A modeling study of the ionospheric equatorial anomaly based on the FormoSat-3/COSMIC data

• Main Authors: Jyun-Ying Huang, 黃俊穎
• Other Authors: Lung-Chih Tsai
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/er73ke

碩士 === 國立中央大學 === 太空科學研究所 === 97 === The TaiWan Ionospheric Model (TWIM) is a numerical and phenomenological model of global ionospheric electron density (Ne) and is constructed from monthly-weighted and hourly vertical Ne profiles retrieved from FormoSat3/COSMIC GPS radio occultation measurements. TWIM can also provide global F2-layer critical frequency (foF2), peak density height (hmF2), and scale height (HF2) maps to study features of equatorial ionospheric anomaly (EIA). The modeling study investigates the diurnal and seasonal variations of EIA and specifically attempts to account for the latitudinal and longitudinal structures. This paper also shows that the neutral winds could cause the north-south asymmetries and longitudinal variation. Furthermore, the phenomena of EIA were also varied with the solar activity. The foF2 values in 2007 are higher than those in 2008 generally, with the exception in March. This variation and exception match to the different of the observational sunspot number between 2007 and 2008.