Satellite Drag Validation of the Thermosphere-Ionosphere Electrodynamics General Circulation Model.

摘要

Orbital drag errors impact many Air Force missions including predicting re-entry times and locations, collision avoidance warnings and maintenance of the world s best catalog of all space objects. The empirical operational satellite drag models have had persisting deficiencies in their orbit predictions. The potential of physics based models for more accurate space weather predictions is currently under intense scientific investigation. Model development efforts require appropriate validation efforts. We evaluate key attributes of the Thermosphere-Ionosphere Electrodynamics General Circulation Model (TIEGCM) developed by the National Center for Atmospheric Research. This validation uses accelerometer neutral density data from the CHAMP and GRACE satellites near 400 km and 500 km altitude respectively and the historic Air Force SETA data near 200 km altitude. Key physics improvement areas needed for a next generation satellite drag modeling are elucidated by evaluating model performance relative to thermosphere variability due to solar cycle, day of year and geomagnetic activity. Data assimilation is shown to be an effective mechanism for improving model specification and forecast accuracy.