Living With A Star Targeted Research and Technology
Abstracts of
awarded proposals.
(NRA-03-OSS-01-LWS)
Below are the abstracts of proposals awarded funding for the
Living With A Star Targeted Research and Technology Program. Principal
Investigator (PI) name, institution, and proposal title are also included.
Charles Arge / University of Colorado at Boulder
Short-Term Time
Evolution of Coronal Holes and Their Impact on the Solar Wind at
1AU
Project Summary: Coronal holes are the source of high-speed
solar wind streams, and possibly of slow--speed streams, and thus play an
important role in the nature and structure of the solar wind/heliosphere. Over
the last decade, significant progress has been made in our ability to predict
ambient solar wind conditions days in advance using a number of different
models that vary widely in their sophistication (e.g., MHD and Potential Field
Source Surface Models) but all of which are driven by photospheric field
synoptic maps. These ambient solar models are not expected to and generally do
not work well during periods of transient wind. However, a very recent
comprehensive study by Arge et al. has shown that significant discrepancies
often occur between model predictions and observations after transient wind
has completed its passage past Earth and the observed solar wind has returned
to ambient/background conditions (i.e., when the model is expected to resume
performing well). Such discrepancies can persist for 2 to 3 days after the
passage of the transient. To understand the origin of these differences, we
will use coronal observations at time of CMEs to study variations in the
pattern of coronal holes at the Sun. Our goal is to investigate if short-term
changes in coronal holes (probably not visible in photospheric field synoptic
maps) can be responsible for the changes seen at 1AU.
Sunanda Basu / Center for Space Physics, Boston
University
Studies of Ionospheric Plasma Structuring at Low Latitudes from
Space and Ground, their Modeling and Relationships to
Scintillations
This research is a direct response to the near term
emphasis in the announcement of opportunity for LWS TR & T on geophysical
conditions favoring the development of low- and mid-latitude scintillations in
the Earth's ionosphere. The exciting dataset from the GUVI sensor on the TIMED
mission has opened up opportunities for global studies not hitherto possible.
We utilize this dataset and couple it with models to isolate the drivers of
equatorial electrodynamics. We will validate the results against electric
field measurements by the Jicamarca radar (when available), a dense network of
ground-based GPS receivers yielding total electron content and conjugate
ionospheric imagers, all in the South American longitude sector. We have
adopted a two-tiered modeling approach to drive the NRL bubble model with
large-scale drivers derived from the SAMI3 model of the background ionosphere,
constrained by the GUVI images at 135.6 nm. We will complete the loop by
comparing the output of the bubble model against global scintillation
measurements obtained from the AFRL scintillation network SCINDA. This will
allow us to develop a metric for scintillation occurrence on a global scale at
low latitudes. Our comprehensive approach will provide a better understanding
of the characteristics of ionospheric plasma structures, and will lead to an
improvement of the metric, thereby advancing our capability to predict the
occurrence of scintillations. The societal benefit of such improved capability
to predict ionospheric space weather will be considerable. This is because of
the deleterious effects of large and small-scale plasma structures on
satellite communication and GPS-based navigation systems. We will investigate
how these effects are controlled by the solar influence on the background
ionization density as well as, solar transients that lead to geomagnetic
storms and penetration of high latitude electric fields into low latitudes.
Such electric fields profoundly modify the ionospheric plasma processes in
space and time. Thus the dual goals of this comprehensive research effort,
better understanding of ionospheric plasma structuring and estimating impacts
on technological systems, are what makes this project uniquely suited to
NASA's LWS Program.
Robert Benson / Goddard Space Flight Center
Solar-Cycle and
Short-Term Variations of Topside Ionospheric Electron-Density
Profiles
The overall objective is to determine the dependence of
the mid-latitude topside ionospheric electron-density (Ne) altitude
distributions on long-term solar-cycle variations and short-term solar-wind
and magnetic disturbances. The main focus will be on Ne profiles from the
height of the ionospheric Ne maximum to ~ 3,000 km as deduced from ISIS
(International Satellites for Ionospheric Studies) topside-sounder data. These
data, obtained over an 18-year time interval, will be used to investigate
secular changes in the topside Ne profiles, which reflect altitude changes in
plasma temperature and ion composition, over more than a solar cycle. In
addition to providing average distributions the data, which extend from the O+
dominated high-altitude F region to the H+ dominated plasmasphere, provide a
unique framework for delineating the altitude dependence of mid-latitude
ionospheric structures associated with the plasmapause, plasmaspheric tails
and Storm Enhanced Densities. The approach will be to (1) extend the digital
ionospheric topside-sounder data base at the National Space Science Data
Center (NSSDC) back to the solar minimum of 1965, (2) process all digital
topside-sounder ionograms recently made available at the NSSDC into topside Ne
profiles (making them also available to the scientific community via the
NSSDC) and (3) relate latitude/local-time changes in the average mid-latitude
topside Ne profile characteristics, particularly scale-height variations, to
changes in solar-activity indices, solar-wind parameters and geomagnetic
indices. Our objective supports the Living With a Star (LWS) goal "to develop
the scientific understanding … to effectively address those aspects of the
connected Sun-Earth system that affect life and society" in that a knowledge
of mid-latitude topside ionospheric structures and their dependence on solar
conditions is needed to mitigate the ionospheric impacts on advanced
technological systems, such as GPS positioning, where the ionospheric effects
on trans-ionospheric radio propagation is often the limiting factor on overall
system performance. It supports the LWS Targeted Research and Technology broad
objective #1 by performing "…the analysis and interpretation of past and
present data to identify and understand the basic physical processes
underlying the Sun-Earth system …" and also one of the research topics listed
of high current interest, namely, "The effects of varying solar EUV radiation
on the Earth's ionosphere and atmosphere."
Joachim Birn / Los Alamos National Laboratory
Modeling Coronal
Structures and Dynamics
Coronal mass ejections (CMEs) are a
principal link in the chain of events that affect space weather and the
Earth's plasma environment and hence play a central part in pursuing the
objectives of NASA's Living With a Star (LWS) program. A crucial goal in the
study of CMEs is understanding the evolution of the coronal magnetic field
prior to an eruption. This goal requires the determination of the initial and
boundary conditions that lead to an eruption and the identification of
observable features associated with these conditions. Our proposed work
consists of three major tasks. Task 1 is the derivation of suitable initial
states. Since the pre-eruption state or states are not well known, a number of
states need to be developed and tested. Here we propose to use an established
analytical method, as well as a numerical method, to derive both force-free
and non-force-free states and to determine their equilibrium properties. Some
of these models will contain a twisted flux rope, connected to the photosphere
and anchored in the corona by an overlying arcade, and others will include a
helmet streamer configuration above the flux rope. These models will also be
supplemented by several loop-type models previously suggested in the
literature. Task 2 is the test of the stability and of the subsequent dynamic
evolution of the various equilibrium configurations, using MHD simulations. Of
particular interest are the potential development of current sheets, their
breakup by magnetic reconnection, the development of flare loops and flare
ribbons, and the identification of observable signatures that characterize the
unstable configurations. Again, this requires the possible existence or
formation of non-force-free configurations. The final task, 3, is to determine
the energetic particles spectrum produced by reconnection as a function of
space and time during the course of an eruption . In this work we will trace
both ions and electrons as they propagate within the electric and magnetic
field generated in the various MHD simulations. This test-particle approach
will provide specific predictions for each model as to the type and
distribution of energetic particles that it should produce. Such predictions
can then be compared with energetic particle distributions that are inferred
from the hard X-ray and g-ray emissions now being observed by the RHESSI
spacecraft. Tasks 2 and 3 will also be supplemented by an investigation into
kinetic aspects of magnetic reconnection, which might affect reconnection
rates and particle acceleration.
Douglas Braun / NorthWest Research Associates, Inc.
Local
Seismology of Solar Dynamics: From MDI to HMI
The Solar Dynamics
Observatory (SDO) is the first major mission in NASA's Living With a Star
Program, and is scheduled for launch in 2008. One of the major science
investigations on board SDO is the Helioseismic and Magnetic Imager (HMI),
designed to understand the structure and dynamics of the Sun's interior,
especially the variation of magnetic activity, from helioseismic analyses. In
this project, we are interested in addressing the following fundamental
questions: 1) What is the nature of supergranulation?, 2) What is the
subsurface nature of meridional circulation and how does it vary with time?,
3) What is the nature of other large-scale flows and how do they correlate
with magnetic activity?, 4) what are the local acoustic properties of the
tachocline and how do they vary with time? and 5) what are the local acoustic
properties of the solar poles and how do they vary with time? To address these
questions, we propose to apply a variety of diagnostic utilities in seismic
holography to existing data from the Michelson Doppler Imager (MDI) with the
goal of preparing for their routine use with data from HMI/SDO. The goals of
this proposed project are designed to further our understanding and predictive
capabilities of the solar magnetic variability that influence life and
technological systems on Earth.
Joan Burkepile / National Center for Atmospheric Research
Data
Environment: Creation of Online Access to the Complete Set of Solar Maximum
Mission (SMM) Coronagraph/Polarimeter Observations
The Solar
Maximum Mission (SMM) Coronagraph/Polarimeter (C/P) was in Earth orbit and
observed the solar corona from February through September of 1980 and from
June, 1984 through November, 1989. The observations were taken in broadband
white light with a field-of-view from approximately 1.8 to 5.0 solar radii.
During these years the SMM C/P instrument recorded over 1300 coronal mass
ejections (CMEs) and observed coronal brightess changes that varied with the
solar cycle. The SMM Mission was originally funded under NASA contract S-04167
which expired approximately one decade ago. A small sample of SMM images are
currently available from HAO via the internet. This small set of images are
scaled and provided for qualitative use only. We propose to provide the SMM
observations in their entirety, to the scientific community and general public
via the internet. This work will involve conversion of the binary data into
fits format, widely used by the astrophysical community, which can be used for
both qualitative and quantitative purposes. The data will be transferred from
exabyte tapes to a newly acquired data storage jukebox accessible to the the
internet by a new SMM web site. This new web site will include basic viewing
and analysis tools to allow users to measure positions and brightnesses in the
corona as well as generating trajectories, densities and masses of CMEs.
Geoffrey Crowley / Southwest Research Institute
LWS: Effect of
EUV and High Latitude Forcing on Thermospheric Densities
Changes in
the density and composition of the neutral atmosphere create variable
satellite drag, adversely affecting our ability to identify and track objects
in space and to predict their re-entry into the atmosphere. We propose to use
new density data from the GRACE, CHAMP and TIMED satellites, together with
solar EUV drivers from TIMED, and various high latitude data to determine the
effects of long and short-term variability of the Sun on the mass density of
the atmosphere between 120 and 600 km altitude. Specifically, we will test our
understanding and modeling of the effects of solar EUV, Joule and particle
heating, and momentum forcing on thermospheric densities in the 120 - 600 km
region. The proposed work will lead to improvements in our ability to
understand and predict satellite drag variations during geomagnetic storms and
during the solar activity cycle. Eventually, this work will lead to 1st
principles models (probably with data assimilation) that describe these
density (and associated composition) effects with accuracy better than 5%. In
turn, the proposed work will lead to better predictions of satellite orbits.
We propose to achieve our goals by answering the following three science
questions: 1) What is the magnitude of thermospheric density changes in
response to variability of the Sun on different temporal scales? 2) How does
density in the upper thermosphere respond to Joule heating? 3) What are the
key drivers of density perturbations in the upper thermosphere?
Giuliana de Toma / National Center for Atmospheric
Research
Short-Term Time Evolution of Coronal Holes and Their Impact on the
Solar Wind at 1AU
Coronal holes are the source of high-speed solar
wind streams, and possibly of slow-speed streams, and thus play an important
role in the nature and structure of the solar wind/heliosphere. Over the last
decade, significant progress has been made in our ability to predict ambient
solar wind conditions days in advance using a number of different models that
vary widely in their sophistication (e.g., MHD and Potential Field Source
Surface Models) but all of which are driven by photospheric magnetic field
synoptic maps. These ambient solar models are not expected to and generally do
not work well during periods of transient wind. However, a very recent
comprehensive study by Arge et al. has shown that significant discrepancies
often occur between model predictions and observations after transient wind
has completed its passage past Earth and the observed solar wind has returned
to ambient/background conditions (i.e., when the model is expected to resume
performing well). Such discrepancies can persist for 2 to 3 days after the
passage of the transient. To understand the origin of these differences, we
will use coronal observations at time of CMEs to study variations in the
pattern of coronal holes at the Sun. Our goal is to investigate if short-term
changes in coronal holes (probably not visible in photospheric field synoptic
maps) can be responsible for the changes seen at 1AU.
Matthew DeLand / Science Systems Applications, Inc.
Creation of a
Composite Solar Ultraviolet Irradiance Data Set
A detailed
knowledge of solar ultraviolet (UV) irradiance is critical to understanding
the Sun-Earth system because of its impact in the terrestrial atmosphere.
Satellite measurements of solar UV irradiance have been made since 1978, and
numerous data sets are available (Nimbus-7 SBUV, SME, NOAA-9 and NOAA-11
SBUV/2, UARS SUSIM and UARS SOLSTICE). However, no single data set covers more
than one 11-year solar cycle. Comparisons between overlapping data sets show
both absolute offsets and time-dependent drifts. These differences need to be
resolved in order to evaluate solar UV variations on longer time scales for
climate studies. This proposal will merge the individual solar UV irradiance
data sets from all available satellite instruments to create a unified
composite UV irradiance data set. The wavelength range is 120-400 nm, which
represents solar radiative input to the Earth's atmosphere from the surface to
the mesosphere. The time period covered by the composite UV data set is
November 1978 to the present, representing more than two complete solar
cycles. Absolute offsets between data sets will be adjusted using comparisons
to recently published reference spectra. Time-dependent differences between
instruments during periods of data overlap will be evaluated using confidence
limits assigned by the respective instrument scientists, as well as irradiance
variations predicted by the Mg II proxy index. The composite irradiance
product will then be created using a weighted combination of the observed
irradiance data. This composite UV data set, in turn, will make it possible to
examine relationships between irradiance and proxy data on multi-decade time
scales. The composite UV irradiance data set will benefit additional areas of
the Living With a Star program. We plan to merge our product with spectral
irradiance data from the recently launched SORCE mission to provide a
continuous irradiance data record for future climate studies. The solar
extreme ultraviolet (EUV) spectral region below 120 nm provides energetic
input for the ionosphere and thermosphere, but has not been measured with
sufficient frequency or wavelength coverage to construct an equivalent
irradiance data set. The composite UV irradiance data set will provide a
comprehensive comparison product for all available EUV data sets, such as SOHO
time series and TIMED SEE irradiances. This data set will also provide an
improved basis for the development of empirical forecast models of solar
activity.
Carsten Denker / New Jersey Institute of Technology
Data
Environment: Data Mining and Visualization Server at Big Bear Solar
Observatory
We are seeking short-term (1 year) support from the
Living with a Star Program (NRA-03-OSS-01-LWS) to enhance the data environment
at Big Bear Solar Observatory (BBSO). We propose to acquire a TByte storage
system with the capability of storing about two years of BBSO data on-line. A
WWW server with multiple CPUs and fast data I/O provides access to the data
bank and tools for data mining and visualization. The BBSO on-line data sets
include: 2k x 2k pixel, 14-bit H-alpha full disk images at a 1-minute cadence,
daily 1k x 1k pixel, 12-bit Ca II K and white-light full disk images, 512 x
512 pixel, 14-bit H-alpha and Ca II K filtergrams from the 25 cm vacuum
refractor with a field-of-view (FOV) of 300 arcsec x 300 arcsec at a 1-minute
cadence, 512 x 512 pixel digital vector magnetograms from the 25 cm vacuum
refractor with a FOV of 300 arcsec x 300 arcsec at a 1-minute cadence for the
longitudinal magnetic field component and 4-minute cadence for the full Stokes
vector, and high-spatial resolution 1k x 1k pixel, 12-bit filtergrams with a
75 arcsec x 75 arcsec at a 1-minute cadence from the 65 cm vacuum reflector
obtained with the real-time image reconstruction system. All data have an
extended SoHO-style filename and header information, which reflect the BBSO
instrument specific characteristics, e.g., high cadence data, calibration
level, spectral scans, etc. Flat-field corrected data is stored in JPEG format
for quick look analysis and the corresponding FITS data (raw data and higher
level data products) can be retrieved through WWW interfaces or simple
scripts. All data analysis software is readily available. Only data storage
limitations prohibited us so far from making all data available, which will no
longer be the case with the proposed system. In the future, we intend to make
higher level data products available such as MPEG movies of user selected
regions of interest in the H-alpha full disk images, daily differential
rotation maps in H-alpha and residual flow maps, and high-spatial resolution
MPEG movies and corresponding horizontal flow maps. BBSO data has been used in
many multi-wavelength studies of solar activity in coordination with NASA's
space-based observatory platforms. One illustrative example are the H-alpha
full disk images used to provide context data and operational information to
the Reuven Ramatay High Energy Solar Spectroscopic Imager (RHESSI). We expect
that the new TerraByte storage system and the fast WWW server for data mining
and visualization will enhance the scientific output of NASA space missions
and provide a valuable resource for the solar and space physics communities in
the context of the Living with a Star program.
George Fisher / University of California Berkeley
A Global MHD
Model of the Solar Interior for Coupled Sun-Earth System
Studies
The primary objective of this proposed project is to
understand how the observed evolution of magnetic fields on the Sun on long
(solar cycle) time scales is related to dynamic processes occuring in the
solar interior, where the Sun's magnetic fields are generated. This will
improve our understanding of the connection between coronal and photospheric
magnetic field topologies, as well as the connections between these fields and
those in the solar interior. The successful achievement of this objective will
allow the development of better predictive models for the transport and
evolution of magnetic fields on the Sun, and a better understanding of the
correct physics to include in solar cycle evolution models. To accomplish
these goals, we will use two 3-D anelastic MHD models, an existing Cartesian
model known as "ANMHD", and a new model in spherical coordinates that is now
being developed, known as "SANMHD", as well as existing coronal models in use
in our group at UCB/SSL. Both anelastic MHD models will be released to
NASA/GSFC's Community Coordinated Modeling Center (CCMC), for general use by
the "Living With a Star" (LWS) and Solar Physics communities. This project
directly supports one of the 2003 LWS research topics of high current
interest, "The magnetic field topology connecting the photosphere to the
corona", as well as the general LWS goal of understanding basic physical
processes governing the Sun-Earth system. Part of our effort will be to study
the connection between the very different physical environments of the corona
and the solar interior, crossing discipline boundaries.
Peter Foukal / Heliophysics, Inc.
Facular Studies to Improve
Reconstruction and Prediction of Solar Irradiance
Our proposed
study has three aims: 1.The recent balloon flight of the Solar Bolometric
Imager (SBI) provides the first wide band images of the photosphere, creating
an important opportunity to improve models of total irradiance variation.We
propose to use SBI measurements of facular and spot contrast, together with
ground-based and MDI magnetograms and photometry, to determine whether
photospheric magnetic structures can account for rotational and 11-yr
irradiance variation, or whether other mechanisms such as convective stirring
might contribute. 2.Our recent reconstruction from archival CaK images
indicates that solar total and UV irradiances differ significantly between
1915-1999 - a finding of key interest to climate modellers and aeronomers.We
propose here to extend this reconstruction by using the white light facular
area record compiled at Royal Greenwich Observatory between 1874-1976.Our aim
is to compare the relative correlations with climate of the reconstructed UV
and total irradiances, throughout the period of global warming,in order to
assess their relative importance in driving recent climate. 3.The ratio of
spot and facular areas early in a spot cycle has been shown to provide a good
predictor of sunspot cycle amplitude in the 1874-1976 RGO data. It is also a
key factor determining 11-yr irradiance variation.Our aim is to measure this
ratio on WL images obtained at the onsets of cycles 22-23, to determine the
more recent "skill" of this predictor, use it predict activity and irradiance
levels in the forthcoming cycle 24, and study its implications for future
non-axisymmetric,solar dynamo modelling.
Reiner Friedel / Los Alamos National Laboratory
Quantifying
Energetic Electron Precipitation from the Radiation Belts and their Relation
to Storm-Time Dynamics
One of the major obstacles to understanding
dynamic inner magnetospheric dynamics of energetic electrons is our limited
understanding of their dynamic loss processes. The recent LWS Geospace Mission
Definition Team Report states: ``To be able to specify and predict changes in
the radiation belt populations requires measurement and a quantitative
understanding of the dominant loss processes''. Losses are the most dominant
feature during the onset-phase of geomagnetic storms, and lead to increased
fluxes at LEO orbit which is occupied by a large amount of space hardware,
including the International Space Station. Energetic electron precipitation
increases during active times, but it is not known whether this increase is
due to increased loss rates or simply an overall increase in the radiation
belt population. Several of the wave particle interaction processes that may
be responsible for both losses and acceleration of relativistic electrons are
thought to exhibit strong local time preferences - dawn for whistler chorus,
afternoon to dusk for EMIC waves, and are active during different phases of a
geomagnetic storm. We plan to test these and other hypotheses directly. We
expect to answer the following specific scientific questions, which are
directly in line with the ``questions critical for the quantitative
understanding of the role of electron loss'' as stated in the LWS Geospace
Mission Definition Team Report: 1.Can we quantify and document a relative
increase of particle losses during active times? 2. Is there a local time
and/or radial dependence to enhanced particle losses? Do these dependencies
agree with theoretical predictions? 3. What is the relation of these losses
with regard to the onset, main phase and recovery phase of geomagnetic storms?
We intend here to use low altitude data from four recent NOAA POES spacecraft
together with (near-)equatorial data from several satellite missions - from
POLAR (one spacecraft, L=3--8), from HEO (2 spacecraft, L=2--4), LANL GPS (4
spacecraft, L=4--5.5) and LANL GEO (6 spacecraft, L=6.2--7.2) to investigate
the location and strength of energetic electron loss processes during
geomagnetically active times. POLAR, the DOE/DOD geosynchronous and GPS
missions, HEO and NOAA spacecraft are all currently operational. They form an
inner magnetospheric constellation and are an ideal testbed for future
constellation-type missions such as envisioned by the Living with a Star
Program. The resources of this existing constellation can be used by the
Living with a Star Program at no operational cost.
David Fritts / NorthWest Research Associates, Inc.
Experimental
and Modeling Studies of Potential Gravity Wave Seeding of Plasma Dynamics at
Equatorial Latitudes
Atmospheric gravity waves (GWs) have been
suggested for many years to play a role in seeding Rayleigh-Taylor
instability, equatorial spread-F (ESF), and plasma bubbles penetrating to high
altitudes. But despite numerous modeling studies and measurements suggesting
such a role, no definitive experiments have occurred. Our goal is to combine
comprehensive ground-based optical and radar instrumentation, in situ and
nadir imaging satellite observations, and modeling of GWs arising from
tropical convection and their propagation to high altitudes to document such
seeding, if it occurs, and to assess the geophysical conditions favoring
seeding and controlling GW influences on ESF and bubble statistics and
morphology. Our research team represents a collaboration between three
research groups and two satellite PIs who will jointly perform two measurement
programs in Brazil coordinated with TIMED and ROCSAT-1 or C/NOFS. Our method
will be to observe GWs arising from deep convection in central and eastern
Brazil as they propagate through the mesopause and into the thermosphere, to
measure the responses in the bottomside F layer, and to correlate these
responses with satellite and radar observations of ESF and bubble structures
at greater altitudes. Modeling efforts will assess and confirm the links
between GW sources and ionospheric effects.
Peter Gallagher / GSFC
Fields, Fractals, and Flares:
Understanding Magnetic Complexity in Solar Active Regions
Solar
active regions are the source of many energetic and geo-effective events such
as solar flares and coronal mass ejections (CMEs). Understanding how these
complex source regions evolve and produce these events is of fundamental
importance, not only to solar physics, but also to the demands of space
weather forecasting. We propose to investigate the physical properties of
active region magnetic fields using fractal-, gradient-, neutral line-,
emerging flux-, and wavelet-based techniques, and to correlate them with solar
activity. This will form the basis of a real-time online database of
spaceweather-relavent data products. This timely study represents a
non-phenomenological approach to describing and understanding active region
evolution and the conditions that result in energy release. The results of
this study will provide an important knowledge base for future missions within
the Living With a Star (LWS) program, such as the Solar Dynamics Observatory
(SDO), and the development of online environments such as the Virtual Solar
Observatory (VSO).
Trevor Garner / Applied Research Laboratories, University of Texas
at Austin
An Investigation of Magnetosphere-Ionosphere-Coupling Through the
Subauroral Electric Field with the Development of a Parameterized Subauroral
Electric Field Model
LWS seeks to better understand the coupling of
the magnetosphere, ionosphere and thermosphere (MIT). Ideally, studies of the
storm-time coupling would involve completely coupled models of these two
systems. However, this coupling is often computationally prohibitive, and
theoretical studies of one region typically employ a proxy model for the other
region. The proposed work will investigate the role of the subauroral electric
field in MIT coupling. In particular, this work will examine the how changes
in the MIT system caused by the subauroral electric field feed back into the
electric field. The Rice Convention Model (RCM) and the
Thermosphere-Ionosphere-Mesosphere-Electrodynamics General Circulation Model
(TIME-GCM) will be pseudo-coupled in order to investigate these feedback
mechanisms. Pseudo-coupling is the process of using outputs from one model as
inputs to the other model while running each model as a separate code. The RCM
has successfully modeled subauroral polarization streams (SAPS), strong
shielding electric fields, penetration electric fields, and overshielding.
These electric fields will drive ionospheric motion and heat the thermosphere,
which will significantly alter the ionospheric conductance. This is the main
feedback mechanism to be studied in this proposal, but not the only one. The
coupled inputs to be examined here are the global ionospheric conductance, the
location of the auroral boundaries, the neutral wind-generated electric field,
and the Region-2 generated electric field. By incrementally adding coupled
inputs, the effect of each input will be determined independently. A series of
test runs will be conducted to investigate the general behavior of the
coupling. In addition, a parameterized subauroral electric field (PaSEF) model
will be developed from the results of the pseudo-coupled runs. It is hoped
that this PaSEF will replace the Volland-Stern model in general community
usage.
Philip Goode / New Jersey Institute of Technology
Earthshine:
Measurements and Simulations of the Earth's Reflectance
It is
important to know the Sun's role in the apparent on-going global change in the
Earth's climate. In this effort, one needs precise, globally integrated
measures of relevant quantities extending over many years. To that end, we
propose to continue observations, both photometrically and spectrally, and
interpretation of the earthshine, which is sunlight reflected from the Earth
and then retro-reflected from the Moon back to the earth. Proposed Scientific
Objectives in the Earthshine Project: 1) We propose to continue our
photometric observations of the earthshine from Big Bear Solar Observatory
(BBSO), while expanding these observations to a global network. These data are
critical in our efforts to determine the relationship between a varying
terrestrial albedo and a variable Sun. For this, we need a precise
determination of the reflection of the Earth in all directions, the Bond
albedo. From a single site, we can reliably determine the Bond albedo as an
annual average. The global network is essential here because our modeling has
convinced us that we can determine precise monthly averages with it. Monthly
averages enable us to make more precise comparisons with climate parameters
and various measures of solar activity from sunspot number to galactic cosmic
ray flux at the Earth. 2) We propose to improve our simulations to include
more sophisticated models of the terrestrial scenes, while including more
parameters for the cloud cover by using data from the International Satellite
Cloud Climatology Project (ISCCP). An improved treatment of the clouds is
required to improve our simulations. 3) We propose to sharpen and exploit the
connection of the earthshine observations to cloud cover data from ISCCP,
which will significantly improve our understanding of cloud cover data and aid
our efforts to determine the connection between the solar output and the net
sunlight reaching us on Earth (solar irradiance plus any indirect effects of
irradiance and/or solar magnetism on the Earth's reflectance) . The ultimate
goal is to learn the origin of the terrestrial signature of the solar cycle,
and the usefulness of the sunspot number as a proxy for the net sunlight
reaching Earth. 4) Finally, we propose to perform and interpret spectral
observations of the earthshine in the visible and near infrared to study the
variation of the atmosphere's greenhouse gas (water, carbon dioxide, methane,
?) content to understand the physical origin of the Earth's radiation budget
variability. Here we also will probe the wavelength dependence of the Earth's
albedo. In the near infrared where some greenhouse gasses have a strong
signature, we propose to compare our observations with modelled spectra to
reveal essential information about the abundance of greenhouse species in the
atmosphere, providing temperatures, optical path lengths and column densities
for each of them. These parameters are otherwise difficult to determine as a
global average, in particular for water vapor, which is not a well-mixed gas.
Further, we propose to monitor changes in the abundances of those species and
the radiative properties of the atmosphere. These Earth-as-a-star observations
can also provide complementary information to future NASA missions searching
for extra-solar planets. In "Astrophysics in 2001'' by Trimble and Aschwanden
(2002), the authors remarked about our earthshine observations saying that
this "type of lunar-geo-solar observations is one of the rare
interdisciplinary examples that naturally fulfills all requirements for NASA
funding, for originality of astronomical research to direct benefits for
humankind''.
Natchimuthuk Gopalswamy / Goddard Space Flight Center
Coronal
Mass Ejection Data Products for LWS Science
Data products based on
coronal mass ejection measurements are currently made available on line
(cdaw.gsfc.nasa.gov). In order to facilitate and enhance the data analysis and
modeling activities geared towards achieving the goals of the Living with a
Star program, the data base needs to be continually updated and maintained. We
propose to enhance the CDAW data center with new value-added products such as
mass of the CMEs and online computing facilities for easy accessibility and
utility for modelers. The data base will also support the development of
automatic CME detection schemes, which will become inevitable when LWS
missions start collecting data The data base will also be used the develop the
understanding of CME-rate variability over the current solar cycle (23).
Janet Green / LASP, University of Colorado
Relativistic Electrons
in the Outer Radiation Belt: Understanding How Losses Contribute to Flux
Variability During Storms
Recent studies show that storms can cause
the outer radiation belt electron flux levels to increase or decrease
suggesting that both acceleration and loss are enhanced and either process may
dominate. The purpose of the proposed research is to understand how losses
contribute to the variation of the outer radiation belt electron flux during
storms. Several loss mechanisms have been proposed but not confirmed partly
because of difficulties even identifying true loss that is often obscured by
flux changes due to adiabatic electron motion. We propose to first identify
times, locations, and amounts of true electron loss during storms by examining
electron phase space density expressed as a function of the adiabatic
invariants which highlights true irreversible electron loss. Secondly, we will
examine whether precipitation to the atmosphere contributes to electron loss
during storms by comparing the time, location, and amount of true loss to
measured precipitation. Lastly, we will determine whether magnetopause
encounters contribute to electron loss during storms by comparing the time and
location of observed loss to modeled magnetopause encounters and by comparing
electron and proton phase space density that should both be similarly affected
by magnetopause encounters.
Donald Gurnett / The University of Iowa
Data Environment Proposal
for Archiving Cluster Wideband Plasma Wave Data for the International Living
With a Star Program
The key objective of this data environment
proposal is to archive high resolution spectrograms of all Cluster Wideband
plasma wave data obtained to date. We propose to provide these data, along
with useful documentation, to the Cluster Active Archive. The Cluster Active
Archive is the repository for the high resolution data obtained from all of
the Cluster instruments for the life of the mission. This repository is being
constructed by the European Space Agency and will be part of that agency's
contribution to the International Living With a Star programme. The Wideband
data will be delivered to the Cluster Active Archive via either electronic
link or on DVDs. A part of the proposed effort also involves the preparation
of formal interface documents between the Cluster Active Archive and the WBD
instrument Principal Investigator as to delivery products and schedules. The
WBD data, in conjunction with the data from all of the other Cluster
instruments, can then be obtained through the Cluster Active Archive to
perform scientific research relevant to the Living With a Star program. We
briefly describe some of the studies that can be carried out using these data,
including (but not limited to) studies of the motion of the bow shock,
reconnection at the magnetopause, the role of auroral kilometric radiation in
substorms, and the significance of the intense storm-time chorus waves.
John Harvey / National Solar Observatory
Characterizing the Solar
Vector Magnetic Field with Application to Space Weather
Forecasting
We propose to acquire and use unique, new magnetic
observations to characterize the physical properties and evolution of solar
vector magnetic fields and to use this new understanding to help develop tools
to forecast storms in the Sun-Earth system. A powerful new instrument called
SOLIS provides the first regular, full-disk measurements of the solar vector
magnetic field. It also measures the line-of-sight component of the
photospheric and chromospheric magnetic fields with an unprecedented
combination of sensitivity, freedom from instrumental polarization, high
accuracy, and good temporal and spatial resolution. Although many aspects of
the vector magnetic field will be examined, particular attention will be
directed to spatial scales larger than a typical active region and to high
latitude properties of the vector field. It is likely that these regions
contain important information about the formation and evolution of open fields
connected to the heliosphere and the magnetic structures that spawn coronal
mass ejections. We will provide vector boundary conditions for models of the
corona and heliosphere that have heretofore been forced to depend on only one
component of the magnetic field. This will enable more accurate MHD coronal
modeling. Vector observations of active regions will be used to calculate the
fluxes of magnetic free energy and magnetic helicity. Variations of these
fluxes will be evaluated as flare forecasting tools. We will study the
structure and time variations of fields associated with filaments and large
bipolar coronal streamers in order to test physical models of these phenomena
and also to seek properties of use in building coronal mass ejection
forecasting tools. We propose to operate SOLIS for daily periods up to two
times longer than will otherwise be possible, to better support operating and
forthcoming NASA missions such as SOHO, TRACE, RHESSI, STEREO, Solar-B and
SDO.
John Harvey / National Solar Observatory
Translation and
Correction of NSO Kitt Peak Vacuum Telescope Solar Synoptic Data
A
30-year record of daily full-disk observations of the solar magnetic field and
helium chromosphere from the National Solar Observatory ended on September 21,
2003. These data have been widely used in support of NASA missions and in
~1000 scientific research papers and theses. The data suffer from various
calibration problems and artifacts that can be corrected. The data and derived
products are scattered across various media and are not readily accessible by
users. We propose to correct known calibration problems, remove artifacts and
store the data in a homogeneous environment that is easily accessible by users
with widely available tools. We also propose to recalculate many secondary
data products, including synoptic maps of several types. This restored data
set will allow ongoing and forthcoming NASA solar missions to be placed in a
longer context of varying solar magnetic conditions. The data will also be
available for continuing research studies of the long-term behavior of the
solar magnetic field and for studies of particular past periods of special
interest.
Umran Inan / Stanford University
A Global Model of the Effects of
ELF/VLF Chorus Emissions on Energetic Radiation Belt Electrons
We
propose to construct a global model of the distribution of ELF/VLF chorus
emissions in space and time during and following periods of magnetic
disturbance. This model will be used to determine if the energization of
radiation belt electrons to MeV energies is a result of interactions between
the chorus and the electrons. We will use a non-linear test particle resonant
interaction model calculation to determine the change in energy and pitch
angle of resonant energetic electrons due to typical ELF/VLF chorus elements,
including nonlinear effects due to the high intensity of the wave, the
coherent nature of the waves, their frequency-time variation, and wave normal
changes due to propagation effects. The chorus element will be characterized
at the generation region using already analyzed POLAR and CLUSTER data. The
characteristics of the waves after they leave the source region will be
determined using raytracing. Using these results in conjunction with new
findings concerning chorus occurrence and distribution in space and time, the
global chorus-driven energization rates and pitch angle scattering rates will
be calculated and compared with measurements to determine whether chorus is
the dominant mechanism in the rapid, storm-time energization of electrons in
the Earth's outer radiation belt.
Philip Isenberg / University of New Hampshire
A Kinetic Model for
Preferential Acceleration and Heating of Solar Wind Heavy Ions
In
the previous funding period, we developed our "kinetic shell" model of the
maximal resonant cyclotron interaction for the energization of coronal hole
protons by parallel-propagating ion cyclotron waves. Preliminary
dispersionless results were encouraging, and we expected to obtain the
evolution of both the fast wind proton distribution function and the wave
spectra as functions of heliocentric radius in a coronal hole. However, we
found that the addition of wave dispersion drastically limited the amount of
wave energy which could be absorbed by the protons, and the perpendicular
heating required to drive the fast wind could not be produced by this
interaction. We concluded that some other energization process must be
responsible for the bulk heating and acceleration of the protons. The
situation is very different for heavy ions since, in contrast to protons, they
can resonate with both sunward- and antisunward-propagating waves
simultaneously. This capability results in second-order Fermi acceleration of
the heavy ions, heating them primarily perpendicular to the magnetic field, in
a manner not accessible to protons. We propose to model the radial evolution
of a heavy ion distributions under the action of this Fermi acceleration along
with the ion response to the standard gravitational and electromagnetic forces
in the coronal hole. We will start with trace populations, like O5+ and Mg9+,
seeking to match the UVCS observations of these species. We will determine the
required intensities of counter-propagating resonant waves and compare these
results to recent theories of Alfven wave reflection and turbulent processes
in coronal holes. We will then consider the case of alpha particles, whose
bulk properties will affect the dispersion relation of the waves, leading to a
more complicated interaction. Our goal will be to obtain a detailed kinetic
description of the coronal hole heavy ion distributions, explaining the source
of the preferential acceleration and heating of these ions which is
consistently observed in the fast solar wind. This proposal seeks to address
the Living With a Star RFA's under Goal II, SEC Theme, 1(a) and 2(a), which
additionally support Goal I, SEC Theme 1(a).
Shrikanth Kanekal / Catholic University of America
Comprehensive
Survey of Magnetospheric Relativistic Electron Dynamics over Complete Solar
Cycle
Many geomagnetic storms result in the energization of
electrons in the inner magnetosphere to relativistic energies with electron
fluxes increasing by several orders of magnitude. It is well known that high
solar wind velocity and southward component of the interplanetary magnetic
field are the fundamental causative agents. Physical models of energization
are many and invoke processes ranging from purely-adiabatic radial diffusion
to in-situ acceleration by both stochastic and resonant wave-particle
interactions. It is unclear under what circumstances a particular process or
processes may be the dominant mechanism. This remains a major open scientific
question in magnetospheric physics. It is also important from a space weather
perspective since relativistic electrons are implicated in spacecraft
anomalies and failures. The research proposed here will be to systematically
survey electron energization over a complete solar cycle. The research
undertaken will explore the internal magnetospheric dynamics and the
dependence of electron energization upon external causative agents. We will
measure characteristics of electron acceleration such as the spatial extent,
temporal evolution of energy spectra, and acceleration, decay and
isotropization times. We will compare relativistic electron events that occurr
during different phases of a solar cycle. It is well known that during the
declining and ascending phases of a solar cycle the magnetosphere is driven by
recurrent high speed solar wind streams (HSS) and Coronal mass ejections (CME)
respectively. The proposed work will also study of the relationship between
the characteristics of relativistic electron enhancements and geomagnetic
storm parameters. We will investigate the correlations between geomagnetic
storm strength and duration, and the magnitude and extent of the relativistic
electron fluxes. The uniqueness of our study comes from our use of data
collected by the same suite of instruments over an entire solar cycle. These
instruments provide a complete coverage of the entire outer zone over a wide
range of energies. This research will be based upon data collected from PET,
LICA and HILT sensors onboard SAMPEX and the HIST sensor onboard Polar. Both
spacecraft provide energetic electron data over a wide energy and L-shell
range. SAMPEX sensors cover the time periods starting from Aug 1992 to present
and Polar from March 1996 to present. The use of high quality data collected
from the same sensors over a long period of time reduces uncertainties in
comparing different events. Interplanetary data will be obtained from sensors
onboard ACE, Wind and other spacecraft. This study will provide valuable
observational constraints on the various physical models of electron
acceleration in the inner magnetosphere. Our results will also be a catalog of
the properties of electron enhancement events over a complete solar cycle
which will be highly useful in space weather studies.
Ramona Kessel / Goddard Space Flight Center
Multi-satellite
Magnetopause Data Environment
The primary objective of this
proposal is to bring online and make web-accessible a database of magnetopause
crossings comprised of satellites spanning more than 3 decades and nearly 3
solar cycles. The current proposal is comprised of legacy data sets from the
1960's, 1970's, 1980's, and 1990's, but the design of the database will easily
allow the addition of later data sets. Some of our lists of magnetopause
crossings exist only as paper copies or on old magnetic tape and could be
lost. Some lists are available through the internet but are not widely known
or not generally available. We intend to join all of these lists into one
interface that will be featured on the main NSSDC Space Physics web page. The
final list will contain crossing times, locations and solar wind parameters
when available. The new magnetopause database will be joined with a recent
web-accessible bow shock database with data from 1974 to 2002, and will
inherit all of the latter's capabilities. The multi-satellite magnetopause
database proposed here will significantly enhance long term and global science
studies. LWS is particularly interested in quantifying the behavior of the
physics, dynamics, and behavior of the Sun-Earth system over the 11-year solar
cycle and the magnetopause database will provide 3 solar cycles worth of data.
Magnetopause global shape and position have been modeled extensively but never
with such a complete database. The database can also aid in finding crossings
of interest such as those under extreme solar wind conditions. Multi-satellite
studies are essential to determine motion of the magnetopause or to resolve
waves such as those associated with the Kelvin-Helmholtz instability. The
database proposed here will enable these studies. This proposal also responds
to two of the science objectives and research focus areas of the Sun-Earth
Connection theme of OSS: Goal II SEC RFA 1(c) and Goal I SEC RFA 1(c). The
multi-satellite magnetopause database will span more than 3 solar cycles and
will facilitate studies within a particular solar cycle as well as across
solar cycles. The magnetopause is the outer boundary of the Earth's internal
magnetic field and is a critical transition region for transferring solar wind
mass, momentum and energy into the magnetosphere and driving space climate.
Joseph King / QSS Group, Inc.
Creation of High Resolution OMNI
and Other Merged ACE, Wind and IMP 8 Data Sets, and Solar Wind
Cross-Correlations
This proposal is for a solar wind structure
analysis via comprehensive cross-correlation analyses of solar wind field and
plasma data from the ACE, Wind and IMP 8 spacecraft. Analyses will be
performed over multi-year durations, and will assess correlation levels as
functions of spacecraft separation vectors, solar wind flow types (low vs.
high variances, low vs. high speed, CME's vs. "normal" flows, etc.) and time
resolution of data. In anticipation of this analysis, the first year will be
committed to creation of a hierarchy of data sets to be used in the analysis
and to be made community-accessible initially via the NSSDC FTPBrowser family
of interfaces. All but the last member of the hierarchy will be
spacecraft-specific. The hierarchy will consist of (1) merged
IMF-plasma-position data sets at plasma moments resolution; (2) a version of
the first set resampled at a common 1-min resolution; (3) a version of the
second set time-shifted via the minimum variance techniques of Weimer et al
(2003) to the nose of the Earth's bow shock; (4) a single 1-min data set
created by interspersing data from the spacecraft-specific time-shifted data
sets. This last data set may be considered as a high-resolution OMNI data set,
and should be very useful for solar wind-magnetosphere coupling studies. The
availability of this hierarchy of data sets will facilitate pursuit by many
researchers of studies of LWS-relevant solar wind structures and of solar
wind-magnetosphere coupling. Researchers will have the option of starting at
whatever level of the hierarchy they deem optimal for their analyses. Results
of the second-year solar wind structure analyses will contribute to the
growing understanding of such structures important for space weather
predictability purposes.
John Laming / US Naval Research Laboratory
Electron Heating in
the Solar Wind
The aim of this proposal is to model in as accurate
a fashion as possible the evolution of elemental charge state fractions in the
fast solar wind as it flow out of a coronal hole. Besides using the most up to
date atomic physics data for this work, the important new feature will be a
physics based model for the electron heating at heliocentric distance 1.5
R_sun or greater. The main goal will be to use the observed ionization
fractions to constrain as tightly as possible the electron heating, which
arises as gyrating ions in the presence of a density gradient excite lower
hybrid waves, which then damp by heating the electrons. We expect this work to
be of supreme relevance to current the NASA mission SOHO (especially the UVCS
instrument), and also to future missions such as STEREO and Solar-B.
K. D. Leka / NorthWest Research Associates, Inc.
Resolving the
180 degree Azimuthal Ambiguity in Solar Vector Magnetic Field
Measurements
Measurements of the vector magnetic field at the
photosphere are crucial to determining the magnetic field topology connecting
the photosphere to the corona, and to advancing the understanding of the
origins of solar energetic events which propagate through the heliosphere.
Inherent in those measurements, however, is a 180 degree ambiguity in the
direction of the transverse field in the image plane, which can render the
inferred measure of the vector field incorrect if not properly resolved.
Numerous algorithms exist for resolving this ambiguity in photospheric vector
field data, but all fall prey to: "the answer is straightforward when the
active region is simple, but problematic when it's interesting." Shortcomings
in the algorithms primarily stem from a lack of information on the variation
of the field with height, and rely instead upon a priori assumptions
concerning the magnetic field morphology to resolve the ambiguity. Such
approaches typically search for the azimuthal solution which minimizes a
measure of the complexity of the resulting field over the observed area. While
minimizing these quantities results in a "lowest complexity" solution, it is
not clear that the Sun itself is in the minimum state. We propose to improve
upon this situation in two ways. The capability of the U. Hawai`i/Mees Solar
Observatory Imaging Vector Magnetograph (IVM) to obtain polarimetric data in
the NaI D-2 spectral line will be exploited. The resulting magnetic field
maps, obtained at a range of heights in the solar atmosphere from the
photosphere through low chromosphere, will be used to impose div(B)=0 and
obtain the correct solution to the azimuthal ambiguity. However, this approach
is of limited utility by itself, since most vector magnetic field measurements
are available at only a single height. Thus, the multi-height observations
will be used in conjunction with model data derived from numerical solutions
to Maxwell's equations, to test algorithms which require only single-height
photospheric data. Using both multiple-height observations and simulated data,
it will be possible to determine whether the Sun is indeed in a minimum state
of magnetic complexity, and a quantity which measures that complexity. Then,
an efficient and robust algorithm for optimizing that quantity can be
determined. Although the algorithm will be developed using IVM vector field
data, the code will be made available for use with other vector field data
including that from upcoming NASA programs (e.g., Solar-B, SDO).
Janet Luhmann / University of California Berkeley
Inner
Heliosphere Multispacecraft Data Analysis Tool
We propose to
develop a web-based tool specifically for putting inner heliosphere
multispacecraft data sets in the global context provided by solar wind models
based on solar magnetic field measurements. The tool will be developed and
tested using the twin spacecraft Helios data set in conjunction with
contemporaneous near-Earth data from IMP-8 and ISEE-3. Three-dimensional
global solar wind models will be constructed from the historical solar
magnetogram data bases to provide displays and data manipulation options
exploiting measurements at different spacecraft locations. The tool will
provide new insight into the Helios mission multipoint observations using
state of the art visualization capabilities and knowledge of coronal sources
of the ambient solar wind, together with a new resource for interpreting
future STEREO and MESSENGER mission data in combination with ACE measurements.
It will similarly be ready for future LWS sentinels and any other
serendipitous or planned heliospheric constellations that similarly seek
global inner heliosphere context information for nowcasting, forecasting, or
CME event backgrounds. The project will make heavy use of students in the
user-interface design and testing of the tool.
Peter MacNeice / Drexel University
Modeling the Geoeffectiveness
of Coronal Mass Ejections
We propose to develop a community tool
that would enable users to quickly estimate the likely geo-effectiveness of
Coronal Mass Ejections, initiated using an initiation process of their
choosing . At present we have a 2.5D MHD model which has enabled us to study
the `breakout' initiation process in the inner corona. While this model is
ideally suited to study the initiation of the ejection, it is missing some
critical components which are needed to enable it to follow the eruption to 1
AU.We propose to extend the model to achieve this. These components include,
modifications to the energy balance description, and user interfaces to
control set up of both the background magnetic field and the complex field
topology required in the initiation region, and the solar wind state into
which the eruption occurs. We will add a graphical user interface to allow
users to modify the solar wind and initial magnetic field configurations, and
the final tool will be made available to the community through the CCMC and
through our web site. We will apply it to the `breakout' model, comparing
results with those from our completed studies which used a simplistic
description of the outer corona, to study the impact that a more realistic
solar wind environment has on the evolution of the CME. Our modeling tool will
report those properties of CMEs known to be key in determining
geo-effectiveness. We will encourage and facilitate proponents of other
initiatiation mechanisms in the use of the tool to perform similar studies for
those models.
Petrus Martens / Montana State University-Bozeman
Stars as Suns:
Unraveling Long-term Solar Variability by Stellar Dynamo
Modeling
We propose dynamo simulations of stars that are very
similar, but not identical to the Sun. The main goal is to better understand
the nature and evolution of the solar dynamo by studying how its main
characteristics (period, activity level), as simulated with the well tested
mean field dynamo code, vary within the parameter space close to the observed
or assumed input parameters and profiles that reproduce the solar dynamo, and
by comparing these results with the periods, X-ray and Ca HK activity levels,
that are known for various Sun-like stars. In particular we will carry out
simulations for both the Babcock-Leighton (surface) and the mean field
(convection zone) alpha-effect to determine which one reproduces better the
dynamo periods and activity levels of Sun-like stars, and thereby is the more
likely mechanism operating in stellar (and solar) dynamos. The relevance of
this work is that a better understanding of the evolution of the dynamo
mechanism will enable us to make more confident predictions for the Sun's
variability spanning from solar cycle-like timescales to stellar evolutionary
timescales. This will provide more reliable input for space weather and
Earth's climate forecasters and is relevant for understanding the long term
evolution of the Sun's magnetic field and its subsequent effect on the
Sun-Earth connection. The proposal includes partial support for a postdoc and
an undergraduate, and full support for a graduate student. It is our intention
that this project will constitute the thesis research for the graduate
student.
John McCormack / US Naval Research Laboratory
Investigating the
Influence of the 11-Year Solar Cycle on Dynamics Using a High Vertical
Resolution Zonally Averaged Photochemical-Dynamical Model of the Middle
Atmosphere
This is a proposal to examine the influence of the
11-year cycle in solar ultraviolet irradiance on the dynamics of the middle
atmosphere over the altitude region extending from the lower stratosphere to
the mesopause. Recent results from a low-vertical resolution (~2.5km) version
of the NRL CHEM2D model indicate the 11-year solar cycle can influence the
quasi- biennial oscillation in stratospheric winds, but the effect is smaller
than observations indicate. In addition, there are considerable uncertainties
in the observed solar cycle effect on temperature near the mesopause. In both
cases, current state-of-the-art interactive photochemical models may not have
sufficient vertical resolution to adequately capture interactions between
photochemical and dynamical processes that may help to explain the observed
variations. The objective of this proposal is to perform detailed model
simulations of the 11-year solar cycle with increased (0.5 km) vertical
resolution to better represent the momentum deposition by breaking gravity
waves that governs the dynamical variability of the middle atmosphere over
seasonal and interannual time scales.
Jan Merka / NRC, NASA/GSFC
Solar Wind Input into the
Magnetosphere: Assimilation of Multi-Spacecraft Data
The primary
objective of this proposal is the reconstruction of the solar wind and IMF
shear and gradients perpendicular to the Sun-Earth line by assimilating data
from multiple solar wind monitors. This will allow the consideration of
asymmetrical or non-uniform solar wind input into the magnetosphere based on
multi-spacecraft data that is magnetohydrodynamically self-consistent. NOAA
has been using L1 solar wind observations from ACE, and previously from WIND
and ISEE-3, with considerable success to forecast geo-effective events with an
approximately 45-minute warning time. However, there is still a significant
rate of false alarms and some potentially dangerous events are missed all
together. This proposal aims to enable better understanding of the solar wind
input into the magnetosphere as a result of modern data assimilation
techniques to reconstruct the variable solar wind profile across the
magnetospheric cross-section in a more realistic manner using already
available data from ACE, WIND, IMP 8, Geotail and Interball-1. The first
portion of this study will implement data assimilation techniques (statistical
interpolation) widely used in the meteorological community on the various data
sets and the 3-D MHD numerical model ENLIL of the solar wind. The
reconstructed transverse profile of the solar wind will be compared with
observations near/inside the Earth's magnetosphere in order to estimate the
gains in prediction accuracy of magnetospheric events. As a further refinement
of the assimilation process, the shapes and orientations of the interplanetary
shocks/discontinuities will be taken into account. The detailed knowledge of
the transverse solar wind profile across the magnetospheric cross-section,
which will be provided by the technique developed in this study, will allow
the development of better understanding of the Sun-Earth interactions and will
result in more accurate space weather predictions. In summary, this work will
employ modern data assimilation techniques to reconstruct the solar wind
profile, compare the results, based upon as many as five spacecraft, with
single spacecraft observations and thus provide scientific guidance for future
L1 multi-spacecraft concepts, as well as mission concepts for monitoring space
weather conditions, one of the main goals of the NASA LWS program. This
proposal aims to develop new techniques that will increase the utility of
multiple spacecraft observing the solar wind as a single observatory.
Tom Narock / NASA/GSFC/L3 Comm
Extending the LWS Data
Environment: Distributed Data Processing and Analysis
Current
studies demand the combination of data from multiple instruments aboard
different spacecraft. The curvature of shock fronts and the correlation scales
of turbulent processes serve as prime examples. The need for quick and
reliable access to this data is an ever-increasing one. In the current space
science paradigm various data sets are available from different data
providers, often in different countries. The currently developed SEC virtual
observatories (e.g. the Virtual Solar Observatory (VSO) and Virtual
Heliospheric Observatory (VHO)) primarily address the need of the scientific
community to discover and access the most appropriate space science data sets
via a user-friendly common interface that allows queries. Thus the VxOs will
locate and deliver data from a large number of missions but, at least in their
early form, will leave post-processing of the data to the user. Mere access to
distributed data is not sufficient to create a comprehensive data environment.
Specifically, there is clear need in the scientific community for some common
post-processing of the data such as re-averaging, merging of multiple data
sets to the same time grid, coordinate transformations and basic filtering and
formatting. Therefore, we propose to develop a mechanism to provide
distributed data services that can serve as an additional building block of
the VxOs. Moreover, a prototype would be deployed - providing processing
support for WIND and IMP 8 magnetometer data - to test the architecture and
would be useful to the community even before integration into the VxOs. Since
our concept is fully extensible, once the architecture is developed, tested,
and integrated into the VHO with full public documentation, other members of
the heliospheric community could add further data processing services with
relative ease.
Merav Opher / JPL-Caltech
Numerical Modeling of the Evolution of
CME Shocks in a Realistic Lower Corona and their Radio and Energetic Particles
Signatures
This proposal will address two important questions for
Living with a Star motivated by recent CME-related solar energetic particle
(SEP) and radio observations: (1) Can strong CME-driven shocks form in the
lower corona (~3 solar radii) and accelerate particles to the GeV/nucleon
energies observed in some ground level CME-related events? and (2) Can some
CMEs drive multiple coronal shocks, as suggested by radio observations,
because of the strong variations in the magnetosonic speed in the lower
corona? While it is general accepted that the largest energetic particle
events are created by CME-driven shocks in interplanetary space, the relative
importance of CME-driven shocks versus flare-related processes in creating
energetic particles low in the corona is not understood and is an area of
active research. To answer these questions, we will use the state-of-the-art
3D MHD BATS-R-US code to model CME-driven shocks in the lower corona. This
code is the most suitable for this task because its adaptive grid capability
will allow sufficient resolution near the Sun to follow the CME and shock
evolution. The CME will be modeled as a buoyant flux rope lying under a closed
field region. The MHD code will first be used to create realistic background
corona using observed photospheric fields for boundary conditions so that
results from the model can be compared to SEP and radio observations from
specific CME events. We will validate the background corona by computing the
magnetic field topology and solar wind from the Sun to 1 AU and comparing
results from the model with in situ solar wind observations from ACE. This
will be the first 3D MHD study focused on understanding the formation and
evolution of CME-driven shocks in the lower corona and their role in SEP
creation. In keeping with the goals of the LWS TR&T program, this research
will increase our scientific understanding of the basic physical processes
underlying the Sun-Earth connection. The team assembled, consisting of
scientists from JPL, the University of Michigan, GSFC and the University of
Florence, has the necessary numerical, analytic and observational experience
needed for the proposed work.
J. Michael Picone / US Naval Research Laboratory
Predicting EUV
Irradiance and Induced Upper Atmospheric Density Changes from EIT Solar
Imagery
Since solar EUV radiation controls the temperature and
composition of the upper atmosphere and ionosphere, the ability to predict the
EUV irradiance is crucial for predicting the impact of space weather, as
evidenced by upper atmosphere mass density effects on spacecraft drag, and
ionospheric electron density effects on communications and navigation. The
overall goal of the proposed work is the capability to forecast solar EUV
irradiance and induced upper atmospheric density changes on time scales of
days to weeks. The approach is to analyze the east limb portion of full-disk
EIT images to extract information about active region EUV sources on the verge
of becoming visible at the Earth. This approach is possible because sources of
bright EUV emission are loop structures that extend up to a few solar radii
above the visible surface of the disk. Bright EUV sources near the limb, but
on the far side of the Sun, can thus be present in the field of view of the
EIT EUV images. Since a bright active region has its maximum impact on EUV
irradiance roughly 7 days after it appears on the limb, when it reaches the
central meridian, we will be able to predict EUV irradiances on times scales
of days to weeks from analysis of the EIT images. We will test the predicted
EUV irradiances, determined from the EIT images, by direct comparison with the
actual irradiances to quantify the probability that the predicted irradiances
will fall within specified ranges. We will also compare the EIT-based
predictive tool with the forward propagation of the primary power identified
through statistical analysis of the irradiance time series. We will then use
the newly developed predictive tool to forecast solar EUV-induced upper
atmospheric density changes, and evaluate the space weather utility of the
work. This will be accomplished by inputting the predicted irradiances to the
NRLMSIS upper atmosphere density specification model (converted to the solar
activity proxy that the model uses). The predicted total mass densities will
be compared with actual mass density variations which we have derived in past
work from the orbits of three Starshine spacecraft during the period from 1999
to 2003, with geomagnetic effects removed. Thus we will quantify the
uncertainties of the EUV irradiance predictions in terms of induced density
changes, and hence, orbital drag.
Edward Rhodes / University of Southern California
Improvement in
the Data Environment for Global and Local Helioseismic Studies of the Changing
Solar Interior
This is a proposal to improve the data environment
for studies of the changing solar interior which are currently being carried
out within the Living With a Star Program under NASA Grant NAG5-13510.
Recently, several hints of possible temporal changes that have occurred during
Solar Cycle 23 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 so-called Solar Subsurface Weather (SSW), and the
confirmation of the existence of the so-called 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. NASA LWS Grant NAG5-13510
provides partial support for verifying that these same features can be seen in
co-temporaneous ground-based observations taken at the Mt. Wilson Observatory
60-Foot Solar Tower since the SOHO mission began in 1996 and for searching for
changes in both the meridional flow and in the torsional oscillations during
Solar Cycle 22 using earlier MWO observations obtained on an annual basis
since 1987. With the partial support of this grant, we have recently
transferred 176 consecutive days (out of a 17-year total of 3270 days) of MWO
Dopplergrams taken during mid-1996 to Stanford where we have employed two
consecutive 72-day subsets of these images to confirm the existence of the
torsional oscillations below the photosphere at that time. This data
environment proposal will leverage the support provided by the above LWS grant
since its approval will allow us to double the level of support of the three
data analysts who have been processing the past MWO data and transferring the
processed data to Stanford for analysis and permanent archival. Doubling their
support will enable us to conduct our studies using a much larger amount of
the past MWO archive than the current grant support will allow. 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. As soon as our MWO data have been archived at Stanford,
they will also be available for use by the entire helioseismic community.
Aaron Ridley / University of Michigan
A New Data Environment for
Ionospheric Electrodynamics Based on AMIE Results
In this proposal
we seek funds to make a large database of ionospheric electrodynamic
quantities available over the web. This database will be for the Northern and
Southern polar regions (extending from the poles down to +/- 46 degrees
magnetic latitude), and will include 1 minute assimilative mapping of
ionospheric electrodynamics (AMIE) results for all of 1997-2001, or 5.25
million patterns. The patterns will be of ionosphere electric potential, Hall
and Pedersen conductance, average and total electron energy flux, horizontal
and field-aligned currents, electric fields, and Joule heating. In addition,
AMIE provides the Auroral Electrojet (AE, AU, and AL) index and Dst index,
which will also be provided. If funded, we will make a user friendly front end
interface to the AMIE database.
David Rind / Goddard Institute for Space Studies
The Sun's Role
in Decadal Climate Change since 1980, and in the last Century
The
goal of this research is the empirical and modeling quantification of spatial
climate patterns associated with decadal solar forcing, as distinct from ENSO,
volcanic and greenhouse gas influences. A multiple regression of surface and
satellite-based temperature data with the observed forcings will be done for
the last 20 years, the time period covered by space-based data. The spatial
pattern of the trend component may offer clues about its origin, specifically
the relative importance of anthropogenic and solar forcings. The
forcings/events will also be input to a high resolution climate/middle
atmosphere model with chemistry to assess its responses for comparison with
the observational record. The model will allow for a detailed evaluation of
the potential response mechanisms. The analysis will then be extended to the
past 100 years, and the patterns compared to the more recent data, to
understand the consistency in response and the validity of the proposed
forcings over this time (in particular the solar forcing). The research should
provide new characterizations of contemporary regional climate responses to
solar irradiance variations.
D Aaron Roberts / Goddard Space Flight Center
Tools for Global
Understanding of the Sun-Earth System
We will develop and provide
the LWS community with a suite of related tools that will greatly aid the
understanding of large quantities of data from disparate sources, which will
be essential for attaining a global understanding of the Sun-Earth system.
SPDataShop will allow a scientist to read data in many formats (e.g., HDF,
CDF, NetCDF, FITS, ASCII) and produce a panel plot or image as well as file
output in the desired format. SPGifWalk will unite a large number of
browse-level sites offering everything from SOHO movies of the solar corona to
gif images of overview time series plots from the Polar spacecraft. SPBrowse
will use uniformly formatted survey data from many missions (including various
indices) to allow a user to examine long and short data intervals, comparing
the results from many spacecraft with ease. The survey data will also allow
simple but effective types of data mining. Finally, additions to the existing
ViSBARD 3-D visualization software will allow a scientist to see
multispacecraft data in a variety of input formats in the context of
Tsyganenko field lines and other models. All the above tools, along with
software and documentation libraries, will be integrated with the Virtual
Space Physics Observatory that is being designed under separate funding; this
will combine easy data access with many analysis tools, making, for example,
the basic analysis of a "Coordinated Data Analysis Workshop" a matter of a
day's work by a single researcher using numerical data rather than a multi-day
meeting of many people who share gif plots.
Robert Schunk / Utah State University
USU GAIM Data Assimilation
Model: A Scientific Tool for the LWS Program
The Global
Assimilation of Ionospheric Measurements (GAIM) model is a physics-based data
assimilation model of the ionized medium surrounding the Earth. It provides
specifications and forecasts on a spatial grid that can be global, regional,
or local. GAIM uses a physics-based ionosphere-plasmasphere-polar wind model
and a Kalman filter as a basis for assimilating a diverse set of real-time (or
archived) measurements, and it is capable of assimilating in situ and remote
sensing satellite data as well as ground-based data. The resulting
specifications and forecasts are in the form of 3-dimensional electron density
distributions from 90 km to 30,000 km. In addition, GAIM provides global
distributions for the self-consistent ionospheric drivers (neutral winds,
electric fields, and particle precipitation patterns), and in its
specification mode, it provides quantitative estimates for the accuracy of the
reconstructed plasma densities. We propose to install the GAIM model on the
CCMC computers so that the GAIM results will be available to the LWS community
for scientific studies. We also propose to assimilate additional data sources
and initiate a validation program.
Neil Sheeley / Naval Research Laboratory
Observational Signatures
of Time Variations in the Sun's Open Magnetic Flux
OBJECTIVES:
Geomagnetic activity is closely correlated with the strength of the
interplanetary magnetic field (IMF), which in turn varies in proportion to the
Sun's total open flux. Active region emergence, photospheric transport
processes, and coronal mass ejections (CMEs) can cause the total open flux to
increase or decrease. In situ measurements indicate that the IMF strength can
vary by a factor of 2 on timescales of months, consistent with source surface
extrapolations of the photospheric field. However, direct observational
evidence for the opening up and closing down of magnetic flux in the corona or
at 1 AU has been hard to find and/or interpret, leading to suggestions that
the open flux remains constant, simply undergoing footpoint exchanges with
closed loops. Our objectives are (1) to identify, using photospheric, coronal,
and interplanetary data, the observational signatures of the opening-up and
closing-down of flux and of footpoint exchanges; and (2) to determine whether
the locations, times, and occurrence rates of such events are consistent with
the predictions of the photospheric flux transport and potential-field
source-surface models. APPROACH: To search for signatures of the opening-up
and closing-down of magnetic flux and of footpoint exchanges, we will make use
of the large variety of data accumulated during solar cycle 23, including
coronagraph, EUV, and photospheric field observations from SOHO, near-Earth
magnetometer, plasma, and composition data from ACE and WIND, and ground-based
magnetograms and He I 10830 spectroheliograms. We will determine if
relationships exist between different types of events that might be associated
with changes in the open flux, including (1) increases or decreases in the
radial IMF strength, (2) photospheric flux emergence, (3) changes in coronal
hole boundaries, (4) gradual outward expansions of helmet streamers, (5) CMEs,
(6) streamer blobs, (7) coronal inflows, (8) electron heat flux dropouts and
other plasma sheet variations at 1 AU. In addition, we will employ flux
transport simulations and source surface extrapolations to predict changes in
open field regions, and test these predictions against the observations.
RELEVANCE: By identifying and elucidating the mechanisms that regulate the IMF
strength at Earth, the proposed cross-disciplinary research addresses
Objective 1 of the LWS TR&T program and at least one of the Specific
Research Topics of High Current Interest ("The magnetic field topology
connecting the photosphere to the corona"); also OSS Strategic Goal I, SEC
Theme, RFA 1(a), Goal II, SEC Theme, RFA 1(a), 2(a).
Paul Straus / Aerospace Corporation
Contribution of Ionospheric
Occultation Experiment (IOX) Observations to the LWS Data
Environment
The Ionospheric Occultation Experiment (IOX) is a GPS
occultation sensor that is currently in orbit on a US Air Force Space Test
Program (STP) satellite. IOX is the only currently operational GPS occultation
sensor with an ionospheric mission focus and has been collecting a substantial
database of GPS occultation data since late-2001. The IOX measurements of the
GPS L1 and L2 signals can be used to derived precise line-of-sight total
electron content (TEC) values, electron density profiles with good vertical
resolution, and L-band scintillation. These types of measurements are key to
fulfilling many LWS objectives. The IOX data is particularly useful for
scintillation (including mid-latitude) studies and assimilative model
evaluation and development. We propose to provide the science community with
on-line access to IOX data together with a simple search/browse capability and
ancillary information about IOX mission parameters useful for research.
James Thieman / Goddard Space Flight Center
A Space Physics
Archive Search and Extract (SPASE) System for Data Access and
Retrieval
This proposal concerns the Space Physics Archive Search
and Extract (SPASE) system. The existing SPASE concortium intends to create a
data search and retrieval system for the Space Physics science community. This
will allow searching for data across multiple, diverse, international data
archives through a single search mechanism. Underlying this effort is a common
data dictionary/data model that serves as an "interlingua" to translate the
user's query into the language understood by each individual archive and to
put the metadata search results into a common language for intercomparison.
SPASE allows the user to compare search results from the multiple archives
through information sorting, visualizations, etc., and to extract data sets or
parts of data sets based on these intercomparisons, such as parts of data sets
spanning common time intervals. Some initial work has been done for SPASE but
funding now is necessary to build a robust system on a reasonable timescale.
In particular, it is necessary for a critical number of collaborating archives
to be ready more or less simultaneously. Parts of SPASE require implementation
at these individual data archives. We have assembled a team that is sufficient
to demonstrate that SPASE can connect very heterogeneous archives of both
satellite and ground-based data. The SPASE system that is created will be a
very useful tool for space physics researchers even with only the archives
participating in this proposal. It will be useful not only in locating and
acquiring data, but also in connecting to services to help understand which
data are useful. While connecting the diverse data centers together we will
develop a variety of software tools which will ease the connection of other
data centers to SPASE. We anticipate others joining in the effort using their
own resources. In particular we will be working to connect with the Space
Physics Virtual Observatories as they develop. This will facilitate the
multi-discipline studies crucial to the understanding of Sun-Earth Connection
science.
Richard Thorne / UCLA
Physical Processes Responsible for
Relativistic Electron Variability in the Outer Radiation Zone over the Solar
Cycle
Our basic understanding of the physical processes responsible
for the variability of relativistic electrons in response to solar activity is
currently incomplete. These extremely energetic electrons have important
effects on life and society ranging from the disruption of satellites to the
modification of the chemistry of the middle atmosphere and associated effects
on climate and the quality of life. As an integral contribution to the LWS
program we propose to investigate the basic non-adiabatic processes
responsible for the injection, transport and loss of relativistic electrons in
the outer radiation zone. Most of the important process that violate the
adiabatic invariants involve interactions with various plasma waves. We
propose to utilize existing satellite data to characterise the properties of
relevant waves and their variability with solar activity, and then use this
data base to evaluate diffusion coefficients to describe the non-adiabatic
dynamics of relativistic electrons over the solar cycle. This will allow us to
quantify the rates of electron acceleration and loss under different
geomagnetic conditions, and thus understand why some disturbances lead to
electron enhancement while others lead to net loss. This research is is
central to NASA's interests in understanding the dynamic response of the
near-space environment to solar activity and the coupling between the
magnetosphere and the middle atmosphere.
Jon Vandegriff / Johns Hopkins University Applied Physics
Laboratory
Data Environment - Restoration of AMPTE/CHEM Data
The
Charge-Energy-Mass spectrometer (CHEM) on NASA's Active Magnetospheric
Particle Tracer Explorers Charge Composition Explorer (AMPTE/CCE) mission made
detailed measurements at high time resolution of energetic particle
populations in the inner magnetosphere. This data contains a wealth of
information about the behavior of the magnetosphere and the ring current. In
particular, the high time resolution data is useful for studying sub-storm ion
injection, as well as details about the relationship between Solar wind
changes and magnetospheric response. Yet the high time resolution data for
CHEM has never been readily available to the community. We will transition
high time resolution CHEM data from its aging VAX/VMS-based storage and put
online two new ASCII versions of the entire four and a half year dataset, one
version calibrated, one version raw counts. The data will be placed on servers
at JHU/APL and will also be archived with documentation in the NSSDC at
Goddard. Furthermore, we will make the data available in an existing web-based
tool for analyzing energetic particle data (the Mission Independent Data Layer
or MIDL; see the web site at http://sd-www.jhuapl.edu/MIDL). Finally we will
provide CHEM meta-data to emerging Virtual Observatory (VO) systems. Our
comprehensive efforts will permanently restore to the LWS program a valuable
dataset on the inner magnetosphere, a region which will soon be receiving
increased attention with the launch of the LWS Geospace Storm Probes.
Harry Warren / U.S. Naval Research Laboratory
The Magnetic
Topology of Coronal Mass Ejections
Understanding the magnetic
configurations of solar active regions that give rise to coronal mass
ejections is a major component of space weather. Coronal mass ejections can
drive geomagnetic storms, which disrupt communication and knock out power
systems. Solar energetic particles generated by the CME as it expands into the
ambient heliosphere pose a significant risk to human exploration in space as
well as to satellite systems. Mnay models of CME initiation, such as the
tether cutting and flux rope models, emphasize the activity near the core
fields. In these models shearing motions along the neutral line lead to a
build up of magnetic energy that is violently released once a critical
threshold is reached. Recent work, however, has questioned the possibility of
releasing magnetic energy from simple magnetic field topologies. The breakout
reconnection model asserts that the magnetic field associated with a coronal
mass ejection must be quadrapolar and have a null. In this model the overlying
fields constrain the fields near the neutral line and allow stress to build
up. Reconnection near the null point removes the overlying fields and permits
the stressed fields to erupt. We propose to test the breakout, tether cutting,
and flux rope models by performing a systematic study of the magnetic topology
of coronal mass ejections. We will combine SOHO MDI magnetograms with
potential and linear force-free field extrapolations and TRACE image data to
determine if complex magnetic fields are really necessary for coronal mass
ejections. We will also investigate the timing and location of pre-flare
reconnection.
Simon Wing / Johns Hopkins University, Applied Physics
Laboratory
3D Empirical Tools for the Magnetotail
The roadmap of
NASA SEC STP calls for launch of several multispacecraft missions, namely
Magnetospheric Multiscale (MMS), Magnetospheric Constellation (MC), and
Geospace Electrodynamic Connections (GEC). NASA SEC LWS program will also
launch complementary multispacecraft missions, e.g., Ionospheric Mappers (IM).
New technique will be required to assimilate and display these multi-point
measurements in the ionosphere and magnetosphere into coherent and unified 3D
global images of the magnetotail. We have previously developed a method for
inferring plasma sheet ion density (n), temperature (T), and pressure (p) from
ionospheric observations. This method relies heavily on the accuracy of the
ionosphere-magnetosphere mapping, which shall be improved with a new
technique. The new technique could be applied and tested on the existing NASA
and non-NASA satellites. The resulting 2-D/3-D plasma sheet profiles not only
help guide the upcoming multi-spacecraft missions, e.g. spacecraft orbits and
spacing, but also contribute to the NASA LWS science objectives. Therefore, we
propose to (1) radically improve the ionosphere-magnetosphere mapping using
grad p= j x B relationship; (2) expand the method to incorporate mid-altitude
and high-altitude measurements; (3) construct 2-D/3-D plasma sheet n, T, and p
from DMSP observations for over one solar cycle binned by solar wind and IMF
parameters as well as storm and substorm onset times; (4) link our model
profiles to Fok ring current-radiation belt model [Fok et al., 2001]; and (5)
develop a 3-D magnetotail viewer. Relevance to NASA LWS Program The proposed
work can significantly aid the upcoming NASA SEC STP and LWS multi-spacecraft
missions. In addition, it is relevant to the NASA LWS TR&T Objective 2,
which calls for developing new empirical tools and numerical simulations that
predict the occurrence and amplitudes of solar, interplanetary, and geospace
disturbances, including software that identifies, retrieves, assimilates, and
portrays data and model results from different sources for LWS forecasting and
research objectives
(http://research.hq.nasa.gov/code_s/nra/current/nra-03-oss-01/appendA3_7.html).
The proposed work addresses 3 NASA OSS Science Objectives and Research Focus
AREAS (RFAs): (1) Goal I, Sun-Earth Connection Theme, RFA 1(b); (2) Goal II,
Sun-Earth Connection Theme, RFA 1(c); and Goal II, Sun-Earth Connection Theme,
RFA 2(b).
Yuk Yung / California Institute of Technology
Solar Forcing of
Climate through Stratospheric Ozone Changes
There is compelling
evidence that solar variability is implicated in climate change, but no
credible mechanism has been established to date. The main difficulty in
establishing a mechanism is that changes in total solar radiation absorbed at
the surface are too small to explain observed changes in climate. We propose
to investigate a mechanism that amplifies the influence of the sun through
UV-induced ozone changes in the stratosphere. We will test our hypothesis by
investigating various historical periods that have anomalous temperature and
solar activity levels such as the Maunder Minimum and the Medieval Maximum. We
propose a four-pronged approach to study the solar forcing of climate through
stratospheric ozone changes. We will first investigate the well-documented
changes in the ozone layer and their associated climate changes for the last
two solar cycles. We will model the response of ozone in the stratosphere to
UV changes using a 2-D photochemical model that includes the effects of
realistic quasi-biennial oscillation and catalytic chemistry. The radiative
forcing due to ozone changes will be modeled using the MODTRAN code and
compared to data from NCEP/DOE Reanalysis II. The changes in stratospheric
ozone and radiative forcing will be used as input to an idealized GCM to drive
changes in heating rates and the stratospheric zonal wind patterns. These
changes will affect the strength of the stratospheric polar vortex by changing
the propagation of upwelling planetary-scale waves, which in turn can effect
tropospheric dynamics. Therefore, the ozone-induced changes in stratospheric
winds can indirectly affect tropospheric climate. The experience gained from
the idealized GCM will be used to carry out more realistic investigations
using the Whole Atmosphere Community Climate Model of NCAR. We will analyze
the state of the paleoclimate climate using the most recently obtained data
and compare the model-predicted impacts with these data. We have shown that
the tropospheric Northern Annular Mode is influenced by changes in the solar
UV radiation, suggesting that a mechanism of solar influence on climate
involves modulation of this mode. Our proposed mechanism couples the changes
in solar UV emission to those of ozone and ultimately tropospheric dynamics.
If we successfully demonstrate that this mechanism is at work in the best
climate models, this study will open a door to future space-borne observations
of the solar-climate relationship.
Eftyhia Zesta / University of California, Los Angeles
Space
Weather Effects of Solar Wind Pressure Fronts: Atmospheric Energy Input and
MeV Particle Energization
Recent studies have suggested that solar
wind dynamic pressure enhancements can cause energetically very significant
disturbances in our environment's Space Weather. Specifically, large amounts
of energy are deposited on the Earth's upper atmosphere and energetic
particles in the inner magnetospheric region are further energized. We propose
to use dynamic pressure step changes and long-lasting pressure pulses in the
solar wind unambiguously identified from 2-point measurements from SoHO and
WIND from 1996 to present to determine the specific affect of such pressure
fronts on the total energy input to the Earth's upper atmosphere and the
energization of MeV particles in the inner magnetosphere. Complementary solar
wind data from IMP 8, ACE, Geotail, and Interball 1 spacecraft will also be
used when available in order to more accurately determine the timing of the
pressure front impact on the magnetosphere. We will then use data from ground
magnetometers (MACCS, CANOPUS, Greenland), the SuperDARN radars, all-sky
imagers and median scanning photometers, Polar UVI, IMAGE FUV, low-altitude
DMSP, and geosynchronous LANL and GOES spacecraft to determine the
magnetospheric and ionospheric response and the temporal propagation of this
response across the magnetosphere and ionosphere. We will focus our research
on answering the following three scientific questions regarding the responses
to solar wind pressure fronts: 1) the response of the auroral precipitating
flux to solar wind pressure enhancements for different IMF conditions, 2) the
response of the ionospheric and large-scale field-aligned currents as well as
the ionospheric Joule heating under different IMF conditions, and 3)
energization of MeV particles in the inner magnetosphere under different IMF
conditions before and during the pressure front event. We will then
investigate the physics driving the responses using the UCLA-GGCM global MHD
model. This will be accomplished by comparing the observations with the
results of the model, identifying what major features of the observations can
be accounted for by the model and determining the causes of those features
using properties in the model. We will also determine what features of the
observations cannot be explained by the model physics, thus providing the
modelers with clues on how to improve the model.
Jie Zhang / Center for Earth Observing and Space Research/George
Mason U
A Systematic Study on Solar Sources of Major Geomagnetic Storms
from 1996 to 2006
We propose to systematically investigate solar
sources of major geomagnetic storms for an entire solar cycle from 1996 to
2006. This is based on our previous limited study for a period from 1996 to
2000. There are three major tasks: (1) unambiguously identify solar CMEs that
are responsible for major geomagnetic storms and their surface source regions,
(2) study the properties of geo-effective solar CMEs and their interplanetary
counterparts (Interplanetary CMEs), and structural and magnetic linkage
between solar CMEs and ICMEs (3) build an empirical model to predict onset
time and intensity of major geomagnetic storms using solar inputs. The
observational data used in this project include (1) ground-based observations
of geomagnetic activity index Dst (2) in-situ solar wind plasma and magnetic
observations in near-Earth space from ACE and WIND experiments, (3) solar CME
observations from the LASCO instrument on SOHO, (4) coronal observations from
the EIT instrument on SOHO, (5) solar magnetic observations from the MDI on
SOHO, (6) other routine solar observations, e.g., flares and filaments. The
data product of this project is a comprehensive set of geo-effective Sun-Earth
connection events containing information on their source regions, and
properties of the corresponding solar CMEs and ICMEs. The scientific goals are
to answer what and why certain CMEs are particularly geo-effective, and what
are the physical (structural and magnetic) connection between solar CMEs and
ICMEs. The potential application of this project is to build an
empirical-based model to predict major geomagnetic storms 30-100 hr in
advance.