GOLD Observations of Longitudinal Variations in the Nighttime Equatorial Ionization Anomaly (EIA) Crests' Latitudes

Abstract

AbstractEach day the Global‐scale Observations of the Limb and Disk imager observes the equatorial ionization anomaly (EIA) near sunset from ∼10°E to ∼80°W geographic longitude. Most images cover ∼45° of longitude (∼3 hr), and most longitudes are observed multiple times. Monthly averages of EIA crests' latitude (EIA lats) versus longitude during March, September, and December 2020 have been analyzed. The EIA lats reflect the combined influence of winds, solar radiation, and fields (electric and magnetic) in the equatorial region. Winter solstice differs significantly from the equinoxes, which are similar, but there are notable similarities between all three. The similarities in the EIA lats during the seasons examined indicates that the magnetic equator to subsolar point separation influences them in all three seasons and that it has a more distinct, possibly more significant, influence than winds on the average latitudes.