The dawn−dusk asymmetry in mesosphere and lower thermosphere temperature disturbances during geomagnetic storms at high latitude  

作　　者：GuanChun Wei JianYong Lu Fen Tang JingYuan Li Meng Sun 

机构地区：[1]Institute of Space Weather,School of Atmospheric Physics,Nanjing University of Information Science&Technology,Nanjing 210044,China [2]College of Information and Communication,National University of Defense Technology,Wuhan 430019,China

出　　处：《Earth and Planetary Physics》2024年第2期356-367,共12页地球与行星物理（英文版）

基　　金：the National Key R&D Program of China(Grant No.2022YFF0503702);the National Natural Science Foundation of China(Grant Nos.42004132,42074195 and 42074183);the open funding of the Ministry of Natural Resources Key Laboratory for Polar Science(Grant No.KP202104);the China Geological Survey(Grant No.ZD20220145).

摘　　要：Utilizing observations by the Sounding of the Atmosphere using Broadband Emission Radiometry(SABER)instrument,we quantitatively assessed the dawn-dusk asymmetry in temperature disturbances within the high-latitude mesosphere and lower thermosphere(MLT)during the main phase of geomagnetic storms in this study.An analysis of five geomagnetic superstorm events indicated that during the main phase,negative temperature disturbances were more prevalent on the dawn side than on the dusk side in the high-latitude MLT region.Results of a statistical analysis of 54 geomagnetic storm events also revealed a notable disparity in temperature disturbances between the dawn and dusk sides.At high latitudes,38.2%of the observational points on the dawn side exhibited negative temperature disturbances(less than−5 K),whereas on the dusk side,this percentage was only 29.5%.In contrast,at mid-latitudes,these proportions were 34.1%and 36.5%,respectively,showing no significant difference.We also conducted a statistical analysis of temperature disturbances at different altitudes,which revealed an increase in the proportion of warming disturbances with altitude.Conversely,the proportion of cooling disturbances initially rose with altitude,reaching a peak around 105 km,and subsequently decreased.These temperature disturbance differences could be explained by the day-night asymmetry in vertical wind disturbances during storm conditions.

关 键 词：DAWN dusk asymmetry SABER(Sounding of the Atmosphere using Broadband Emission Radiometry) geomagnetic storms mesosphere and lower thermosphere 

分 类 号：P318.22[天文地球—固体地球物理学]