漂移壳追踪方法与内辐射带的长期变化

地磁场的长期变化发迹辐射带结构，如何在当前年代下恰当地使用ＡＥ－８／ＡＰ－８模型，目前国内外对此问题存在着很大的争议。我们在物理分析的基础上给出了当前年代下使用辐射带模型ＡＰ－８的漂移壳追踪方法ＤＳＴＭ（Ｄｒｉｆｔ Ｓｈｅｌｌ Ｔｒａｃｉｎｇ Ｍｅｔｈｏｄ）。计算结果表明地磁场的长期变化对内辐射带的通量分布有着显著的影响。３０－４０年来，南大西洋通量异常区中心向丁和向北发生偏移，高粒子辐射区域的范

DRIFT SHELL TRACING METHOD AND THE SECULAR VARIATION OF INNER RADIATION FLUXE

The AE-8/AP-8 models, which were constructed by NASAwith satellite observation data in the 1960s and 1970s, have long beenconsidered to be the standard trapped radiation models. It seems thatthey will continuously be used for a certain period of time in thefuture. The weakening of the geomagnetic field causes the drift shell ofa charged particle to descend and the structure of the Trapped RadiationBelt to deform. Thus it is of importance to correctly use the AE-8/AP-8models in the contemporary era. However, up to now there seems to be noconsensus on this issue. On the basis of physical analysis, we proposethe Drift Shell Tracing Method (DSTM) in this paper to solve theproblem. The DSTM provides a reasonable way to apply the standardtrapped radiation models within the adiabatic approximation. Thecalculation results indicate that the change of the geomagnetic fieldplays a significant role in the particle redistribution in the innerzone. It is found that in the past three decades ,the central locationof the particle South Atlantic Anomaly (SAA) has drifted westward almost20 in longitude and northward almost 10 in latitude. In thealtitudes of 300-400 kilometers, the intensity of proton fluxes hasvaried dramatically and the flux difference at the same location caneven be up to 3-4 orders of magnitude.