Thermospheric Density Cells at High Latitudes as Observed by GOCE Satellite: Preliminary Results

This study provides a climatological view of density cell structures at high latitudes in the lower thermosphere, using neutral mass density at 270 km derived from Gravity field and steady-state Ocean Circulation Explorer (GOCE) satellite. Three types of the density cells named isolated low, isolated high, and wavy density cells are analyzed. Our results revealed that the density cell structures generally occur in the Northern Hemisphere and the local summer, but they are less frequently observed in the Southern Hemisphere. The low density cell tends to have greater occurrence in the dawn side than in other sampled local times, while the high and wavy density cells occur more frequently in the morning side in terms of the GOCE trajectory. Moreover, the characteristics of density cell structures, including the central locations, horizontal scales, and relative magnitudes, strongly depend on the type of the density cell structure. These results can serve as a baseline to further validate the theoretical models and also to improve our understanding of the density variability of the lower thermosphere at high latitudes.