National Aeronautics and Space Administration

Living With A Star

Targeted Research and Technology

Daytime Multiwavelength Ground-Based Optical Investigations of Precursors to Low-Latitude Plasma Irregularities

ROSES ID: NNH05ZDA001N      Selection Year: 2006      

Program Element: Independent Investigation

Principal Investigator: Pallamraju Duggirala

Affiliation(s): Center for Space Physics

Project Member(s):
Baumgardner, Jeffrey L Co-I Trustees of Boston University


We propose a 3-year project to carry out systematic investigations of the precursors to the ESF irregularities during daytime using a ground-based optical multiwavelength Echelle spectrograph to be built at BU. Equatorial Spread-F (ESF) refers to the presence of plasma irregularities at low- and equatorial latitudes in the nighttime ionosphere. Unlike substorms and geomagnetic storms, ESF is a form of space weather not controlled exclusively by the Interplanetary Magnetic Field (IMF). ESF irregularities severely impact radio communications and navigational systems at a wide range of frequencies that adversely affect commercial and defense applications. The development of these irregularities is highly unpredictable. Even during the ESF season when various onset parameters are nearly identical, ESF occurs on one night and is completely absent on the other. Scientifically, this is a key-missing element in our understanding of plasma instabilities at low latitudes. This proposed work will carry out daytime optical measurements to investigate the roles of neutral parameters, such as the meridional and vertical winds and waves that are known to be effective triggers to the ESF. For the first time in history, we will have a large field-of-view multiwavelength spectrograph that is most suited to answer these relevant issues. We will carry out daytime measurements using three emissions 5577, 6300 and 7774 , which originate around 100, 230 and 300 km, respectively. These large field-of-view measurements will enable us to investigate waves and their direction of propagation at three different altitudes. The results from this study will not only resolve issues surrounding the precursors to ESF but will substantially enhance our understanding of the interaction of daytime and nighttime phenomena of the low-latitude/ equatorial electrodynamics in upper atmosphere.

We plan to operate the new instrument at Carmen Alto (23.1^o S, 70.6^o W; 10.2^o S dip lat.), in Chile. This data will be used in conjunction with the multi-diagnostics of the Multi-Instrumented Studies of Equatorial Thermosphere Aeronomy (MISETA) consortium operating in the American longitude sector as well as Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite and Communicational/Navigational Outage Forecast System (C/NOFS) mission (scheduled to be launched in 1996). Furthermore, Jicamarca Unattended Long-term Investigations Atmosphere (JULIA) radar data, Jicamarca Radio Observatory (JRO) data, Global Positioning Systems (GPS) and Defense Meteorological Satellite Program (DMSP) data will be available for independent confirmation of the occurrence of ESF irregularities and for the information on the background thermosphere/ionosphere conditions in conjunction with our ground-based data. This dayglow data at multiple wavelengths will add to the rich database and a unique resource to the community.
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