The first time observations of low-latitude ionospheric irregularities by VHF radar in Hainan  

作　　者：NING BaiQi HU LianHuan LI GuoZhu LIU LiBo WAN WeiXing 

机构地区：[1]Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China [2]Beijing National Observatory of Space Environment,Beijing 102213,China [3]Graduate University of Chinese Academy of Sciences,Beijing 100081,China

出　　处：《Science China(Technological Sciences)》2012年第5期1189-1197,共9页中国科学（技术科学英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 41074113, 40904038, 40774091, 41174136);Chinese Academy of Sciences (Grant No. KZCX2-YW-Y10)

摘　　要：Sanya VHF radar （18.4°N, 109.6°E, dip latitude 12.8°N） at Hainan Island is the first coherent backscatter radar for sounding low-latitude ionospheric irregularities in the mainland of China. In this paper, we present the first results of low-latitude iono- spheric E and F region irregularities using the radar data during the period from February 2009 to March 2010. The Doppler velocity of radar echoes from E region field aligned irregularities （FAIs） was about several tens of meters per second, while the Doppler spectral width was appreciably larger than the velocity, and could reach one hundred meters per second, indicating that the observed E region FAls belonged to type 2 irregularities. The observations of range time intensity （RTI） maps of FAIs showed that E region irregularities most often occurred at night within the altitude range 85-115 kin, and were rarely observed at afternoon hours. The percentage occurrence of E region FAIs maximized during spring months （Feb.-May） with a peak value over 80%. The heights at which the strongest echo related FAIs occurred were mainly around 100 kin, lower than h＇Es and the difference is mostly 10-20 km. December solstice seemed to be the minimum period of occurrence when the FA! ech- oes were commonly detected at a narrow altitude range 90-100 km. Moreover, simultaneous radar and GPS observations dur- ing spread F events in the pre-midnight hours of solar minimum revealed that significant GPS L band scintillations coincided with the appearance of F region plasma plume structures, which extended up to 450 km in altitude.

关 键 词：low-latitude ionosphere ionospheric irregularities VHF radar 

分 类 号：P433[天文地球—大气科学及气象学] TU753.1[建筑科学—建筑技术科学]