Overall Properties of F Region Around Solar Minimum at Zhongshan Station, Antarctica

• Published in: Chinese Journal of Geophysics
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2000
• Subjects: Zhongshan; Zhongshan Station; Antarc*; Antarctica
• Online Access: http://dx.doi.org/10.1002/cjg2.40; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fcjg2.40; https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1002/cjg2.40

Abstract Based on data of Digisonde Portable Sounder ‐4(DPS‐4) in the years of 1995–1997, we have analyzed the seasonal variations of F region at Zhongshan Station(69.4°S,76.4°E). During the summer time of Zhongshan Station, F‐ region ionization is mainly controlled by the solar ultraviolet radiation. Similar to the phenomena in mid‐latitude area, the value of f oF 2 is changed with local time. During the equinox seasons, soft electron precipitation from the cusp/cleft region seems significant, f 0 F 2 is changed with the magnetic local time, and shows the magnetic noon phenomenon. During the winter time, the sun is under the horizon or have a small elevation angle at Zhongshan Station.So F region is mainly affected by particle precipitation from cusp/cleft region and ionospheric plasma convection as well. Therefore, the diurnal variation of F region maximum critical frequency lies between local noon and magnetic noon. F‐ region occurs all day in summer, and seldom appears at midnight in equinox. In winter, F‐region shows two minimums, one is at midnight and the other is at afternoon cusp. Further analysis of the F region spread indicates that Zhongshan Station passes over the equatorial side of aurora oval at t LT =1600h, and polar side at t LT =2000h.