Solar zenith angle dependence of relationships between energy inputs to the ionosphere and ion outflow fluxes

作     者：Kitamura, Naritoshi Seki, Kanako Keika, Kunihiro Nishimura, Yukitoshi Hori, Tomoaki Hirahara, Masafumi Lund, Eric J. Kistler, Lynn M. Strangeway, Robert J. 

作者机构：Department of Earth and Planetary Science Graduate School of Science The University of Tokyo Japan Department of Electrical and Computer Engineering Center for Space Physics Boston University BostonMA United States Institute for Space-Earth Environmental Research Nagoya University Furo-cho Chikusa-ku Nagoya Japan Institute for the Study of Earth Oceans and Space University of New Hampshire College Brook Scientific DurhamNH United States Institute for the Study of Earth Oceans and Space University of New Hampshire Department of Physics University of New Hampshire DurhamNH United States Department of Earth Planetary and Space Sciences University of California in LA Los AngelesCA United States 

出 版 物：《Research Square》 (Research Square)

年 卷 期：2021年

核心收录：

主　　题：Carrier concentration 

摘      要：The ionosphere is one of the important sources for magnetospheric plasma, particularly for heavy ions with low charge states. We investigate the effect of solar illumination on the number flux of ion outflow using data obtained by the Fast Auroral SnapshoT satellite at 3000–4150 km altitude from 7 January 1998 to 5 February 1999. We derive empirical formulas between energy inputs and outflowing ion number fluxes for various solar zenith angle ranges. We found that the outflowing ion number flux under sunlit conditions increases more steeply with increasing electron density in the loss cone or with increasing precipitating electron density (50 eV), compared with the ion flux under dark conditions. Under ionospheric dark conditions, weak electron precipitation can drive ion outflow with small averaged fluxes (~107 cm−2 s−1). The slopes of relations between the DC and Alfvén Poynting fluxes and outflowing ion number fluxes show no clear dependence on solar zenith angle. Intense ion outflow events (108 cm−2 s−1) occur mostly under sunlit conditions (solar zenith angle © 2021, CC BY.