Anomalous Behavior of the Equatorial Ionization Anomaly During the 2 July 2019 Solar Eclipse

Abstract

AbstractA solar eclipse is a spectacular phenomenon resulting from a Sun‐Moon alignment as viewed from the Earth. Eclipses have a great influence on the state of the ionosphere and trigger significant variations during this extraordinary event, as daytime sunlight turns to darkness and back again. Therefore, understanding how this dramatic solar‐lunar event affects the Earth's atmosphere is of enormous importance. In this study, we took advantage of the proximity of a 2 July 2019 solar eclipse to the equatorial ionization anomaly (EIA) in order to investigate EIA dynamics during the eclipse total obscuration as it made its first landfall over the South American continent. We found the following eclipse dynamic features (1) analogous to prior results at the EIA, a 57% enhancement of the total electron content (TEC) in the EIA crest during total obscuration in areas a few degrees to the north from totality; (2) a 35% TEC suppression along the path of totality to the south of the EIA (sub‐EIA) crest; (3) temporal and spatial extension of the southern EIA crest; (4) enhancement of the fountain effect and associated with it vertical plasma drift in the magnetic equatorial region; and (5) unusual observation of TEC bite‐out near the EIA crest prior to local eclipse onset.