宇宙线强度变化与磁扰K类型

本文把1966—1983年期间发生的679个地磁暴进行了分类,利用统计方法分析了各类磁暴发生前后宇宙线强度的变化特征.突发急始脉冲发生后,宇宙线强度没有出现显著的变化;缓始型暴发生后,宇宙线强度出现Forbush下降,但下降幅度很小;急始型暴发生后,宇宙线强度出现十分明显的Forbush下降.当把急始型暴按K指数大小和持续时间分为5种类型,发现它们伴随的宇宙线Forbush下降是不一样的,其下降幅度随磁暴的增强而加大,下降的速率随磁暴的增强而加快,扰动的持续时间随磁暴的减弱而增加. 

The Variations of Galactic Cosmic Ray Intensity and the K Category of Magnetic Disturbances

The relationship between the variations of galactic cosmic ray intensity and geomagnetic storms from 1966 to 1983 is studied in this paper. The variations of the cosmic ray intensity during a sudden commencement pulse Si doesn't show an obvious decrease. Avery small Forbush decrease appears during gradual commencement storm G_c. On the other hand, there is a very obvious Forbush decrease during sudden commencement storm S_c. Then S_c storms are classified into S_A, S_B, S_D. S_d and S_b storms on the basis of Kindex. The results of analysis show that Forbush decrease of cosmic ray intensity during S_A storms is the most obvious and the decreasing rate and recovering rate are also the fastest. The amplitutes of Forbush decrease are descending in the order of S_A, S_B S_Dand S_d storms. Their decreasing rates and recovering rates become slowing in the same order. But the cosmic ray intensity during S_b storms has no obvious decrease. According to corresponding relationship between Kcategory of magnetic disturbances and. interplanetary disturbances, a relation between cosmic ray intensity variations and interplanetary disturbances is obtained.