What Can We Learn from the Equatorial ionization Anomaly (EIA) Locations in GOLD Observations?

Abstract:

The Global-scale Observations of the Limb and Disk (GOLD) mission observes the spatial and temporal changes that occur in the nightside EIA over South America, the Atlantic Ocean and western Africa. Each night GOLD repeatedly scans these regions, covering ~70 degrees of longitude (~5 hours) and all latitudes. These observations include one of Earth’s most interesting low-latitude areas, where the geographic and geomagnetic equators cross, with the geographic north of the geomagnetic equator over South America (where the difference is maximum) and south of the geomagnetic equator over the Atlantic and Africa. The EIA’s global-scale, temporal behavior is difficult to study adequately using ground based or satellite observations from low-earth-orbit (LEO) due to the limited spatial-temporal coverage such observations provide. These limitations have biased our understanding of the thermosphere-ionosphere (T-I) system, an understanding that is important to current and future space weather needs. Initial GOLD results have shown that rapid (within 10s of minutes) and large scale (< 10 degrees of longitude) changes in the location as well as the brightness of the EIA are observed. Seasonal changes in the EIA location also have a longitude dependence. This presentation will describe such changes and discuss the implications.