研究華衛一號（福衛一號）量測到的離子密度分佈圖，是否在2000 年及 2002 年當太陽輻射量一樣大時，全球四季的變化都大同小異，這是用來証明太陽的輻射質量決定電離層密度分佈的重要因素。再者研究四季中，春秋及夏冬兩個不同型態的季節，對電離層日、夜的變化，是否有顯著的區別。我們也將以電離層赤道異常區的峰、谷比值是否與日落後密度不規體發生機率有顯著的關係。 Seasonal and longitudinal (s/l) variations of ion density structure at the 600-km low-latitude ionosphere observed by ROCSAT-1 between two similar solar activity years of 2000 and 2002 are examined at five different local-time (LT) sectors. A reproducibility of density structure will be examined under similar solar flux input, including the shape of equatorial ionization anomaly (EIA) structure. The model result from either the 2006 International Reference Ionosphere (IRI) model or the thermosphere ionosphere electrodynamics general circulation model (TIEGCM) will be used to compare with the ROCSAT observed global/seasonal/local-time variations of ionospheric structure. Furthermore, the ROCSAT observed s/l variations of crest-to-trough ratio in the EIA structure will be studied for the correlation with the s/l variations of the post-sunset irregularity occurrence rates. 研究期間 : 9808 ~ 9907
