Abstract: Based on the IDP data from French DEMETER satellite,the global distribution is shown,which corresponds to three precipitation zones:auroral precipitation zone,mid-high latitude precipitation zone and South Antarctic precipitation zone.Then the Chili earthquake with M8.8 on February 27,2010 is taken as an example.The IDP fluxes from repeated orbits are compared and the results show that there is a clear enhancement on February 26,just one day ahead of the Chili earthquake.In the south zone with L = 2.1 ～ 2.7,the flux on February 26 is higher than that on other days before.While in the north zone with L = 2.1 ～ 2.7,there is no clear change in the day time but a great enhancement during the night,which is close to the earthquake occurrence time.At the same time,the flux on February 26 over the epicenter is far lower than that on other days before during the day time while it reaches the peak at night.

Key words: Chili earthquake, DEMETER, IDP flux, energetic particles, repeated orbits

摘要： 利用法国DEMETER卫星IDP载荷观测的高能粒子通量数据,首先研究了其全球表现特征,即极区沉降带、中高纬沉降带和南大西洋沉降区。进而以2010年2月27日发生的智利8.8级地震为例,通过重访轨道的对比,发现高能粒子通量在2月26日出现了比较显著的变化:即南纬L=2.1～2.7一直增强,而其共轭区,即北纬L=2.1～2.7时,在26日白天无显著变化,只是在接近地震发生时才出现共轭效应。同时,在26日白天震中上空靠近赤道地区粒子通量显著降低,而到夜晚在震中区上空及附近地区粒子通量显著增强。在震后粒子通量恢复正常水平。

关键词: 智利地震, DEMETER, IDP通量, 高能粒子, 重访轨道