Predicting storm-time thermospheric mass density variations at CHAMP and GRACE altitudes

R Liu,S.-Y Ma,H Lühr

doi:10.5194/angeo-29-443-2011

Abstract

Abstract. Orbit-averaged mass density measurements derived from the satellites CHAMP and GRACE are used to investigate the storm-time prediction model developed by Liu et al. (2010) at different altitudes. This model uses as input only the solar wind merging electric field. From 2002 to 2005 in total 31 major geomagnetic storms with minimum Dst

Highlights

The study of thermospheric mass density has been a topic of great importance since more and more spacecraft are launched into the height range of several hundred kilometers altitude
The density readings averaged over an orbit, ρavg, from CHAllenging Minisatellite Payload (CHAMP) and Gravity Recovery And Climate Experiment (GRACE) are used to study the stormtime response to the preprocessed merging electric field
We would like to repeat the important parts only briefly: the density measurements at mid and low latitudes are averaged for each CHAMP/GRACE orbit; high latitude regions are excluded because the density here responds to heating and composition change during magnetic storms (e.g. Lei et al, 2010a)

Summary

Introduction

The study of thermospheric mass density has been a topic of great importance since more and more spacecraft are launched into the height range of several hundred kilometers altitude. Understanding the behavior of thermospheric mass density is essential for the control of spacecraft flying in low-Earth orbit. During geomagnetic storms a larger amount of energy is deposited in the upper atmosphere at high latitudes in the form of Joule heating and particle precipitation. The local heating of neutral particles leads to upwelling in the source region. Energy and momentum are redistributed in the form of global meridional circulations and large-scale traveling atmospheric disturbances (TAD) (Bruinsma and Forbes, 2007). A series of complex physical processes lead to strong disturbances of the thermospheric mass density during magnetic storms A series of complex physical processes lead to strong disturbances of the thermospheric mass density during magnetic storms (e.g. Liu and Luhr, 2005)

Results

Discussion

Conclusion