HR: 0800h
AN: SA31A-0339    [Abstracts]
TI: A theoretical study of the ionosphere over Zhongshan Station, Antarctica
AU: * Zhang, B
EM: bczhang@pric.gov.cn
AF: Polar Research Institute of China, 451 Jinqiao Road, Shanghai, 200136 China
AU: Liu, R
EM: ryliu@vip.sina.com
AF: Polar Research Institute of China, 451 Jinqiao Road, Shanghai, 200136 China
AU: Yang, H
EM: huigen_yang@pric.gov.cn
AF: Polar Research Institute of China, 451 Jinqiao Road, Shanghai, 200136 China
AU: Chen, Z
EM: skychen@pric.gov.cn
AF: Polar Research Institute of China, 451 Jinqiao Road, Shanghai, 200136 China
AB: A three-dimensional, time-dependent model for the polar ionosphere has been developed. The simulation results are applied to the interpretation of the ionospheric F region over Zhongshan Station. The daily variation is obtained for the high-latitude global polar ionosphere NmF2, mainly taking into account the interaction between the solar EUV ionization and the ionospheric convection processes in the polar region. It has been found that, after comparison between the simulation and observation at ZhongShan station (69.4S,76.4E), Antarctica, the southern polar F region ionosphere is mainly controlled by the ionospheric convection in southern winter and equinox seasons. The daily trend of NmF2 is determined by the interaction between solar EUV ionization and the plasma convection at high latitudes. In southern winter, the peak of NmF2 observed in the daily variation at Zhongshan Station results from the unique location of Zhongshan Station. While Zhongshan station is moving toward the dayside, high density plasma existing at lower latitudes due to sunlit ionization is transported into higher latitudes, forming the tongue of ionization (TOI) structure. Zhongshan station moves right under this TOI structure which has been fully structured at about 0900 UT, a time in terms of which the simulation shows well agreement with the observation. During southern equinox, NmF2 over Zhongshan station is influenced by the dawn convection from 0000 to 0600 UT. The daily variation of NmF2 in the simulation agrees well with that observed over Zhongshan station. It has also been found that the variation of NmF2 is related to interplanetary magnetic field (IMF) By component. While IMF By<0, there exists westward convection component at the gemagnetic latitude of Zhongshan station. NmF2 reaches less abruptly at its peak value in its daily variation. Contributions from both precipitation and convection to F region ionosphere over Zhongshan are analyzed.
DE: 2437 Ionospheric dynamics
DE: 2447 Modeling and forecasting
SC: SPA-Aeronomy [SA]
MN: Fall Meeting 2005