Occurrence characteristics of branching structures in equatorial plasma bubbles:a statistical study based on all-sky imagers in China  

作　　者：Kun Wu JiYao Xu YaJun Zhu Wei Yuan 

机构地区：[1]State Key Laboratory of Space Weather,National Space Science Center,Chinese Academy of Sciences,Beijing 100190,China [2]School of Astronomy and Space Science,University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Earth and Planetary Physics》2021年第5期407-415,共9页地球与行星物理（英文版）

基　　金：supported by the Youth Science and Technology Innovation Foundation of NSSC;the International Partnership Program of Chinese Academy of Sciences(183311KYSB20200003);the National Natural Science Foundation of China(41831073 and 42004138);the Open Research Project of Large Research Infrastructures of CAS–“Study on the interaction between low/mid-latitude atmosphere and ionosphere based on the Chinese Meridian Project”。

摘　　要：Branching structure(BS)is a very important phenomenon in the evolution of equatorial plasma bubbles(EPBs),the mechanism of which is widely studied from observation and from simulation.However,occurrence characteristics of branching structure of equatorial plasma bubbles(BSEPBs)have not been well addressed.In this work,we used seven-years(2012-2018)of observations from two all-sky imagers to study occurrence of BSEPBs in detail.These data reveal a high incidence of BS in EPB cases;in particular,most EPBs occurring on days with geomagnetic disturbances exhibited BS.Periods when all EPBs exhibited BS increased significantly in the 2014 solar maximum.Occurrence times of BSEPBs varied with local time;most of the BSEPBs began to appear between 21:00 and 22:00 LT.During the solar maximum,some BSEPBs were observed after midnight.The data also reveal that BSEPBs are characterized primarily by two branches or three branches.Multi-branching appeared only in the solar maximum.EPB events with different coexisting branching structures increased from 2012 to 2014 and decreased from 2014 to 2018.These results strongly suggest that BSEPB occurrence is related to solar activity and geomagnetic activity,and thus provide a new perspective for future studies of EPBs as well as enriching our understanding of ionospheric irregularity.

关 键 词：branching structure of equatorial plasma bubble equatorial plasma bubble ionospheric irregularity all-sky imager 

分 类 号：P352.7[天文地球—空间物理学]