The large-scale solar magnetic field and 11-year activity cycles
The large-scale solar magnetic field and 11-year activity cycles
复制标题
大尺度太阳磁场和11年活动周期
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
A. Tlatov
中科院分区：
文献类型：
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作者：
V. Makarov;A. Tlatov
本文分析了1915-1999年太阳Hα磁场天气图，计算了大尺度太阳磁场球谐函数的强度。证明了利用这些Hα图作为研究太阳活动长期变化的数据库的可能性。作为一个例子，比较了1975-1999年斯坦福大学天文台Hα图的磁场极性分布和磁象图的相似极性分布。引入了大尺度磁场的活动指数A（t），它是偶极子和八极分量的磁矩强度之和。大尺度太阳磁场的11年周期平均领先11年的太阳黑子周期5.5年。结果表明，观测到的弱大尺度太阳磁场不是活动区强磁场衰减的产物。根据这些新资料，讨论了当前（第23个）太阳活动周期的水平和太阳活动周期理论的某些方面。
Magnetic Hα synoptic maps of the Sun for 1915–1999 are analyzed and the intensities of spherical harmonics of the large-scale solar magnetic field computed. The possibility of using these Hα maps as a database for investigations of long-term variations of solar activity is demonstrated. As an example, the magnetic-field polarity distribution for the Hα maps and the analogous polarity distribution for the magnetographic maps of the Stanford observatory for 1975–1999 are compared. An activity index A(t) is introduced for the large-scale magnetic field, which is the sum of the magnetic-moment intensities for the dipole and octupole components. The 11-year cycle of the large-scale solar magnetic field leads the 11-year sunspot cycle by, on average, 5.5 years. It is concluded that the observed weak large-scale solar magnetic field is not the product of the decay of strong active-region fields. Based on the new data, the level of the current (23rd) solar-activity cycle and some aspects of solar-cycle theory are discussed.