F-region electron density depletions associated with main ionization troughs in the high-latitude ionosphere are studied using EISCAT CP3 data of meridian scanning experiments. The troughs in our observations are foun...F-region electron density depletions associated with main ionization troughs in the high-latitude ionosphere are studied using EISCAT CP3 data of meridian scanning experiments. The troughs in our observations are found to appear mainly in dusk sector, extending from late afternoon to pre-midnight, with higher occurrence rate during equinox and winter. Simultaneous ion drift velocity inF-region shows that the main trough minimum is mostly located at the equator ward edge of the plasma convection flow, rather than in the region where the largest ion flow are observed.展开更多
Ionograms taken from a Digisonde Portable Sounder (DPS 4) at Zhongshan Station of Antarctica in 1995 are used to analyse the mean ionospheric properties in winter. The F region is rather unstable in winter and has la...Ionograms taken from a Digisonde Portable Sounder (DPS 4) at Zhongshan Station of Antarctica in 1995 are used to analyse the mean ionospheric properties in winter. The F region is rather unstable in winter and has large diurnal variation. The monthly medium value of f oF 2 has a main peak around 0900UT when maximum value occurs and a sub peak between 1300 1500UT. It may be affected synthetically by the low energy electron precipitation in cusp region, the high latitude plasma convection and the solar radiation, resulted in so called F region magnetic noon phenomena. Low values of f oF 2 occur in post midnight (2000 0100UT) when Zhongshan Station crosses the ionospheric polar hole. Sporadic E layer which caused mostly by auroral particle precipitation can be observed almost every day with the highest value of f oE s around 1700UT. The diurnal variation of E layer is relatively smooth.展开更多
基金Supported by the National Natural Science Foundation of China!(496 74241) the Research Fund for the DoctoralProgram of Hi
文摘F-region electron density depletions associated with main ionization troughs in the high-latitude ionosphere are studied using EISCAT CP3 data of meridian scanning experiments. The troughs in our observations are found to appear mainly in dusk sector, extending from late afternoon to pre-midnight, with higher occurrence rate during equinox and winter. Simultaneous ion drift velocity inF-region shows that the main trough minimum is mostly located at the equator ward edge of the plasma convection flow, rather than in the region where the largest ion flow are observed.
文摘Ionograms taken from a Digisonde Portable Sounder (DPS 4) at Zhongshan Station of Antarctica in 1995 are used to analyse the mean ionospheric properties in winter. The F region is rather unstable in winter and has large diurnal variation. The monthly medium value of f oF 2 has a main peak around 0900UT when maximum value occurs and a sub peak between 1300 1500UT. It may be affected synthetically by the low energy electron precipitation in cusp region, the high latitude plasma convection and the solar radiation, resulted in so called F region magnetic noon phenomena. Low values of f oF 2 occur in post midnight (2000 0100UT) when Zhongshan Station crosses the ionospheric polar hole. Sporadic E layer which caused mostly by auroral particle precipitation can be observed almost every day with the highest value of f oE s around 1700UT. The diurnal variation of E layer is relatively smooth.
