Zonal winds in the equatorial upper thermosphere: Decomposing the solar flux, geomagnetic activity, and seasonal dependencies

Using 3 years (2002–2004), over 16,400 orbits of measurements from the accelerometer on board the CHAMP satellite, we have studied the climatology of the equatorial zonal wind in the upper thermosphere. Several main features are noticed. The most prominent one is that the solar flux significantly influences both the daytime and nighttime winds....

Thermospheric mass density variations during geomagnetic storms and a prediction model based on the merging electric field

With the help of four years (2002–2005) of CHAMP accelerometer data we have investigated the dependence of low and mid latitude thermospheric density on the merging electric field, Em, during major magnetic storms. Altogether 30 intensive storm events (Dstmin <?100 nT) are chosen for a statistical study. In order to achieve a good correlation Em...

Strong thermospheric cooling during the 2009 major stratosphere warming

Thermospheric density simultaneously observed by the CHAMP and GRACE satellites in both the pre?dawn and afternoon local time sectors undergoes significant decrease across both hemispheres during the major stratospheric sudden warming (SSW) in January 2009. This decrease is largest in the equatorial region near the subsolar latitude, reaching ...

Equatorial electrodynamics and neutral background in the Asian sector during the 2009 stratospheric sudden warming

Using ground observations of total electron content (TEC) and equatorial electrojet (EEJ) in the Asian sector, along with plasma and neutral densities obtained from the CHAMP satellite, we investigate the ionospheric electrodynamics and neutral background in this longitude sector during the major stratospheric sudden warming (SSW) in January...

Controlling of merging electric field and IMF magnitude on storm-time changes in thermospheric mass density

The controls of merging electrical field, Em, and IMF (interplanetary magnetic field) magnitude, B, on the storm-time changes in upper thermospheric mass density are statistically investigated using GRACE accelerometer observations and the OMNI data of solar wind and IMF for 35 great storms during 2002–2006. It reveals the following: (1) The...

Comparison of drift velocities of nighttime equatorial plasma depletions with ambient plasma drifts and thermospheric neutral winds

This is the first study to compare plasma depletion drifts with the ambient plasma drifts and neutral winds in the post sunset equatorial ionosphere using global-scale satellite observations. The local time and latitude variations of the drift velocities of O+ plasma depletions at 350–400?km altitude are derived from the observations of the far...

A gravity assist mapping for the circular restricted three-body problem using Gaussian processes

Inspired by the Keplerian Map and the Flyby Map, a Gravity Assist Mapping using Gaussian Process Regression for the fully spatial Circular Restricted Three-Body Problem is developed. A mapping function for quantifying the flyby effects over one orbital period is defined. The Gaussian Process Regression model is established by proper mean and...