|
|
 |
|
|
Ann. Geophys., 23, 2961-2966, 2005
www.ann-geophys.net/23/2961/2005/
© European Geosciences Union 2005
A statistical study on the correlations between plasma sheet and solar wind based on DSP explorations
G. Q. Yan1,2, C. Shen1, Z. X. Liu1, C. M. Carr3, H. Rème4, and T. L. Zhang5
1Key Laboratory of Space Weather, Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100080, China
2Graduate School of Chinese Academy of Sciences, No. 19 Jia, Yu Quan Road, Beijing 100039, China
3Imperial College of Science, Technology and Medicine, London, UK
4CESR, BP4346, 31 028 Toulouse Cedex 4, France
5Space Research Institute, Austrian Academy of Sciences, Graz, Austria
Abstract. By using the data of two spacecraft, TC-1 and ACE
(Advanced Composition Explorer), a statistical study on the correlations
between plasma sheet and solar wind has been carried out. The results
obtained show that the plasma sheet at geocentric distances of about
9~13.4 Re has an apparent driving relationship with the solar wind. It is found
that (1) there is a positive correlation between the duskward component of
the interplanetary magnetic field (IMF) and the duskward component of
the geomagnetic field in the plasma sheet, with a proportionality constant of about
1.09. It indicates that the duskward component of the IMF can effectively
penetrate into the near-Earth plasma sheet, and can be amplified by sunward
convection in the corresponding region at geocentric distances of about
9~13.4 Re; (2) the increase in the density or the dynamic pressure of
the solar wind will generally lead to the increase in the density of the
plasma sheet; (3) the ion thermal pressure in the near-Earth plasma sheet is
significantly controlled by the dynamic pressure of solar wind; (4) under
the northward IMF condition, the ion temperature and ion thermal pressure in
the plasma sheet decrease as the solar wind speed increases. This feature
indicates that plasmas in the near-Earth plasma sheet can come from
the magnetosheath through the LLBL. Northward IMF is one important condition for the
transport of the cold plasmas of the magnetosheath into the plasma sheet through
the LLBL, and fast solar wind will enhance such a transport process.
Full Article in PDF (522 KB) |
|
|
