner magnetosphere in order to assess
the potential role of the CDPS in magnetospheric dynamics and geomagnetic activity.
It aims to answer the following specific scientific questions: A. How and where
does solar wind plasma enter the low-latitude boundary layer (LLBL) and plasma
sheet under conditions of northward IMF? B. How and when are the double high-latitude
reconnection, Kelvin-Helmholtz instability and wave-particle diffusion processes
operative? C. What is the contribution of each process in terms of plasma transfer
as a function of solar wind conditions? D. How is the CDPS material subsequently
transported inward and what is its effect on geomagnetic activity? E. Does the
CDPS have an influence on solar wind/CME geoeffectiveness through a preconditioning
of the magnetosphere? We will answer these questions through a combination of
data from key magnetospheric science missions (Cluster, Geotail) and solar wind
measurements (Wind, ACE), together with the large database of geosynchronous
plasma observations from the Los Alamos instruments. We will additionally test
the viability of specific processes by detailed data and model simulation comparisons.
This proposal directly contributes to the 'Solar wind plasma entry and transport
in the magnetosphere (T3c)' focused science topic of the 'Living with a star
targeted research and technology' NASA ROSES 2005 research announcement.
Living With a Star TR&T Program
NNH05ZDA001N
PI:
Jakobus le Roux/University of California, Riverside
Title: Self-Consistent Solar-Energetic Particle Acceleration at Evolving Shocks
Associated with Coronal Mass Ejections
Abstract:
Under the National Objective to ¿Study the Earth System from space and
develop new space-based and related capabilities for this purpose¿ the
proposed work is specifically concerned with the NASA objective to ¿Explore
the Sun-Earth System and its effects on Earth, the Solar System, and the space
environmental conditions that will be experienced by human explorers. The proposal
fits in with the Targeted Investigations element of the Living With A Star Targeted
Research and Technology (LWST) Program under which it addresses the Focused
Science Topic ¿Shock acceleration of solar energetic particles by interplanetary
coronal mass ejections (CMEs)¿. Time-dependent numerical solutions of
the equations of fundamental kinetic focused transport and acceleration theory
for energetic charged particles, kinetic wave excitation and transport theory,
and MHD theory for CME shock evolution will be employed to achieve a fully self-consistent
time-dependent model of solar energetic particle (SEP) acceleration at propagating
interplanetary CME shocks from the Sun to Mars with the minimum number of simplifying
assumptions. A few fully self-consistent SEP models that are based on transport
and acceleration theory exist, but are either analytical, or semi-numerical
such as the current University of California Riverside (UCR) model. The existing
models are subject to a number of assumptions such as near-isotropic particle
distributions at and downstream of the CME shock that need further investigation.
The SEP model that we propose, which can be viewed as a logical extension of
the current UCR model, will be used for this purpose, and for comparison of
simulation results with specific SEP events. Thus we expect to achieve an enhanced
understanding of the significant complexities of time-dependent SEP acceleration
that arises at an evolving CME shock (e.g., self-consistent wave generation
by SEPs streaming away from the shock and the role of quasi-perpendicular shocks),
and how this relates to the formation of radiation hazards between the Sun and
Mars.
Living With a Star TR&T Program
NNH05ZDA001N
PI:
Martin Lee/University of New Hampshire
Title: An Analytical Theory of Diffusive Shock Acceleration for Gradual SEP
Events
Abstract:
The goal of this project is to develop an analytical theory for the shock acceleration
of solar energetic particles (SEPs) at an evolving coronal/interplanetary shock.
The theory should provide an effective framework for understanding the essential
behavior of the large ''gradual'' SEP events which contribute to the most severe
storms in space. Although the theory will be idealized in many ways in order
to be amenable to analytical techniques, it will include the essential features
which control the morphology of these events: shock acceleration by shock drift
and the first-order Fermi process, wave excitation upstream of the shock by
the energetic protons, diffusive transport of the ions in the turbulent sheath
upstream of the shock, ion escape from the sheath by magnetic focusing, and
injection from both solar wind and suprathermal/energetic ion seed populations.
The theory will improve on previous analytical (and numerical) work in important
ways, both in calculating the excited wave intensity and generalizing the injected
populations. The theory will predict wave intensities, and particle energy spectra
and anisotropy for all ion species, as functions of distance upstream of the
shock. In particular the spectra of the escaping ions (which satisfy the ''streaming
limit'') will be determined. The project will be critical to the success of
Focused Science Topic (a) since it will provide analytical predictions which
(i) can be compared with the detailed current and future observations of several
spacecraft including ACE, STEREO, and Wind, and (ii) can be incorporated into
numerical schemes which can be applied to more complex and realistic geometries
and time variations.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Jon Linker/Science Application International Corporation
Title: MHD Modeling of Coronal and Heliospheric Magnetic Field Evolution
Abstract:
The ''open'' magnetic field is the portion of the Sun's magnetic field that
stretches out into the heliosphere to become the interplanetary magnetic field
(IMF). It plays a key role in the Sun-Earth connection. It defines the structure
of the heliosphere, including the position of the heliospheric current sheet
and the regions of fast and slow solar wind. Understanding of the topology and
dynamics of the Sun's open magnetic field requires time-dependent modeling of
the field response to changes in the photospheric magnetic flux. We propose
a three-year program to investigate coronal and heliospheric magnetic field
evolution with time-dependent MHD simulations. Specifically, we will: - Incorporate
magnetic flux evolution into the SAIC/NOAA SEC coupled MHD model of the solar
corona and inner heliosphere; - Study how the topological properties of the
magnetic field evolve in response to different components of flux evolution,
such as differential rotation; - Model the time-dependent response of the coronal
and heliospheric field to the flux evolution specified by the Schrijver and
DeRosa (2003) evolutionary model for several months of real time; - Use particle
tracing techniques to investigate the contributions of initially closed field
regions to the slow solar wind; - Compare the magnetic field topologies of the
resulting solutions (expanding loops, disconnection and interchange reconnection
events) with measurements from spacecraft to determine whether the simulated
evolution is compatible with heliospheric observations. Results from our simulations
will be provided to the space science community through journal publications
and our web site (http://iMHD.net/mhdweb).
Living With a Star TR&T Program
NNH05ZDA001N
PI:
Kan Liou/The Johns Hopkins University Applied Physics Laboratory
Title: A Photometry-based Model of Global Thermospheric Column O/N2 Driven by
Solar and Magnetospheric Conditions
Abstract:
The principal goal of the proposed research work is to construct a photometry-based
model of thermospheric atomic oxygen to molecular nitrogen column density ratios
(O/N2) using satellite-based measurements of far ultraviolet (FUV) dayglow emissions.
The proposed work will be carried out by processing and analyzing FUV images
of OI 135.6 nm and N2 Lyman-Birge-Hopfield dayglow acquired by Polar ultraviolet
imager (UVI), TIMED global ultraviolet imager (GUVI), and DMSP special sensor
ultraviolet spectrographic imager (SSUSI). The multi-satellite image data sets
provide unprecedented long term (one solar cycle) and simultaneous large spatial
coverage not previously available and ensure the statistical significance of
the planned result. The overall science objectives of the proposed research
are (1) to characterize and quantify O/N2 column density ratios for both quiet
and storm times, (2) to provide a tool for studying responses of thermospheric
composition to geomagnetic disturbances, (3) to provide a tool for predicting
(dayside) negative ionospheric storms, and (4) to provide validation for physics-based
models. Images of dayglow emissions at 135.6 nm and LBH bands from different
satellites will be cross-calibrated and converted to 2-dimensional maps of column
density ratios of O relative to N2, referenced to a fixed N2 depth, using the
updated empirical MSIS model of Hedin (NRLMSIS00) and the physics-based Atmospheric
Ultraviolet Radiance Integrated Code (AURIC). The derived O/N2 column density
ratios will be first resampled into regular bins and then assembled into a large
historical database. Finally, an empirical O/N2 model will be obtained via a
straightforward spherical harmonic fitting. Parameters that represent forcing
from the polar latitudes (the auroral electrojet AE and/or the polar cap PC
indices), the magnetosphere (the magnetic storm Dst index), and from the solar
wind plasma and magnetic field will be included in the fitting. The unprecedented
long term and large spatial coverage of the image data sets available for the
proposed work ensure the statistical significance of the expected result. The
proposal is aimed to support NASA LWS 2005 targeted investigation topic (T1):
''Tools and Methods.'' The proposal directly addresses the science priority
questions recommended by Geospace Mission Definition Team: ''(2A) Determine
the effects of long and short term variability of the Sun on the global-scale
behavior of the ionospheric electron density'' and ''(3A) Determine the effects
of solar and geospace variability on the atmosphere enabling an improved specification
of the neutral density in the thermosphere.'' To a broader scope, this proposal
addresses one of the NASA Strategic Objectives (IV): ''Study the Earth system
from space and develop new space-based and related capabilities for this purpose.''
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Dana Longcope/Montana State University
Title: Solar Flare Forecasting Using Topological Energy Models
Abstract:
This is a proposal to develop tools for forecasting the severity of solar storms
initiated from magnetic regions. The most severe storms occur when magnetic
energy stored in these so-called active regions is suddenly converted to other
forms such as radiation and outward moving material. Solar scientists still
do not understand enough of the relevant physics to predict the instant this
conversion will occur or the severity of the storm's effect on Earth. With the
present understanding, however, it is possible to estimate the amount of energy
currently stored in each region present, and how much of this energy is ready
for release. This grant would fund the development of a set of programs to make
such energy estimates continuously using routine photospheric magnetograms.
The estimate is based on a simplification of the full set of magnetohydrodynamic
equations known as the Minimum Current Corona, which places a rigorous lower
bound on magnetic energy stored by slow motions of the complex photospheric
field to which it is anchored. The energy is stored as field lines anchored
to different photospheric regions interact with one another. This proposal would
develop the methods for automatically identifying all photospheric regions and
quantifying their sizes, locations and internal and external motions. These
are translated into an energy estimate under the assumption that no reconnection
occurs between field lines anchored to different regions. These steps are computationally
simple enough to be performed continuously, automatically, in real time on a
small computer. It is then possible to estimate the energy which would be released
when any set of field lines were to reconnect at that instant. Such hypothetical
reconnection scenarios can also be characterized by the amount of twist (helicity)
which would be present in magnetic field ejected from the Sun --- a quantity
which may be significant in predicting the consequences at Earth of the solar
eruption. At the end of the funding the methods will be tested using observations
of past flares, and then made publicly available. Since it delivers a method
and software implementation useful in forecasting solar activity, this project
is well suited to the Tools and Methods component of the Targeted Research and
Technology program.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
John Lyon/Dartmouth College
Title: Plasma Transport from the Solar Wind to the Magnetosphere
Abstract:
The mechanism by which the solar wind plasma enters the magnetosphere remains
an important and to a large degree unanswered question. A number of mechanisms
have been proposed for this process. For example, there is direct entry along
newly reconnected field lines, there is diffusive entry (perhaps drift mediated)
along the magnetopause, there is impulsive penetration, to name a few. What
does seem clear is that the amount of plasma within the magnetosphere is correlated
with the density in the solar wind. This question of plasma entry has been called
out in the current NRA as an important science question of interest to the NASA
Sun-Earth Connection Program. We will attempt to determine the processes by
which entry, energization and energy extraction take place through a number
simulation codes, used singly and in concert. The simulation codes are: 1. A
global MHD magnetospheric code which has been used successfully to model many
of the aspects of magnetospheric structure and dynamics. This will be the workhorse
for this project. It can be used to track fluid elements from, say, positions
in the plasma sheet to their origins in the solar wind. 2. A particle tracking
code that integrates the Lorentz orbits of particles within the system. In conjunction
with the fields from the global MHD code, it can give ihe currentsnformation
about the actual trajectories of the particles making up the collisionless plasma.
3. Two fluid and hybrid codes to model the boundary layers (magnetopause) of
the global system. One of the deficiencies of the MHD codes is that the boundary
layers are both not resolved and deficient in physics. This makes the results
of tracing particle trajectories through such layers problematic. Our approach
will be two-fold. On one track we will use the global MHD model to set up idealized
situations where the plasma enetry can be studied using the full array of tools
listed above. Typically, then the MHD code would provide a base time-dependent
configuration of electric and magnetic fields, as well as fluid flows. The results
for plasma entry for the fluid model will then be compared against the results
for the particle tracing. The kinetic codes will be used in conjunction with
the particle tracing to develop ideas about the actual rates of particle penetration
and reflection and energy gain or loss through the boundary layer. In the second
track, we will try to validate the models by reference to actual data. This
is generally easier with the MHD models than with the other simulations. Here
we will rely on a combination of single event studies and upon statistical studies.
Living With a Star TR&T Program
NNH05ZDA001N
PI:
Ward Manchester/University of Michigan
Title: Modeling The 3D Density Structure and White-Light Appearance of CME Events
Abstract:
We propose to examine the propagation of solar eruptive events to 1 AU in a
realistic heliosphere using a global magnetohydrodynamic (MHD) model. The main
focus of this study will be the evolution of the 3D density structure of the
CME and how it relates to Thomson-scattered white light images. The University
of Michigan's BATSRUS code will used to perform the proposed simulations. CME
initiation will follow from both flux ropes and (Gibson & Low, 1998) and
imposed shearing motions. Our earlier simulations have produced many important
results. We have shown that the mass of fast CMEs increases by as much as a
factor of four as they propagate to Earth because of plasma swept up by the
CME-driven shock. We have also shown that line-of-sight measurements of CME
mass may significantly underestimate the mass swept up by a CME if a dense spherical
shell encases a low density cavity. Expansion of the CME flux rope has also
been shown to cause the dense core to evolve to a density depletion. These results
have been published a series of papers: Manchester el al. (2004a, 2004b) Lugaz,
Manchester and Gombosi (2005). This proposal seeks funds to significantly advance
this research in 4 ways: (1) incorporate a more realistic MHD model of the inner
heliosphere based on solar magnetograms, (2) investigate the pre-eruption conditions
at the Sun based on magnetic data for chosen active regions and use this data
to direct CME initiation, (3) comparing the CME synthetic white light images
with LASCO observations near the Sun and images obtained near 1 AU with STEREO.
We will examine the 3D model density structure of CME disturbances and line-of-sight
images to determine what may be accurately inferred about the density, velocity
and energy of CMEs from single and stereoscopic views. Understanding the CME
morphology will allow us to separate the shock from the driver and will lead
to more accurate measurements of the physical parameters such as the compression
ratio, speed, mass, and location. In the case of shocks, the compression ratio
and speed are necessary inputs in models of particle acceleration. Understanding
how the various CME structures evolve through the heliosphere will enhance the
scientific return from the numerous in-situ instruments. It will also help us
investigate what causes some CME to be geoeffective. Obtaining realistic CME
models throughout the heliosphere will greatly enhance the return from the SECCHI
observations by (1) providing examples of how certain CME structures (shock,
flux rope) will look at different heliocentric distances and perspectives, and
(2) act as a controlled data set upon which to test the fidelity of the 3D reconstruction
algorithms.
Living With a Star TR&T Program
NNH05ZDA001N
PI:
Anthony Mannucci/Jet Propulsion Laboratory
Title: Ionospheric Behavior During the First Few Hours of Intense Geomagnetic
Storms
Abstract:
The impact of electric fields on the large-scale variation of plasma in the
Earth's ionosphere is receiving increasing attention from the research community
because it is of fundamental importance in understanding the structure and dynamics
of the Earth¿s ionosphere during geomagnetic storms. Recent publications
suggest that prompt penetration electric fields generated by the solar wind-magnetosphere
interaction may have enormous consequences in changing the global structure
of total electron content (TEC) in the dayside ionosphere, rapidly (within ~2-3
hours) after certain conditions in the solar wind are met. In earlier work,
Foster et al., (2002) used a dense network of ground-based ionospheric measurements
to detect mesoscale structures over North America that may be correlated with
plasmaspheric structures known as drainage plumes, the latter widely believed
to be due to storm-time electrodynamics in the inner magnetosphere. Both the
dayside TEC increases, and the mesoscale mid-latitude structures, suggest the
strong role of convection electric fields in determining ionospheric behavior
during geomagnetic storms, but many questions remain about the origin of these
fields and their ionospheric impact. The focus of this proposal are the large-scale
and large-magntiude changes in TEC that occurs early on during intense geomagnetic
storms. Significant gaps in understanding these changes suggest the need for
establishing an empirical relationship between solar wind conditions that trigger
geomagnetic storms, and the resultant ionospheric response. Such an empirical
relationship has clear scientific value, because the magnitude and promptness
of the ionospheric response is not being predicted, in general, with existing
models of geospace. It also has practical value for predicting the severity
of near-Earth space weather given an upstream monitor of solar wind conditions,
as is available, for example, from the ACE spacecraft. Our approach will be
to use a globally-distributed dataset of ionospheric measurements, obtained
from the ground and from space, to relate the observed TEC behavior to upstream
solar wind conditions. The dataset is available from Global Positioning System
receivers on the ground and in orbit, and from dual-frequency ocean altimetry
satellites. Our focus will be on dayside, large-scale plasma increases and re-structuring
in the first few hours of intense storms. We will compare the observations to
models to determine the degree and manner in which existing state-of-the-art
models predict the observations and capture the physics.
Living With a Star TR&T Program
NNH05ZDA001N
PI:
Sergei Markovskii/University of New Hampshire
Title: Intermittent Heating of the Solar Wind in Coronal Holes
Abstract:
Much about the origin and nature of the solar wind, which is a key element of
the Sun-Earth connection, depends on a detailed knowledge about the energy sources
for the fast solar wind and the kinetic mechanisms responsible for its heating
and acceleration in coronal holes. A broad consensus has emerged over the past
decade attributing the solar wind heating to the cyclotron-resonant dissipation
of ion cyclotron waves. Although a number of investigations of this mechanism
have been carried out, two fundamental questions remain to be answered: What
is the source and character of the necessary waves? and What is the detailed
kinetic response of the ions? This proposal links small-scale magnetic reconnection
events (microflares) at the coronal base to the generation of the fast solar
wind. We explore the consequences of a new view that the microflares launch
a highly intermittent electron heat flux up into the corona. These sporadic
heat-flux bursts can excite highly-oblique ion cyclotron-resonant waves through
a plasma microinstability and energize the ions. We have already developed a
quantitative model of this process for the collision-dominated region near the
base of the corona. The collisional relaxation of the proton distribution function
in this region allowed us to simplify considerably the description of the solar
wind evolution. With this model, we have shown that our mechanism is efficient
enough to account for the initial acceleration of the fast solar wind. We now
propose to extend our analysis to the rest of the solar corona. In the absence
of collisions, a fully kinetic approach is required to describe the solar wind
evolution. We will use both analytical and numerical techniques to develop and
quantify this approach. When combined with our previous results, we will ultimately
have a kinetic model that will work in the entire region of the solar wind acceleration.
An essential goal of any coronal heating model is to explain the heating of
the ions perpendicular to the magnetic field and the preferential heating of
the heavy ions. For this purpose, we will incude O5+ and Mg9+ ions in our analysis.
The theoretically predicted behavior of these ions will be verified with the
help of the UVCS/ SOHO observational data. To test our theory, we will further
derive the amplitudes of the density fluctuations associated with the heat-flux
generated ion cyclotron waves and compare them with the interplanetary scintillation
measurements. Studying the solar wind energization helps prevent the potential
exposure of humans to harmful effects of the solar activity in the outer space.
Thus, this work is important for the success of the future space exploration
mapped out in the new national program of prolonged human activity on the Moon
and on the roundtrip to Mars. By guiding and enhancing the observational capabilities
of the NASA missions, this research will provide the information for policy
formulation of federal agencies coordinating the national program of space exploration.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
William Matthaeus/University of Delaware
Title: Turbulent Heating of the Corona, Origin of Solar Wind Fluctuations, and
Boundary Conditions in the Inner Heliosphere
Abstract:
This proposal is to support collaborative work on the origins of the solar wind,
and the boundary conditions for Space Weather effects in the inner heliosphere,
to be carried out during a one year sabbatical that the PI has been granted
by the University of Delaware for calendar year 2006. The University will supply
75% of the PI's salary in support of the sabbatical, and this proposal requests
support for the remaining 25%. During the year the PI will spend approximately
five months at the University of Florence to work collaboratively with Prof.
Marco Velli. The PI and Prof. Velli both served on the Solar Probe Science and
Technology Definition team and contributed substantially to the science component
of that effort. The goals of this proposal are based on science issues that
came up and became partially clarified while writing the solar probe Science
and Technology Definition Team document, providing a unique opportunity to continue
the momentum that was established in that series of meetings. The proposed research
is: (1) to develop a better theoretical understanding of the behavior of Alfven
waves and turbulence in the important regions between the sonic and Alfven points
(approx. 5-20 Rs) in the corona, and between the Alfven point and 1AU in the
solar wind. This includes study of observed 1/f noise, the development of anisotropy,
and the nature of high latitude turbulence. These will be addressed through
a combination of observational and numerical inputs, and analytical modeling;
(2) to assemble a fully consistent model of the acceleration of the solar wind,
using for the first time an accurate, consistent and tested nonlinear model
for MHD turbulence starting in the lower corona. Unlike other similar models,
we will include cross helicity and anisotropic cascade effects. These are issues
that the PI has worked on in great detail with his collaborators, and in this
new collaboration M. Velli will supply valuable expertise in wind equations
and modeling of large scale coronal magnetic field. The further understanding
of the plasma physics and turbulence theory of these regions will provide extremely
valuable insights concerning the ''inner boundary conditions'' for space weather,
and is therefore an essential underpinning of the LWS TRT science in general,
directly addressing the 2005 targeted research area: ''T3b. Determine the mechanisms
that heat and accelerate the solar wind.'' This is a one year proposal, but
the PI agrees to maintain participation in the associated working group.
Living With a Star TR&T Program
NNH05ZDA001N
PI:
Richard Mewaldt/California Institute of Tech
Title: Modeling and Observations of Solar Energetic Particle Spectral Breaks
Abstract:
Recent measurements show that in essentially all large solar energetic particle
(SEP) events the energy spectra have a power-law component at low energies followed
by a significant break in the spectra at higher energies (e.g., between ~5 to
50 MeV for protons). The spectra above the break sometimes are exponential in
shape, but often a second power-law extends to hundreds of MeV/nucleon. The
location of spectral breaks and the spectral shape above the break play key
roles in determining whether an SEP event represents a radiation hazard. We
propose to combine a self-consistent, detailed model of shock acceleration and
interplanetary transport with state-of-the-art SEP measurements to investigate
why spectral breaks occur, which physical parameters affect their location,
and what determines the spectral shape at high energies. The SEP data are from
the EPAM, ULEIS, and SIS sensors on ACE and instruments on GOES and SAMPEX.
These data will produce energy spectra from ~0.1 to ~100 MeV/nucleon for H,
He, and heavy-ions from C to Fe. The observations already demonstrate that all
ion species typically share a common spectral form, with spectral features that
are organized by charge-to-mass ratio (Q/M). These spectra thereby provide critical
information for investigating the physics of SEP acceleration and transport.
To investigate SEP spectra theoretically we propose several improvements to
the SEP acceleration and transport model of Li, Zank and Rice. This model produces
SEP spectra very similar to those observed, with spectral breaks that are apparently
related in part to the spectrum of Alfven waves generated by protons escaping
upstream of the shock, a critical element of the shock acceleration process.
Other aspects of the acceleration process that will be investigated include:
the seed-particle energy spectrum; the level of pre-existing upstream turbulence;
shock speed and strength; and the rate and rigidity dependence of particle escape
from the shock. By systematically varying the initial conditions and model parameters
and then comparing with observations of large SEP events, we will isolate the
parameters and conditions that have the strongest effect on SEP spectral characteristics.
This work will address several key scientific questions about SEP acceleration
by CME-driven shocks, including: What seed-particle spectra and composition
are needed to match the observations and how are they altered during the acceleration
process? What conditions govern the acceleration rate, spectral slopes, break
energies, intensity, and temporal evolution of SEP events? What combinations
of these parameters result in very large SEP events like those on October 28,
2003 and July 14, 2000? Answering these questions is a prerequisite to building
real-time models that can forecast when large SEP events will occur and how
they will evolve - goals of both LWS and the 2005 S3C Strategic Roadmap.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Mari Paz Miralles/Smithsonian Astrophysical Observatory
Title: An Observationally-Driven Predictive Capability for the Acceleration
and Heating of Fast and Slow Solar Wind Streams
Abstract:
We will combine: (1) measurements of plasma parameters in the acceleration region
of the solar wind, made over the last decade of UVCS/SOHO observations, (2)
measurements of in situ solar wind properties, and (3) ab-initio theoretical
models of MHD turbulent heating in solar wind flux tubes, in order to understand
the mechanisms that heat and accelerate the solar wind. The study will test
and refine theories that propose that the geometry of coronal flux tubes is
primarily responsible for the range of fast and slow wind speeds. Thus, this
study will put new constraints on similarities and differences in the acceleration
of fast and slow solar wind streams.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Mark Psiaki/Cornell University
Title: Development of a Limb Scanning Occultation Receiver for Ionospheric/Atmospheric
Remote Sensing using Galileo and Modernized GPS Signals
Abstract:
New radio receivers will be designed and tested for acquiring and tracking weak
GPS and Galileo signals during limb scans that occur just before or after occultation
of the line-of-sight from the low-Earth orbit (LEO) receiver platform to the
transmitting satellite. These receivers will be useful for global-scale remote
sensing of the ionosphere and the neutral atmosphere from LEO satellites. The
receivers will be developed to use the existing GPS civilian L1 signal along
with the new GPS civilian L2 and L5 signals. They will also use multi-frequency
signals from the Galileo global navigation satellite system that the Europeans
are building. These receivers will be specially designed to track very weak
multi-frequency signals down to low minimum scan altitudes in the neutral atmosphere,
and to return scientific data such as TEC, neutral atmosphere delay, and amplitude
and phase fluctuations. One receiver will be designed using FPGA technology,
and another will be designed using real-time software receiver technology. They
will be capable of processing many occulting signals simultaneously from both
GPS and Galileo satellites. One possible FPGA design will operate in a sequential
batch mode on digital intermediate frequency data that is stored in a circular
buffer. Batch operation allows a single-channel FPGA that implements a complex
set of operations to function as a multi-channel device because it can perform
its calculations many times faster than the rate at which data are logged. The
goal of the design is to receive signals and produce science data for all GPS
and Galileo occultations that occur in a typical LEO. The new receiver will
be able to return 3 times as many limb scans per day as can current occultation
receivers while using lower gain antennas and simpler radio-frequency processing.
The use of newer high-quality GPS and Galileo signals will enable these goals
to be achieved. The principal science advance of the project will be an increase
by a factor of 3 or more of the global density of limb scan coverage for a given
polar-orbiting LEO platform and an increased ability to field the new receivers
on LEO platforms due to decreased cost and complexity. The net result will be
a greatly improved ability to estimate dynamic global variations of ionospheric
electron density, of neutral atmosphere temperature and pressure in the upper
troposphere and the stratosphere, and of water vapor in the lower troposphere
(if independent temperature measurements are available).
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Cora Randall/University of Colorado
Title: Implications of Energetic Particle Precipitation for the Stratosphere
Abstract:
We propose to combine satellite data analysis and global modeling to investigate
the effects of solar cycle variations in energetic particle precipitation (EPP)
on the stratosphere. Precipitating particles continually penetrate the earth's
upper atmosphere, producing odd nitrogen. During the polar night, if dynamical
conditions are appropriate, the odd nitrogen so produced can descend to the
stratosphere where it participates in the catalytic cycles responsible for controlling
ozone distributions. While this has been known for decades, the implications
for stratospheric ozone have never been quantified, and these effects are routinely
neglected in three-dimensional global models. Nevertheless, observational evidence
suggests that even under moderate levels of solar activity, EPP affects stratospheric
ozone. The goal of this proposal is to investigate the effects of EPP on stratospheric
ozone distributions, variability, and trends, and the resulting implications
for studies of long-term change in the upper troposphere and stratosphere. To
accomplish this, the proposed work has two main objectives: (1) Analyze the
historical and continuing data base of stratospheric ozone and NOy satellite
measurements to correlate variability in these constituents with solar cycle
variations in EPP; and (2) Incorporate EPP into a global chemistry climate model
to quantify EPP effects on stratospheric NOy and ozone distributions, and to
investigate corollary effects on atmospheric composition and dynamics. Through
the combined use of satellite data and modeling, the proposed work is directly
responsive to the current NASA ROSES Research Announcement and Living With a
Star (LWS) program objectives. It targets the NASA exploration objective ''To
understand and protect our home planet'' by addressing ''the role of solar variability
in climate and stratospheric chemistry'', one of the primary focus topics designated
by the LWS Targeted Research and Technology Science Definition Team.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Edward Rhodes/University of Southern California
Title: The Study of the Changing Solar Interior Using Global and Local Helioseismology
Abstract:
The research we are proposing has the main goal of improving our knowledge of
the temporal changes which are occurring in the structure and dynamical motions
of the solar interior. Within the past few years, several hints of possible
temporal changes that have occurred during the current solar cycle have been
obtained through the application of helioseismic techniques to observations
made with the Michelson Doppler Imager (MDI) experiment onboard the SOHO spacecraft.
These hints have included the discovery of the Solar Subsurface Weather (SSW),
and the confirmation of the existence of the torsional oscillations in the sub-photospheric
layers. The discovery of the SSW has included a reversal in the meridional circulation
beneath the solar surface in the northern hemisphere during the years 1998 through
2001. We have recently verified that the torsional oscillations can be seen
in cotemporaneous ground-based observations taken at the Mt. Wilson Observatory
(MWO) 60-Foot Solar Tower after the SOHO launch as well as in observations obtained
prior to the SOHO mission. We have verified the existence of the torsional oscillations
in our 60-Foot Tower data by first transferring two and one-half years of these
observations to the MDI Science Center and by then computing the frequency splittings
of the solar f-mode oscillations. We have also verified that these same MWO
observations can be employed in the generation of the ring diagrams of local
helioseismology. We have generated maps of sub-photospheric flows from MWO Dopplergrams
obtained during three different Carrington Rotations in 1995, 1996, and 2001.
We propose to search for changes in both the meridional flow and in the torsional
oscillations during Solar Cycle 22 using earlier MWO observations since our
60-Foot Tower observations are the only suitable data available during that
solar cycle. We also propose to improve the radial resolution of the measurements
of the shallow sub-surface layers by incorporating measurements of the frequency-splitting
coefficients of the high-degree p-mode oscillations now that we have been able
to remove the contamination introduced into those measurements by solar differential
rotation. Since the high-degree p-modes are confined to the shallow layers just
below the photosphere, the inclusion of their frequency splittings should allow
us to improve upon the depth resolution available from the use of the intermediate-degree
f-mode splittings alone. We also propose to invert the high-degree frequency
splittings in order to provide an independent verification of the zonal velocities
which are measured by the ring-diagram methodology. During the first 28 months
of this project we have transferred 1118 days of 60-Foot Tower Dopplergrams
containing in excess of one terabyte of data to the MDI Science Center. All
of these images are currently available for use by the entire solar community.
During our planned continuation of this project, we expect to transfer all of
our remaining archive of 60-Foot Tower Dopplergrams to the MDI Science Center.
This transfer and our other planned tasks will all extend research which has
been supported by NASA Living with a Star Program Grants NAG5-13510 and NNG04GM01G.
Living With a Star TR&T Program
NNH05ZDA001N
PI:
Jim Roeder/Aerospace Corporation
Title: Relativistic Electron Acceleration and Transport: CRRES and SCATHA Observations
in the Inner Magnetosphere
Abstract:
Observations by the NASA/USAF SCATHA and CRRES satellite missions will be used
to test candidate mechanisms for the acceleration and transport of radiation
belt electrons in the energy range 0.05-6 MeV. Radial profiles of the measured
energetic electron phase space density will be constructed at constant first
and second adiabatic invariants. The profiles at a range of values for the second
invariant, from near zero to large values, will help determine whether local
wave particle interactions actively contribute to the electron acceleration.
Electron and wave data from SCATHA and CRRES will also be used to test diffusion
models of the wave-particle interactions in pitch angle and energy. The effect
of magnetic and electric shell splitting will be investigated by examining the
local time asymmetries of SCATHA and CRRES electron observations of in comparison
with other available satellites.
Living With a Star TR&T Program
NNH05ZDA001N
PI:
Ilia Roussev/University of Michigan
Title: A Self-Consistent Investigation of SEP Production in Gradual Events Based
on Realistic Models of Turbulence and IMF
Abstract:
We propose to study the shock acceleration of solar energetic particles (SEPs),
and their transport, coupled to the dynamics of CME-driven turbulent shock waves
in the heliosphere. Our goal is to develop a self-consistent model, which integrates
the best theories developed for every aspect of the SEP production and transport
problem. This will include a realistic model of turbulence near the shock front
and effects of SEP spectrum anisotropy. The new SEP-turbulence model will be
coupled with a realistic model of CME evolution to enable the LWS community
to tackle important problems related to the shock acceleration of SEPs by CME
shocks. Our research studies will target fundamental features of gradual SEP
events, such as formation and evolution of CME-driven shocks, particle injection
at the shock, excitation of turbulence by the self-generated Alfvén waves,
particle diffusion due to the enhanced turbulence, and particle escape upstream
of the shock, among other phenomena. The strength in our integrated approach
is that it will enable us to quantify the particle acceleration and scattering
by the self-excited Alfvén turbulence, and particle transport along and
across the interplanetary magnetic field (IMF). We will extend the capability
of the kinetic code of the University of Arizona to include a realistic model
of self-excited turbulence, since this code is well suited to handle a finite
particle spectrum anisotropy. The particle transport upstream of the shock wave
will be studied using a newly developed statistical code based on the Monte-Carlo
approach. All the models coupled together will allow us to account for the acceleration
and transport of charged particles in realistic 3D turbulent IMF. The results
of our studies will be compared with available data from SoHO, ACE, and other
satellites in order to improve the CME-SEP-turbulence model accordingly. The
whole research effort is expected to contribute towards better understanding,
predicting, and mitigating the exposure of human explorers to harmful radiation
of solar origin. The proposed self-consistent investigation of SEP production
in gradual events based on realistic models of turbulence and IMF directly relates
to Focused Science Topic T3a of the LWS TR&T solicitation. We are also devoted
to contributing significant time and effort towards improving science education,
particularly in solar-heliospheric physics, and we offer an Initiative for a
Novus-Seculorum Program in solar Research and Education (INSPiREd). We propose
to organize specialized summer schools, which will introduce and involve students
in an integrated-system perspective of the Sun-Earth system. The schools will
also provide a venue for teaching and research faculty to improve the scope,
impact, and outreach of the existing academic programs. These objectives will
make the INSPiREd an important complementary addition to the existing education
and public outreach activities at NASA, NSF, and US academic institutions.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
James Ryan/University of New Hampshire
Title: Summer School in High-Energy Solar Physics at the University of New Hampshire
Abstract:
We propose to organize a summer school for graduate students and new postdocs
in high energy solar physics. The material presented will cover the instrumentation
related to, the observations of, and the associated fundamental physics of solar
flares, coronal mass ejections, and solar energetic particles. The school will
be held in New Hampshire from 14 ~ 24 June, 2006, immediately prior to the American
Astronomical Society Solar Physics Division meeting at the same location. We
request funding to support the travel and per diem costs for some 45 students
and ~10 faculty, and to cover the publication of refereed versions of the lectures
in a single volume. This Solar Physics Division of the American Astronomical
Society has approved this event as its sponsored summer school for 2006. Financial
support from NSF has also been promised.
Living With a Star TR&T Program
NNH05ZDA001N
PI:
Stanislav Sazykin/Rice University
Title: Modeling the Impact of Stormtime Electrodynamics on the Mid and Low Latitude
Ionosphere
Abstract:
The goal of this research is to determine the circumstances leading to the massive
restructuring of the mid and low latitude ionosphere and the development of
large-scale bite-outs of electron density at low latitudes during geomagnetic
storms. Good examples of these features occurred during the Halloween storm
in October 2003. Maps of total electron content (TEC) showed a factor of four
increase at mid latitudes, and measurements of electron density by the DMSP
satellite at 850 km indicated the ionosphere had virtually disappeared over
a wide latitude swath at low latitudes. The depleted region, or ''bite-out,''
was accompanied by smaller scale ionospheric irregularities, or bubbles, on
its flanks. It is expected that the dramatic gradients were created by exceptionally
large upward ExB plasma drifts, raising the ionosphere to higher altitudes,
transporting plasma poleward, and driving the huge depletions at low latitude.
This study will investigate the interaction and feedback between the two main
sources of the plasma drift -- the prompt penetration (PP) and disturbance dynamo
(DD) electric fields, and determine the cause of the massive restructuring of
plasma at mid and low latitudes during storms. This project is a ''linked''
proposal between research teams at University of Colorado (PI Tim Fuller-Rowell)
and Rice University (PI Stan Sazykin). The success of the project relies on
the self-consistent coupling between physical processes in the thermosphere,
ionosphere, and plasmasphere (as captured in the CTIPe model) and the inner
magnetosphere (as captured in the RCM). Combining these two models includes
both dynamo and penetration electrodynamics, and consistently handle the feedback
between the two regimes. This study is therefore unique in its ability to couple
the various domains and address the science questions in a rigorous mathematical
approach. This study will: 1) Determine the physical processes leading to the
large vertical plasma drifts and the interaction and feedback between the penetration
and dynamo electric fields, 2. Determine the impact on the mid and low latitude
ionosphere including the cause of the massive restructuring of plasma density,
and 3) Investigate the possible causes of the strong longitude dependence in
the storm-time response. The first phase of the study will perform the comprehensive
coupling of the CTIPe and RCM models where the polar cap boundary, the neutral
wind driven dynamo currents, and the field-aligned magnetospheric currents are
consistent between the two codes. The effects of under and over shielding in
the inner magnetosphere will be implicitly included in the field-aligned currents
and the potential solver. Numerical experiment will be performed with a goal
of understanding the complex interaction between the geophysical domains including
the electrodynamic feedback between PP and DD. For validation, the coupled model
will be used to simulate the recent storms targeted by the recent CDAW workshop.
The chosen storms have good global and regional coverage for TEC, have reasonable
measurement of the electric fields, and have well developed experimental/observational
databases. The potential benefit of this study for space weather is clear. Large-scale
changes in the ionosphere impact GPS navigation signals and alter the propagation
of HF radio-wave communication. The large-scale ionospheric changes are also
associated with the generation of small scale ionospheric irregularities responsible
for scintillations on satellite communication signals. Understanding the physical
processes will lead to the possibility of improvement in predicting and forecasting
the storm-time plasma redistribution and the creation of irregularities. This
proposal targets the specific research topic of the LWS TR&T Focused Science
Topic ''Storm effects on the electrodynamics and the middle and low latitude
ionosphere''.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Peter Schuck/Naval Reseach Laboratory
Title: Tracking Photospheric Magnetic Footpoints with the Magnetic Induction
Equation
Abstract:
We propose a three-year program to develop techniques for accurate and precise
estimation of solar surface flows from magnetogram data. Local Correlation Tracking
(LCT) is the de-facto standard for estimating motion in solar image sequences.
However, this technique has many documented limitations. Perhaps the greatest
limitations of LCT are the absence of demonstrated accuracy, precision and a
quantifiable local uncertainty associated with the velocities derived from this
technique, and the introduction of artificial scales. This program will develop
new techniques that are less susceptible to these limitations. The proposed
techniques determine the optical flow by applying the magnetic induction equation
and an affine velocity model statistically to a windowed subregion of the magnetogram
sequence producing an overdetermined system that can be solved directly by standard
least squares or total least squares techniques. These subspace methods are
inherently statistical. Consequently, the optical flow estimates can be assessed
for reliability and for resolution of the aperture problem. The result is a
point-by-point optical flow field that is consistent with the magnetic induction
equation. Our new algorithms will be benchmarked against synthetic data to establish
the accuracy of the technique and compared against the accuracy of previously
developed optical flow techniques such as LCT, Inductive Local Correlation Tracking
(ILCT), Minimum Energy Fit (MEF). Our new techniques will make full use of high-resolution,
high-cadence vector magnetogram data and line-of-sight magnetograms for the
dual purposes of scientific analysis and and to augment space-weather prediction
through real-time monitoring of photospheric activity. The output of this program
with be the new methods and the extensively documented performance characteristics
of the algorithm. Furthermore, magnetograms will be analyzed and the estimated
velocity fields and associated uncertainties will be provided to the solar physics
community for the purpose of driving realistic MHD simulations. The prime measure
of success for this work would be the widespread use of these ``tools'' for
the determination of solar surface flows from observational data. Therefore,
the library of tools developed under the program will be accessible to the solar
physics community. This program addresses the goals of the ``Tools and Methods''
component of the Living with a Star (LWS) Targeted Research and Technology Program
(TR & T). The goal of our program is to develop the tools and scientific
understanding needed for the United States to effectively address those aspects
of the Sun-Earth System that may affect life and society. The proposed work
will provide the necessary tools to deliver significant new understanding of
solar eruptions and resolve persistent controversies concerning the spatial
scales and flow velocities.
Living With a Star TR&T Program
NNH05ZDA001N
PI:
Yuri Shprits/University of California Los Angelos
Title: Quantifying Losses and Sources of Relativistic Electrons Using Kalman
Filtering
Abstract:
In this study we propose to create tools and develop methods which will enable
critically need science advances (A. 21_1.2.1 LWS TR&T announcement) in
the radiation belt research and may be applied in other fields. The created
tools will optimally assimilate and portray data from different sources for
LWS research and forecasting objectives (A. 21_1.2.1 LWS TR&T announcement).
The developed software will be capable of globally reconstructing equatorial
radiation belt fluxes with high time resolution for future use in analyzing
results from the future LWS RBSP mission. We will use satellite data from CRRES,
HEO, SAMPEX, Polar, LANL and GPS combined by means of Kalman filtering with
a radial diffusion model. The results will provide an insight into the physics
of the acceleration and loss mechanisms in the outer radiation zone (a key Objective
5.14 of the NASA Strategic Plan, Understanding the fundamental physical processes
of space plasma physics) and can be also used to develop new empirical models
(A. 21_1.2.1 LWS TR&T announcement) of the radiation belts. Our estimation
of the accurate initial conditions may be used for advancing radiation belt
nowcasting (NASA report TM-2002-211613 Section 3.2.2 of the LWS mission Definition
Team). Using these tools we will be able to estimate the errors of the various
detectors on the various satellites which will be used for the parameter estimation
of the model. We will apply extended sequential Kalman filtering techniques
to find unknown parameters of the system and thus compensate for missing or
misrepresented physics in the model. The data from different satellites will
sequentially change the parameters of the system and drive them to their true
values. This study will deliver tools and methods for understanding and quantifying
the high energy electron radiation belt fluxes. The methodology developed in
this study can be also used for advancing other areas of LWS research, where
sparse and low resolution data can be combined with physics based model to globally
reconstruct observations and to find the unknown physical parameters of the
system. The proposed research is central for the LWS objectives as suggested
in the NASA report TM-2002-211613 Section 3.1 of the LWS mission Definition
Team: Data assimilation models combine measurements, empirical models, and mathematical
optimization methods and first principles models to provide the most realistic
possible picture of the present condition or updates and corrections to the
propagation of conditions forward in time. In this way these models improve
nowcasting and forecasting.
Living With a Star TR&T Program
NNH05ZDA001N
PI:
Mikhail Sitnov/University of Maryland
Title: Dynamical Data-based Modeling of the Magnetospheric Magnetic Field with
Enhanced Spatial Resolution
Abstract:
This project will advance empirical models of the geomagnetic field, making
it possible to systematically increase their spatial resolution and to take
into account the variable solar wind driving on the timescales involved in storms
and substorms. The existing empirical models are global in space, time, and
in the amplitude of field variations, and they are fitted to observations using
a limited set of custom-tailored basis functions representing each magnetospheric
current system. They do not properly reproduce a wide difference in the response
of the individual field sources to solar wind driving. Removing these limitations
is the main goal of the proposed project. It will be achieved in three steps.
First, we will explore the timescales of the response of the main magnetospheric
field sources to solar wind density, speed, ram pressure and the interplanetary
magnetic field variations. The response functions will be parameterized using
simple loading-unloading equations with respect to the solar-wind input. Second,
we will implement a spectral technique, in which the fields of individual current
systems are expanded into a series of basis functions, taking into account geometrical
constraints, imposed on a given current system via its specific boundary conditions.
The number of those basis functions can be made sufficiently large, providing
the desired flexibility to the model. Combined with a progressive extension
of the spacecraft database, that will improve the spatial resolution, maximize
the information derived from observations, and minimize the number of a priori
assumptions on the structure of the magnetosphere. Third, we will explore the
possibility to replace the global time and amplitude fitting with the local
one, using the dynamical system approach and modern techniques of the local
fitting of data in the phase space, based on the concepts of time delay embedding,
nearest neighbors, and conditional probability. An important technical improvement
will be the parallelization of the existing and newly developed codes, providing
a much faster update of the model using supercomputers. The proposed study will
be based on the largest available amount of spacecraft data, using interplanetary
and magnetospheric observations and covering more than 50 major storms. The
final product, high-resolution dynamical empirical models of the geomagnetic
field will serve as a backbone for many applications aimed to quantify the particle
entry and transport in the magnetosphere, being particularly useful and efficient
for tracing energetic particles from the magnetopause to the ring current and
radiation belt regions for different solar wind and geomagnetic activity conditions,
including storm and substorm effects. Thus, the proposed project is directly
relevant to the Focused Science Topic T3c of the LWS TR&T program.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Elsayed Talaat/The Johns Hopkins Universtiy Applied Physics Laboratory
Title: Sub-Auroral Polarization Streams Effects on the Ionosphere and Thermosphere
Abstract:
The coupling processes within the magnetosphere/ionosphere/thermosphere system
are a key area of research in the Sun Earth Connections theme. One dramatic
manifestation of this coupling is enhanced sub-auroral electric fields, labeled
sub-auroral polarization streams (SAPS) or sub-auroral ion drifts (SAID) (Galperin
et al., 1973; Spiro et al., 1978, respectively). These events are of great importance
in determining the temporal evolution of the ring current and thermal plasma
distribution in the magnetosphere, ionosphere and plasmasphere. In this proposal
we will create a climatological picture of SAPS/SAID, including their conjugacy,
frequency, and intensity. We will also investigate the mechanisms behind their
formation and duration and the effect that SAPS/SAID have on ionospheric density
and thermospheric composition through analysis of multi-satellite observations
and simulations using the NCAR Thermosphere Ionosphere Electrodynamics General
Circulation Model (TIE-GCM).
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Lawrence Townsend/University of Tennessee
Title: Advanced Forecasting Methodologies for Solar Particle Event Radiation
Exposures
Abstract:
This proposal is a successor to our previously funded proposal, Advanced Warning
Methodologies for Solar Particle Event Radiation Exposures (NAG5-12477). The
previous work focused on the development of methods using Bayesian inference
and artificial intelligence for reliably predicting proton flux, dose and dose
rate versus time profiles for use in predicting ionizing dose effects in humans,
electronics or other components due to solar energetic particle (SEP) event
protons. That work was successful in that the methods developed were shown to
be capable of providing reasonably accurate ¿nowcasts¿ of doses
from SEP events that are independent of the magnitudes of the events. The methodology
is also unaffected by shielding configurations since it depends only upon the
magnitudes of the local dose values used as input and is independent of their
sources. The work proposed herein would extend our current methodology in two
areas: (1) improving numerical techniques to permit faster and more robust calculations
and (2) making a connection between our work and ongoing work in the space physics
community. The goal of these parallel efforts is to make faster and more reliable
forecasts of flux, dose, and dose rate versus time profiles through the use
of more efficient numerical methods and the connection to applicable solar observables.
We also propose to deliver a prototype dose forecasting software package with
an associated user and training manual at the completion of this investigation.
This would be the first step in transferring a research product to a user. The
proposed work supports the goals and objectives of the Sun Earth Connection
(SEC) Living With a Star (LWS) program through the development of knowledge
of advanced warning capabilities for SPE radiation exposures to human in space,
thus linking to the goals of the NASA Vision for Space Exploration. Predicting
the occurrence and magnitude of SEP events prior to coronal mass ejection (CME)
and/or flare occurrence is presently beyond the space science community¿s
capabilities. While our currently funded project has made significant progress
towards providing a reliable warning system capable of accurately predicting
particle fluxes and doses shortly after SPE particles begin to arrive, we see
two urgent needs: (1) the investigation of more efficient numerical techniques
and (2) the investigation of connections between our work and ongoing work in
the space and solar physics communities. The proposed work involves investigations
of solar energetic particle effects in human radiation exposures and therefore
is directly relevant to human exploration missions in deep space including extended
human expeditions to the lunar surface and Mars. The methods could also be used
for missions in low-Earth orbit, such as the International Space Station. The
methods are also applicable to radiation exposures of spacecraft electronics,
for both human and robotic missions.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Tycho von Rosenvinge/NASA/Goddard Space Flight Center
Title: Study of SEP Events and Shocks in the Inner Heliosphere
Abstract:
We propose a number of observational studies that will address goals of the
LWS Focused Science Topic ¿Shock acceleration of solar energetic particles
by interplanetary CMEs¿. Although a number of shock acceleration models
of increasing sophistication exist, they must be driven by, and tested against,
observations. Our studies will use an extensive database of energetic particle
observations from current and previous missions that extends over more than
three solar cycles. In particular, the Helios 1 and 2 spacecraft provide crucial
information about SEP events and shocks within heliocentric distances of 0.3
¿ 1 AU. One goal of the studies will be to characterize intensity-time
profiles of SEP events as a function of radial distance and azimuth relative
to the related solar event. We will also investigate the global properties of
the related shocks using in-situ solar wind plasma and field data from multiple
spacecraft, and determine the relationship between shock parameters and properties
of the SEP events. In addition, the speeds of shocks moving out through the
inner heliosphere will be investigated by tracking the frequency drifts of the
radio emissions that they produce. A particular aim is to better characterize
the speeds of CME-driven shocks near the Sun since, at present, various assumptions
are made by modelers of this important parameter. We will also investigate the
properties of the earliest-arriving particles in order to understand more fully
the production of the highest energy particles that are seen early in such events,
and the influence of factors such as magnetic connection to the solar event,
solar wind structures, and interplanetary particle scattering. In the process,
we will investigate whether or not all the particles in so-called ¿gradual
events¿ are indeed accelerated at CME-driven shocks. These studies will
build on previous work using more limited 1 AU observations in which we have
determined the large-scale structure of interplanetary shocks and how they evolve
as they propagate out from the Sun.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Angelos Vourlidas/Naval Research Laboratory
Title: Search for Shocks Ahead of LASCO CMEs
Abstract:
We propose a research plan designed to contribute to the first of the Focused
Science targets identified in the LWS TR&T program: Shock acceleration of
solar energetic particles by interplanetary Coronal Mass Ejections We will attack
a fundamental component of this problem; namely, the formation and evolution
of CME-induced shocks using a combination of observations, MHD models and analysis
tools. Our goal is to provide a clear understanding of the shock structure in
white light coronagraph images. Our objectives are: (1) to establish whether
CME-driven shocks are detectable in white light coronagraph images, (2) to derive
methods to reliably identify these shocks, and (3) to provide tools for extracting
the physical parameters of the shock for inputs to particle acceleration models.
We will also attempt to compile metrics and/or rules for the easy identification
of the shocks for operational applications. Our analysis will be based on calibrated
white light images from the SOHO/LASCO C2 and C3 coronagraphs. To achieve our
objectives, we will use the high dynamic range and fidelity of calibrated LASCO
images to search for faint emissions/fronts ahead of fast CMEs. We will then
use two new tools, raytrace and magnetosonic speed maps, to identify and measure
the physical parameters across the shocks. We will also use synthetic white
light maps from recent 3D MHD models to guide us in the interpretation of the
various white light features and to investigate the expected visibility/morphology
of the shock under varying viewing angles This work and its potential applications
relate directly to the new vision of NASA as it applies to both human and robotic
exploration. Knowledge of the shock conditions in the corona/heliosphere and
in extension of the likelihood of SEP events will be crucial ¿extending
human presence across the Solar System¿ (a National Objective) and in
particular for successfully conducting Lunar and Martian manned expeditions
(NASA Objectives). Our proposal relates directly to the NASA Objective of ''exploring
the Sun-Earth system to understand the Sun and its effects on Earth, the Solar
System, and the space environmental conditions that will be experienced by human
explorers, and demonstrate technologies that can improve future operational
Earth observation systems''. Our work also contributes to increased understanding
of CME and coronal physics through the better determination of density profiles
in CMEs, shocks and the extended corona, and to better models of the CME phenomenon
through the validation of such codes. In that sense, our work contributes to
the objectives of the Solar and Heliospheric Physics program.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Stephen White/University of Maryland
Title: The Green Bank Solar Radio Burst Spectrometer: A Resource for LWS Studies
Abstract:
We propose to make available high quality dynamic spectra of solar radio bursts
to the LWS community from the Green Bank Solar Radio Burst Spectrometer (GBSRBS),
and to carry out science studies of the connection between radio bursts and
space weather phenomena using these data. GBSRBS will operate from 14 to 1000
MHz in the radio-quiet zone around Green Bank, WVa, with 1 second time resolution
and excellent spectral resolution. The site is particularly important for low
frequency studies, close to the ionospheric cutoff and the upper limit of the
WIND/WAVES and STEREO/SWAVES instruments, because of the very low interference
environment allowing us to see phenomena undetectable from other sites. GBSRBS
will greatly enhance studies of solar radio bursts and their connection to events
that impact the Earth, including coronal mass ejections, flares and acceleration
of solar energetic particles. GBSRBS's wide frequency range and extension down
to 14 MHz is particularly valuable for providing a continuous connection between
phenomena in the low corona and the phenomena seen by the radio detectors on
the WIND and STEREO satellites. This proposal is for support of the data archive
and software development to make the data freely available to the community,
as well as science studies carried out with the data. This project fits into
both the Tools and Individual investigation programs.
Living
With a Star TR&T Program
NNH05ZDA001N
PI:
Simon Wing/The Johns Hopkins University
Title: Plasma Sheet Ion Properties, Sources, and Transport for Different Solar
Wind, Geomagnetic, and Solar Cycle Conditions
Abstract:
Overall Objectives: We have developed a technique for inferring plasma sheet
ion density (n), temperature (T), and pressure (p) from ionospheric observations.
Using this method and DMSP data, we were able to create 2D images of plasma
sheet n, T, and p, which show that the plasma sheet is colder and denser during
periods of northward IMF than southward IMF. This proposal outlines a study
to (1) complement our remote sensing technique with in situ measurements; (2)
construct 2D/3D plasma sheet n, T, and p profiles as functions of plasma sheet
location, geomagnetic activity, solar wind conditions, and solar cycle; (3)
investigate the roles of reconnection, Kelvin-Helmholtz instability, and kinetic
Alfven waves in transporting magnetosheath particles to plasma sheet; (4) the
causes of the dawn-dusk asymmetry in the plasma sheet flanks; (5) ion and electron
heating; (6) electron dynamics; and (7) plasma sheet injection into the inner
magnetosphere and radiation belt/ring current. Research Plan: To carry out our
proposed study, we will use ionospheric and in situ observations as well as
2D simulations that include full ion and electron dynamics and non-MHD processes.
We will construct 2D plasma sheet profiles of location, geomagnetic activity,
solar wind conditions, and solar cycle using DMSP and in situ observations for
almost two solar cycles. We will also link an inner magnetospheric model with
plasma sheet profiles. We will pool NASA Geospace SR&T, NASA LWS TR&T,
and non-NASA resources. A team member, Jay Johnson, has just received a Geospace
SR&T grant to carry out electromagnetic simulations to investigate magnetosheath
particle transport across the magnetopause boundary. Another team member Mei-Ching
Fok will link her radiation belt/ring current model with the proposed plasma
sheet profiles. The proposed project can stand alone, but it will achieve greater
goals if done in coordination with simulations. Rather than comparing observations
with fortuitous published simulation/modeling results, we will actually be able
to design joint observation-simulation studies. Relevance to NASA LWS TR&T
Program: The proposed efforts directly address the topics of interest to the
2005 NASA LWS TR&T Focused Science Topic C (T3C) that solicits ''investigations
that predict and quantify: (1) the amount of solar wind plasma entering the
magnetosphere as a function of location on the magnetopause; (2) the processes
by which plasma is transported from the magnetopause into the magnetosphere
to form the plasma sheet; and (3) the mechanisms by which plasma is injected
into the inner magnetosphere for different solar wind, geomagnetic, and solar
cycle conditions.'' [ROSES 2005 - A.21]. We will disseminate all of our research
results at AGU sponsored meetings and journals as they become available. Moreover,
we will attend Focused Science Topics team meetings where the PI and the Co-Is
will present our results and participate in the discussions.