17 GHz活动区域编号
The 17 GHz active region number
摘要：
我们报告了在1992年，第22周的最大值附近和2013年之间，使用野边山射电日像仪在17 GHz观测到的活动区域（NAR）数量的统计数据，其中还包括第24周的最大值，并与其他活动指标进行了比较。我们发现NAR极小值比太阳黑子数（SSN）和10.7cm（F10.7）处射电通量的极小值要短。这种较短的NAR最小值可以反映由微弱磁场或无斑点区域产生的活动区域的存在，这些区域是计数的活动区域的相当大的一部分。太阳射电指数F10.7/NAR之间的比值在分析的两个极小期期间显示出类似的减小，这与第23-24周极小期期间两个射电指数与SSN之间的比值的增加形成对比。这些结果表明，射电指数对1500 G量级的弱磁场比形成太阳黑子所必需的磁场更敏感。对活动区亮温月平均值的分析表明，它的长期变化模拟了太阳活动周期，尽管由于陀螺共振发射，在最高温度研究中观察到了大量的强烈尖峰。在当前周期24期间，这些尖峰在数量上的减少也是明显的，这是过去几年太阳黑子磁场减弱的结果。
英文摘要：
We report the statistics of the number of active regions (NAR) observed at 17 GHz with the Nobeyama Radioheliograph between 1992, near the maximum of cycle 22, and 2013, that also includes the maximum of cycle 24, and we compare with other activity indexes. We find that NAR minima are shorter than those of the sunspot number (SSN) and radio flux at 10.7 cm (F10.7). This shorter NAR minima could reflect the presence of active regions generated by faint magnetic fields or spotless regions, which were a considerable fraction of the counted active regions. The ratio between the solar radio indexes F10.7/NAR shows a similar reduction during the two minima analyzed, which contrasts with the increase of the ratio of both radio indexes in relation to the SSN during the minimum of cycle 23-24. These results indicate that the radio indexes are more sensitive to weaker magnetic fields than those necessary to form sunspots, of the order of 1500 G. The analysis of the monthly averages of the active region brightness temperatures shows that its long term variation mimics the solar cycle, although, due to the gyro-resonance emission, a great number of intense spikes are observed in the maximum temperature study. The decrease, in number, of these spikes is also evident during the current cycle 24, a consequence of the sunspot magnetic field weakening in the last years.
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