A detailed investigation of low latitude tweek atmospherics observed by the WHU ELF/VLF receiver:2.Occurrence features and associated ionospheric parameters  

作　　者：Juan Yi XuDong Gu Wen Cheng XinYue Tang Long Chen BinBin Ni RuoXian Zhou ZhengYu Zhao Qi Wang LiQing Zhou 

机构地区：[1]Department of Space Physics,School of Electronic Information,Wuhan University,Wuhan 430072,China [2]State Key Laboratory of Space Weather,Chinese Academy of Sciences,Beijing 100190,China

出　　处：《Earth and Planetary Physics》2020年第3期238-245,共8页地球与行星物理（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grants Nos. 41674163, 41474141, 41204120,41304127, 41304130, and 41574160);the Projects funded by China Postdoctoral Science Foundation (Grants Nos. 2013M542051, 2014T70732);the Hubei Province Natural Science Excellent Youth Foundation (2016CFA044);The project Supported by the Specialized Research Fund for State Key Laboratories;the 985 funded project of School of Electronic information, Wuhan University。

摘　　要：As a companion paper to Zhou RX et al.(2020),this study describes application of the automatic detection and analysis module to identify all the tweek atmospherics detectible in the WHU ELF/VLF receiver data collected at Suizhou station during the period of 3 February through 29 February 2016.Detailed analysis of the identified low-latitude tweek events reveals that the occurrence rate varies considerably—from 800 to 6000 tweeks per day,and exhibits a strong diurnal and local time dependence,the peak occurring before local midnight.The diurnal variation of identified tweeks was similar to that of the lightning data obtained by the World-Wide Lightning Location Network(WWLLN)..Estimates of the propagation distance and ionospheric reflection height of tweek atmospherics suggest that the majority(~92%)of the low latitude tweeks originate from the lightning activity within a radius of 4000 km and that they are very likely to reflect from the lower ionospheric D-region at the height range of 75–85 km.At these lower ionospheric reflection altitudes,~74%of the corresponding electron densities from the tweek spectral measurements are within 24.5–27.5 cm^-3.The daily variation of estimated D-region electron densities in the considered period(February 2016)also exhibits a small overall increasing trend from early to later in the month.

关 键 词：ionospheric D-region electron density tweek atmospherics 

分 类 号：P412[天文地球—大气科学及气象学]