Global Distribution Of Nmf2 And Hmf2 Seen By Cosmic-2 Satellites

Abstract

This study investigates the diurnal and seasonal variations of the low latitude ionosphere using COSMIC-2 radio occultation data in 2020-2021. By analyzing electron density profles, intriguing patterns are revealed in the distributions of NmF2 and hmF2. During the daytime, NmF2 displays two equatorial ionization anomaly (EIA) peaks gradually separating from the magnetic equator, while hmF2 peaks remain confned to the magnetic equator. NmF2 exhibits a daytime increase and subsequent decrease, while hmF2 shows an abnormal rise around 20 LT. The seasonal analysis highlights the December solstice as having the highest intensity of NmF2, indicating a dominant annual asymmetry in the low-latitude ionosphere. Additionally, hemispheric asymmetry in hmF2 is observed during solstices, attributed to wind convergence patterns. These fndings contribute to our understanding of ionospheric behavior in the low latitude region and advance the felds of space science.