The ionospheric responses to two strong storms on 17-19 August 2003 and 22-23 January 2004 are studied,using the data from Irkutsk(52.5°N,104°E) and Hainan(19.5°N,109°E) ionospheric stations.The an...The ionospheric responses to two strong storms on 17-19 August 2003 and 22-23 January 2004 are studied,using the data from Irkutsk(52.5°N,104°E) and Hainan(19.5°N,109°E) ionospheric stations.The analysis of variations in relative deviations of the critical frequency △f_0F_2 revealed that at middle latitudes(Irkutsk) negative disturbances were observed in the summer ionosphere; positive and negative ones,in the winter ionosphere during the main and recovery phases respectively.At low latitudes(Hainan),the disturbances were positive in all the cases considered. Mechanisms of the disturbances were analyzed with the aid of empirical models of the neutral atmosphere NRLMSISE-00 and thermospheric wind HWM07.The main factors determining △f_0F_2 variations at middle latitudes during the storms were demonstrated to be the disturbed equatorward thermospheric wind transporting the disturbed atmospheric composition,the increase in the atomic oxygen concentration,and the passage of internal gravity waves.At low latitudes,the effects associated with neutral composition variations are less significant than those of the thermospheric wind and electric fields.展开更多
基金Supported by the Russian Foundation for Basic Research(11-05-91153,11-05-00908)Program of the Division of EarthSciences,Russian Academy of Sciences(No.8)+1 种基金National Natural Science Foundation of China(41274146,41074114)the Specialized Research Fund for State Key Laboratory of China
文摘The ionospheric responses to two strong storms on 17-19 August 2003 and 22-23 January 2004 are studied,using the data from Irkutsk(52.5°N,104°E) and Hainan(19.5°N,109°E) ionospheric stations.The analysis of variations in relative deviations of the critical frequency △f_0F_2 revealed that at middle latitudes(Irkutsk) negative disturbances were observed in the summer ionosphere; positive and negative ones,in the winter ionosphere during the main and recovery phases respectively.At low latitudes(Hainan),the disturbances were positive in all the cases considered. Mechanisms of the disturbances were analyzed with the aid of empirical models of the neutral atmosphere NRLMSISE-00 and thermospheric wind HWM07.The main factors determining △f_0F_2 variations at middle latitudes during the storms were demonstrated to be the disturbed equatorward thermospheric wind transporting the disturbed atmospheric composition,the increase in the atomic oxygen concentration,and the passage of internal gravity waves.At low latitudes,the effects associated with neutral composition variations are less significant than those of the thermospheric wind and electric fields.
