A new topside profiler based on Alouette/ISIS topside sounding

作者:Zhu, Jie; Zhao, Biqiang*; Wan, Weixing; Ning, Baiqi; Zhang, Shunrong
来源:Advances in Space Research, 2015, 56(10): 2080-2090.
DOI:10.1016/j.asr.2015.08.008

摘要

A new empirical model of the topside ionospheric density was developed to describe the measured topside profile accurately. This profiler is a composite of two separate layers of different ion species in the topside ionosphere, the O+ layer and the light-ions (H+ and H+) layer. The light-ions layer is characterized by an alpha-Chapman function with a linearly increasing scale height with altitude. This new model appears to perform the best as compared to five other typical topside profilers in representing data from ISIS-1&2 and Alouette-1&2 observations. We also analyzed the magnetic latitude dependence, seasonal variation, and day night difference of the characteristic parameters of the light-ions layer during the magnetic quiet (Kp < 4) and low solar activity (f107 < 120 solar flux unit, sfu) period within magnetic latitudes from -60 degrees to 90 degrees. The statistical results show the expected different behaviors of light-ions and O+ parameters. In addition, the portion of the light-ion components contributing to the topside-ionospheric total electron content (TTEC) was studied also. The results suggest that the light ions make a great contribution to the TTEC, especially in magnetic low- and middle-latitudes at night.