Comparisons of in situ ionospheric density using ion velocity meters onboard FORMOSAT-7/COSMIC-2 and ICON missions

Earth, Planets and Space

Full Paper

Rajesh Panthalingal Krishanunni¹  Shih-Ping Chen¹  Jong-Min Choi¹  Charles Chien-Hung Lin¹  Jia-Ting Lin¹  Jaeheung Park²  Young-Sil Kwak²  Min-Ti Chang³ 

[1] Department of Earth Sciences, National Cheng Kung University, Tainan, Taiwan;Korea Astronomy and Space Science Institute, Daejeon, South Korea;University of Science and Technology, Daejeon, South Korea;Taiwan Astronomical Educational Area, Tainan, Taiwan;

关键词: FORMOSAT-7/COSMIC-2;    ICON;    IVM ion density;    Solar minimum;    Equatorial plasma bubble;   

DOI  :  10.1186/s40623-022-01759-3

 received in 2022-06-16, accepted in 2022-12-22,  发布年份 2022

来源: Springer

【 摘 要 】

We report the preliminary inter-satellite comparisons of the in situ ion density measurements by the ion velocity meter (IVM) onboard FORMOSAT-7/COSMIC-2 (F7/C2) and Ionospheric Connection Explorer (ICON) missions, during the solar minimum period of December 2019 to November 2020. The initial comparisons reveal identical diurnal, seasonal, and latitude/longitude variations in the two ion-density measurements, with F7/C2 consistently yielding stronger values than ICON, which could partly result from the difference in their orbit altitudes. The diurnal variation in the equatorial region did not show any effect of pre-reversal enhancement (PRE) during 2019–2020. The daytime plasma distributions show larger ion densities over a narrow latitudinal belt around the geomagnetic equator in all seasons, and the low-latitude densities reveal signatures of hemispherical asymmetry, with larger values occurring in the summer hemisphere. The observations also reveal distinct wavenumber-4 longitudinal modulation, which is most prominent in equinox and becomes less distinguishable during December solstice months. The simultaneous observations from F7/C2 IVM and ICON IVM also provide opportunities to study the spatial configuration and time evolution of ionospheric irregularities in the equatorial and low latitude regions. The F7/C2 and ICON simultaneously observed the equatorial plasma bubbles (EPBs) occurring around Taiwan on 18 October 2020, and the observations are consistent with each other. The EPBs were also observed by an all-sky imager located in Taiwan, comparing the satellite observations.Graphical Abstract

【 授权许可】

CC BY   
© The Author(s) 2023

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