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

• Main Authors: Nishino, Masanori, Yamagishi, Hisao, Sato, Natuo, Murata, Y., Ruiyuan, Liu, Hongqiao, Hu, Stauning, P., Holtet, J. A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Polar Research Institute of China - PRIC 1999
• Subjects: Arctic; Antarctic; Zhongshan; Zhongshan Station; Danmarkshavn; Advances in Polar Science; Antarc*; Polar Science
• Online Access: http://library.arcticportal.org/2184/; http://library.arcticportal.org/2184/1/A199902007.pdf

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 high-energy 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.