ASTRA personnel are involved in the interpretation of GRACE accelerometer data to investigate thermospheric density variations (Why is this important?) . These density variations are not well understood, and can vary by 100% along a single satellite orbit. Although the GRACE mission is designed to improve our specification and understanding of Earth’s gravity field, the highly sensitive accelerometers on each satellite provide data that can be analyzed to obtain thermospheric density and winds. The largest densities occur at high latitudes during geomagnetic activity.
The TIME-GCM is being used to validate the GRACE density data, and to interpret the mechanisms causing the density perturbations. We are interpreting the model results to determine the drivers of the observed density enhancements.