HR: 1330h
AN: SA23A-05    [Abstracts]
TI: LWS Investigation of Middle-Latitude Topside Ionospheric Vertical Electron-Density Profiles
AU: Benson, R F
EM: robert.f.benson@nasa.gov
AF: NASA/Goddard Space Flight Center, Code 612.2, Greenbelt, MD 20771 United States
AU: Grebowsky, J M
EM: joseph.m.grebowsky@nasa.gov
AF: NASA/Goddard Space Flight Center, Code 612.2, Greenbelt, MD 20771 United States
AU: * Webb, P A
EM: pwebb@lepvax.gsfc.nasa.gov
AF: SP System, Inc/Goddard Space Flight Center, Code 612.3, Greenbelt, MD 20771 United States
AB: A Living With a Star (LWS) Targeted Research and Technology (TR&T) proposal has been selected 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 is 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, can 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 (SEDs). The approach used is to determine the locations of mid-latitude O+/H+ transition altitudes by fitting the topside Ne profiles with modeled H+ and O+ profiles that have the base electron temperature and temperature gradient at 400 km as variables. The investigation makes use of existing topside Ne profiles obtained from 1960's manual scaling of 35-mm film-format ionograms, available from ftp://nssdcftp.gsfc.nasa.gov/, and profiles deduced from digital topside ionograms available from http://nssdc.gsfc.nasa.gov/space/isis/isis-status.html.
DE: 2431 Ionosphere/magnetosphere interactions (2736)
DE: 2435 Ionospheric disturbances
DE: 2437 Ionospheric dynamics
DE: 2443 Midlatitude ionosphere
DE: 2467 Plasma temperature and density
SC: SPA-Aeronomy [SA]
MN: 2005 Joint Assembly