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
Summary:
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.