Dynamics of the Equatorial Thermosphere Anomaly using Data from GOCE Satellite

We investigate the Equatorial Thermosphere Anomaly (ETA) (also known as the neutral anomaly) using accelerometer-derived neutral density data from dusk-side passes of the Gravity field and steady-state Ocean Circulation Explorer (GOCE) satellite. The anomaly peaks detected on geomagnetically quiet days from January 7th to 12th, 2013 show 5% - 10% increase in neutral density compared to background. The density peaks form within -20 to +20 geographic latitude and are correlated with the EIA peaks, as seen in TEC data across South American longitude sector. The seasonal distribution of the ETA peaks shows maximum occurrence frequency during the equinoxes and minimum occurrence frequency during northern summer, which is correlated with the seasonal variation of the dusk-side equatorial ionospheric vertical plasma drift. The available GOCE data from 2009-2013 shows a higher occurrence frequency of ETA peaks during solar maximum. Further studies involve investigating the impact of equatorial vertical plasma drift and meridional neutral wind as the contributing factors for the creation of dusk-side ETA structures.