Cosmic ray density gradients related to north‐south asymmetry in activity on the Sun
Cosmic ray density gradients related to north‐south asymmetry in activity on the Sun
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与太阳活动南北不对称相关的宇宙射线密度梯度
DOI：
10.1029/ja091ia03p02943
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
J. Humble
中科院分区：
文献类型：
--
作者：
D. B. Swinson;M. Shea;J. Humble
给出了1965 - 1983年北方和南方半球地下宇宙线望远镜观测的数据，分析了行星际磁场（IMF）感度的函数，以考察垂直于黄道面的宇宙线密度梯度的长期性质。每年宇宙线太阳日变化矢量IMF（B）远离和朝向太阳，这些矢量包括从B × Np各向异性的贡献，从其中的垂直梯度，Np的主要方向推断。这些数据进行了比较，南北不对称的活动在同一时期的太阳，根据全面的耀斑指数数据和太阳活动与II型无线电发射。直到1969-1971年太阳极场反转的宇宙线数据与两半球望远镜观测到的指向南方的垂直宇宙线梯度一致。太阳活动数据表明，从1959年到1970年，太阳北方半球的活动在统计上显著过剩，这很可能是这一时期宇宙射线垂直梯度向南的原因。在1969-1971年的逆转之后，太阳活动数据在两个太阳半球之间变得合理对称。北方半球的宇宙射线数据显示了1971年后宇宙射线向北倾斜的一些证据，而南半球望远镜的数据则继续表明宇宙射线向南倾斜。如果合成的垂直宇宙射线梯度是两个梯度之和，那么这些结果就可以得到解释--一个是南北对称的梯度，它在太阳极地磁场反转时反转，另一个是由于太阳活动的南北不对称性而产生的更大的南北不对称梯度，沿着。
Data are presented from underground cosmic ray telescopes in both the northern and southern hemispheres from 1965 to 1983, analyzed as a function of interplanetary magnetic field (IMF) sense, to examine the long-term properties of the cosmic ray density gradient perpendicular to the ecliptic plane, ▽Np. Yearly cosmic ray solar diurnal variation vectors for IMF (B) away from and toward the sun are obtained; these vectors include a contribution from the B × ▽Np anisotropy, from which the predominant direction of the perpendicular gradient, ▽Np, is inferred. These data are compared with the north-south asymmetry in activity on the sun for the same period, based both on comprehensive flare index data and on solar events associated with type II radio emission. The cosmic ray data up to the 1969–1971 solar polar field reversal are consistent with a perpendicular cosmic ray gradient pointing southward, observed by telescopes in both hemispheres. The solar activity data indicate a statistically significant excess of activity in the sun's northern hemisphere from 1959 through 1970, which may well be the cause for this southward perpendicular cosmic ray gradient during this period. After the 1969–1971 reversal the solar activity data become reasonably symmetrically divided between the two solar hemispheres. The northern hemisphere cosmic ray data show some evidence of a northward pointing cosmic ray gradient after 1971, while data from the southern hemisphere telescopes continue to indicate a southward pointing gradient. These results can be accounted for if the resultant perpendicular cosmic ray gradient is the sum of two gradients—a north-south symmetric gradient that reverses upon reversal of the sun's polar magnetic field, along with a larger north-south asymmetrical gradient that is due to north-south asymmetry in activity on the sun.