Matching CHAMP and C/NOFS Climatology at Low Latitudes with the ionosphere-thermosphere TIEGCM and the plasmasphere GIP Models

The equatorial orbiting Communications/Navigation Outage Forecasting System (C/NOFS) satellite observations from 400-800km started in mid-2008 in a period of deep solar minimum where the 10.7 cm solar radio flux flattened out around 67. By 2012, the solar flux increased to about 135. The polar orbiting CHAllenging Minisatellite Payload (CHAMP) satellite observations between about 410-310km above the equator are available from 2000 to 2010 from high to very low solar flux conditions. CHAMP Planar Langmuir Probe (PLP) observations of the electron density and temperature and the instrument measuring neutral cross-track winds (mostly zonal) are used. C/NOFS PLP, Ion Velocity Meter (IVM), and Vector Electric Field Instrument (VEFI) observations are used. The IVM package gives cross-track ExB ion drifts (meridional/upward and perpendicular) which can be mapped to the magnetic equator, along with a Retarding Potential Analyzer (RPA) for along-track ion drifts (zonal), plus [O+] composition and ion temperatures. VEFI also gives meridional/upward and zonal ion drifts. We compare climatological observations in equinox and winter with empirical models, and with the first-principles model estimates from the Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIEGCM), coupled with the Global Ionosphere-Plasmasphere (GIP) model, with various tidal forcings from the lower atmosphere. We compare longitude variations as well as local time zonal averages between the observations and model results. We also compare with ground observations of the meridional/upward and zonal ion drifts from the magnetic equator at Jicamarca, Peru.