基于COSMIC掩星观测的中国内陆Es分布统计研究  

Statistical research of Es distribution in inland areas of China based on COSMIC occultation observations

作　　者：薛祖祥 袁志刚[1] 刘琨[1,2] 余雄东[1] XUE ZuXiang;YUAN ZhiGang;LIU Kun;YU XiongDong(School of Electronic Information Wuhan University,Wuhan 430072,China;China Research Institute of Radio Wave Propagation,Qingdao 266107,China)

机构地区：[1]武汉大学电子信息学院,武汉430072 [2]中国电波传播研究所,青岛266107

出　　处：《地球物理学报》2018年第8期3124-3133,共10页Chinese Journal of Geophysics

基　　金：国家自然科学基金(41374168;41521063);电波环境特性及模化技术国防科技重点实验室开放基金(20140013)资助

摘　　要：我们采用COSMIC掩星系统提供的2009年1月1日至2010年12月31日的GPS信号信噪比(signal-tonoise ratio,SNR)的观测数据,通过计算SNR数据的归一化标准差对80~130km高度范围内的中国内陆偶发E层(Sporadic E,Es)的空间分布以及垂直厚度等特性进行分析研究,获得了Es发生率的空间分布以及发生率随着季节的变化特征.中国内陆30°N纬线以上区域Es分布随季节变化较为明显,夏季最多,秋季次之,春冬季最少,而南部低纬地区发生率水平常年较高.一般情况下Es主要存在于90~110km高度范围内,但在夏季100km高度以下探测到了较多的Es事件,且主要表现为多层Es结构,可能是由大气重力波引起Es下行运动所致.Es厚度的分布统计表明:大结构Es的厚度分布在2.5~3km范围内存在峰值,小结构Es厚度分布峰值出现在150~200m范围内.We use the signal-to-noise ratio（SNR）data provided by the COSMIC occultation to analyze the distribution of Sporadic E（Es）in inland areas of China.The spatial and vertical thickness distributions of Es in the altitude range of 80~130 km are analyzed by using the normalized standard deviation of SNR data from January 1,2009 to December 31,2010.Then we get the seasonal and spatial distributions of Es occurrence rate derived from the normalized standard deviation.The occurrence rate of Es at latitudes of〉30°N changes significantly with seasons：there is higher occurrence rate in summer,less in autumn,but lowest in spring or winter,while the occurrence rate is perennial high in the low latitude region of China.In general,the Es layers exist mostly between 90 km and 110 km in the E region.However,many events are detected below 100 km in summer,most of them belong to multiple layer structure,which may be attributed to descent ofsporadic E layers caused by the atmospheric gravity waves.In addition,the thickness distribution of large scale Es has its maximum between 2.5 km and 3 km,and small scale Es has its maximum between 150 mand 200 m.

关 键 词：偶发E层 COSMIC 无线电掩星 发生率 

分 类 号：P352[天文地球—空间物理学]