2004年11月极区中层冬季回波在224MHz的时空特征分析  

Characters of polar mesosphere winter echoes at 224 MHz in November 2004

作　　者：葛淑灿 李海龙[1] 徐彤[2] 陈玉梅[1] 王茂琰[1] GE Shucan;LI Hailong;XU Tong;CHEN Yumei;WANG Maoyan(School of Electronic Science and Engineering,University of Electronic Science and Technology of China,Chengdu 610054,China;National Key Laboratory of Electromagnetic Environment,China Research Institute of Radiowave Propagation,Qingdao 266107,China)

机构地区：[1]电子科技大学电子科学与工程学院,成都610054 [2]中国电波传播研究所电波环境特性及模化技术重点实验室,青岛266107

出　　处：《电波科学学报》2018年第6期717-722,共6页Chinese Journal of Radio Science

基　　金：国家自然科学基金(No.41104097);电波环境特性及模化技术重点实验室基金

摘　　要：在2004年11月9—13日太阳质子事件期间利用224MHz雷达研究了连续五天出现的极区中层冬季回波(polar mesosphere winter echoes,PMWE),发现电离层D区电子密度增强会增大PMWE的产生几率,PMWE强度越大,其持续时间越长,高度范围越大.由于白天D区的电离水平更高,PMWE在白天的出现率很高,在夜晚很低.通过深入分析发现,PMWE与宇宙噪声吸收(cosmic noise absorption,CNA)的极大值存在对应关系,表明PMWE与高能粒子沉降导致的电离层D区电子浓度增强密切相关.同时也发现,极区中层冬季回波和极区中层夏季回波体反射率对频率的依赖性不同,暗示二者的产生机理也可能有所不同.Through researching the polar mesosphere winter echoes(PMWE)of five consecutive days during the solar proton event detected by 224 MHz radar from November 9th to 13th in 2004,we find that the enhancing ionization in D-region can increase the probability of PMWE production,and when intensity of PMWE is greater,the duration is longer and the height range is larger.In addition,the occurrence of PMWE during the days is high vhile the nights is low,because the ionization level of D-region during daytime is higher than night.Moreover,the relation between PMSE and the maximum of cosmic noise absorption(CNA)is analyzed,and we find that the PMSE has a close relation with the increasing electron density in ionosphere D region due to the precipitation of high-energy particle.At the same time,it is found that the polar mesosphere winter echoes and polar mesosphere summer echoes volume reflectivity are different depending on frequency,which may suggest that their mechanism may be different.

关 键 词：太阳质子 极区中层冬季回波 电离层 太阳电磁辐射 宇宙噪声吸收 

分 类 号：O539[理学—等离子体物理]