HR: 0800h
AN: SA51A-1111    [Abstracts]
TI: Inferring storm induced variations in thermospheric composition over low-latitudes using ground-based daytime optical airglow emissions
AU: * Pallamraju, D
EM: dpraju@bu.edu
AF: Center for Space Physics, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 United States
AU: Chakrabarti, S
EM: supc@bu.edu
AF: Center for Space Physics, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 United States
AU: Solomon, S C
EM: stans@ucar.edu
AF: National Center for Atmospheric Research, High Altitude Observatory 3450 Mitchell Ln, Boulder, CO 80301 United States
AB: Ground-based optical emissions from Carmen Alto, a low-latitude site, were obtained using HIRISE during November 2001. During November 6, 2001 geomagnetic storm the DST reached values of about 300 nT. HIRISE -measured daytime thermospheric (630.0nm) emissions showed large enhancement in morning hours of November 6, which were similar in magnitudes to the typical daytime peak brightness. These measurements over a wide field-of-view indicated a steady propagation of emission brightness from high- to low- latitudes. Latitudinal TEC values along the western coast of South America on that day showed an inter-hemispheric asymmetry, which indicates the presence of strong neutral winds. Further, no change in electron densities is observed on this day. Hence, the enhancement in the daytime redline emissions are believed to be due to changes in neutral temperature and composition. Comparison of the HIRISE measured emissions with GLOW model 630.0nm emissions for varying inputs of neutrals reveal a factor of 3 - 4 increase in oxygen to molecular nitrogen ratio on that day along with a few percent variations in the neutral temperatures. These results will be compared with physics based global models such as TIMEGCM on quiet and disturbed periods.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0310 Airglow and aurora
DE: 0350 Pressure, density, and temperature
DE: 0355 Thermosphere: composition and chemistry
DE: 0358 Thermosphere: energy deposition (3369)
SC: SPA-Aeronomy [SA]
MN: Fall Meeting 2005