自外輻射帶沉降的高能電子會對地球高層大氣及中高緯的底層電離層(D層及E層)造成嚴重的影響。持續幾天之久的強沉降現象發生於反覆磁暴期間，並會造成電離層全球性的擾動，而這些沉降是由於外輻射帶電子受到持續強磁副暴及波動的作用，進而有效加速與散射後所造成的結果。反覆磁暴主要發生於第24太陽活動週期的衰退時期。本計畫欲研究2015-2018年外輻射帶的動力學，以決定電子沉降與外輻射帶的電子來源及損失之間的關係。我們將使用高遠地點、低傾角的台日Arase及NASA RBSP衛星資料來研究外輻射帶，另將使用NOAA POES的觀測鏈及低軌道、高傾角的DMSP衛星來分析自外輻射帶沉降的高能電子。本計畫的研究成果預計將能提供磁層-電離層-大氣層耦合的新見解，亦將有助於改進反覆磁暴期間的電離層擾動預報。 ;Precipitation of energetic electrons from the outer radiation belt (ORB) affects significantly the upper atmosphere and the bottomside ionosphere (D and E layers) at middle to high latitudes. Long-lasting (days) intense precipitations occur during recurrent magnetic storms and disturb the ionosphere globally. The precipitations result from effective acceleration and scattering of electrons in the ORB due to long-lasting intense substorm and wave activity. The recurrent geomagnetic storms dominate during the declining phase of the 24th solar cycle. It is proposed to study the dynamics of ORB during the years 2015 – 2018 in order to determine the electron precipitations as a function of electron sources and losses in the ORB. The heart of ORB will be investigated using experimental data acquired from joint Taiwan-Japan Arase mission and NASA RBSP, the high-apogee spacecraft of low inclination. The precipitation of energetic electrons from ORB will be analyzed using a fleet of NOAA POES and DMSP satellites located at low-altitude orbits of high inclination. The results of study will provide a new insight to the magnetosphere-ionosphere-atmosphere coupling that will help to improve the prediction of ionospheric disturbances during recurrent magnetic storms.
