Modeling the global ionospheric total electron content with empirical orthogonal function analysis  

作　　者：WAN WeiXing DING Feng REN ZhiPeng ZHANG ManLian LIU LiBo NING BaiQi 

机构地区：[1]Beijing National Observatory of Space Environment,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China

出　　处：《Science China(Technological Sciences)》2012年第5期1161-1168,共8页中国科学（技术科学英文版）

基　　金：supported by the Special Fund for State Seismology Bureau (Grant No. 201008007);the KIP Pilot Project of CAS (Grant No. YYYT-1110-02);the National Natural Science Foundation of China (Grant Nos. 40974090, 41131066);the National Basic Research Program of China ("973" Project) (Grant No. 2011CB811405)

摘　　要：In the present work we model the global ionospheric total electron content (TEC) with the analysis of empirical orthogonal functions (EOF). The obtained statistical eigen modes, which makeup the modeled TEC, consist of two factors: the eigen vectors mapping TEC patterns at latitude and longitude (or local time LT), and the corresponding coefficients displaying the TEC variations in different time scales, i.e., the solar cycle, the yearly (annual and semiannual) and the diurnal universal time variations. It is found that the EOF analysis can separate the TEC variations into chief processes and the first two modes illustrate the most of the ionospheric climate properties. The first mode contains both the semiannual component which shows the semiannual ionospheric anomaly and the annual component which shows the annual or non-seasonal ionospheric anomaly. The second mode contains mainly the annual component and shows the normal seasonal ionospheric variation at most latitudes and local time sectors. The annual component in the second mode also manifests seasonal anomaly of the ionosphere at higher mid-latitudes around noontime. It is concluded that the EOF analysis, as a statistical eigen mode method, is resultful in analyzing the ionospheric climatology hence can be used to construct the empirical model for the ionospheric climatology.

关 键 词：ionospheric modeling total electron content empirical orthogonal functions 

分 类 号：P468.0[天文地球—大气科学及气象学] P352.5