On the solar activity dependence of midnight equatorial plasma bubbles during June solstice periods  

作　　者：K.K.Ajith S.Tulasi Ram GuoZhu Li M.Yamamoto K.Hozumi C.Y.Yatini P.Supnithi 

机构地区：[1]Key Laboratory of Earth and Planetary Physics,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China [2]Indian Institute of Geomagnetism,Mumbai,India [3]Beijing National Observatory of Space Environment,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China [4]College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China [5]Research Institute for Sustainable Humanosphere,Kyoto University,Uji,Japan [6]National Institute of Information and Communications Technology,Tokyo,Japan [7]Space Science Center,Indonesian National Institute of Aeronautics and Space,Indonesia [8]School of Engineering,King Mongkut’s Institute of Technology Ladkrabang,Chalongkrung Rd,Ladkrabang,10520 Bangkok,Thailand

出　　处：《Earth and Planetary Physics》2021年第5期378-386,共9页地球与行星物理（英文版）

基　　金：partly supported by the National Natural Science Foundation of China(42020104002);by a Postdoctoral Fellowship at the Institute of Geology and Geophysics,Chinese Academy of Sciences(IGGCAS);partially supported by JSPS KAKENHI Grant Number 20H00197。

摘　　要：The occurrence of midnight Equatorial Plasma Bubbles(EPBs)during the June solstice period of the ascending phase of solar cycle 24,from 2010 to 2014,was studied using data from the 47 MHz Equatorial Atmosphere Radar(EAR)at Kototabang,Indonesia.The analysis shows that the occurrence of midnight hour EPBs was at its maximum during the low solar activity year 2010 and monotonically decreased thereafter with increasing solar activity.Details of the dependence of midnight hour EPB occurrence on solar activity were investigated using SAMI2 model simulation with a realistic input of E×B drift velocity data obtained from the CINDI-IVM onboard the C/NOFS satellite.Results obtained from term-by-term analysis of the flux tube integrated linear growth rate of RT instability indicate that the formation of a high flux tube electron content height gradient(steep vertical gradient)region at higher altitudes,due to the elevated F layer,is the key factor enhancing the growth rate of RT instability during low solar activity June solstices.Other factors are discussed in light of the relatively weak westward zonal electric field in the presence of the equatorward neutral wind and north-to-south transequatorial wind around the midnight hours of low solar activity June solstices.Also discussed are the initial seeding of RT instability by MSTIDs and how the threshold height required for EPB development varies with solar activity.

关 键 词：equatorial plasma bubbles equatorial ionosphere ionospheric instabilities and irregularities 

分 类 号：P352[天文地球—空间物理学] P353.7[天文地球—地球物理学]