Chinese Journal of Polar Research

ADVANCES IN POLAR SCIENCE ›› 1999, Vol. 10 ›› Issue (2-English): 125-132.

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Post-noon ionospheric absorption observed by the imaging riometers at polar cusp/cap conjugate stations

M. Nishino1, H. Yamagishi2, N. Sato2, Y. Murata3, Liu Ruiyuan4, Hu Hongqiao4,5, P. Stauning6 and J. A. Holtet7   

  1. 1 Solar-Terrestrial Environment Laboratory, Nagoya University, Toyokawa 442, Japan;
    2 National Institute of Polar Research, Tokyo 173, Japan;
    3 Graduate University of Advanced Studies, Tokyo 173, Japan;
    4 Polar Research Institute of China, Shanghai 200129, China;
    5 Department of Radio Science and Technology, Wuhan University, Wuhan 430072, China;
    6 Danish Meteorological Institute, Copenhagen DK-2100, Denmark;
    7 University of Oslo, Oslo N-0316, Norway
  • Online:1949-06-30 Published:1949-06-30
  • Contact: M. Nishino

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Abstract:

An example of post-noon ionospheric absorption observed by the imaging riometers at Ny-Alesund/Danmarkshavn in the arctic region and Zhongshan Station in Antarctic is presented. The post-noon absorption observed simultaneously between the hemispherical stations was a spike-type with weak intensity (<1 dB) during the high solar wind dynamic pressure. The absorption spikes might be caused by precipitation of highrenergy electrons (30 - 300 keV) in the closed dayside magnetosphere. It should be noted that the precipitation region of the absorption spike associated with the steep pressure increase (~ 13 nPa) was localized and shifted equatorward.

Key words: post-noon ionospheric absorption, conjugate imaging riometer, high solar wind dynamic pressure