The discrepancy in solar EUV-proxy correlations on solar cycle and solar rotation timescales and its manifestation in the ionosphere
The discrepancy in solar EUV-proxy correlations on solar cycle and solar rotation timescales and its manifestation in the ionosphere
复制标题
太阳周期和太阳自转时间尺度上的太阳 EUV-代理相关性的差异及其在电离层中的表现
DOI：
10.1029/2011ja017224
复制
发表时间：
2012-03-09
影响因子：
2.8
通讯作者：
Wan, Weixing
中科院分区：
文献类型：
--
作者：
Chen, Yiding;Liu, Libo;Wan, Weixing
这项研究调查了SOHO/Solar EUV监视器26-34 nm EUV与F-10.7和MGII在太阳周期(长期)和太阳自转(短期)时间尺度上的相关性。EUV的长期成分与各指标之间具有很好的相关性，它们之间的一般关系可以通过81天平均的EUV和指标来获取。在太阳活动周期中，短期EUV-Proxy相关性较差且变化较大。短期EUV对代理人的斜率从太阳自转到太阳自转不等，一般低于长期EUV对代理人的斜率。EUV和替代物在主要活动区期间表现出不同的演化，这应该是短期EUV-替代物相关性较差和短期EUV-替代物斜率可变的主要原因。对于26-34 nm的EUV，MG II比F10.7是更好的替代物。它的优势主要来自于短期EUV更好的指标。全球电子含量(GEC)对EUV的长期和短期变化有显著的响应。因此，由于电离层的逐日变化，短期GEC与指标之间的相关性较差，且明显低于短期EUV与指标之间的相关性。GEC代表的短期斜坡亦较长期斜坡为低。F10.7和mg II是通过将它们的每日和81天平均分量与旨在缩小长期和短期极紫外线替代坡度之间差异的加权系数结合在一起而得到改善的。改进后的指标虽然不能解决EUV指标斜率的短期变化，但能有效地提升指标指标的指标。为了更好地指示GEC，该方法也被用来改进代理，但改进后的GEC代理与26-34 nm EUV的代理不同。
This study investigates the correlations between SOHO/Solar EUV Monitor 26-34 nm EUV and the F-10.7 and Mg II proxies on solar cycle (long-term) and solar rotation (short-term) timescales. The long-term components of EUV and proxies are well correlated, and the general relation between them can be captured by the 81 day averaged EUV and proxies. Short-term EUV-proxy correlation is poorer and variable during the solar cycle. The slopes of short-term EUV against proxies vary from solar rotation to solar rotation, and they are generally lower than those of long-term EUV against proxies. EUV and proxies show discrepant evolutions during the episode of major active regions, which should be a primary reason for the poorer short-term EUV-proxy correlation and the variable short-term EUV-proxy slope. Mg II is a better proxy than F10.7 for 26-34 nm EUV. Its superiority mainly comes from better indications for short-term EUV. Global electron content (GEC) significantly responds to the long-term and short-term variations of EUV. Accordingly, the correlations between short-term GEC and proxies are poorer, and they are obviously lower than those between short-term EUV and proxies owing to ionospheric day-to-day variability. Short-term GEC-proxy slopes are also lower than the long-term slopes. F10.7 and Mg II are improved by combining the daily and 81 day averaged components of them with weighted factors that are designed to decrease the difference between long-term and short-term EUV-proxy slopes. The improved proxies can effectively upgrade the indications of proxies for EUV though they cannot solve the variability of short-term EUV-proxy slope. This method is also used to improve proxies for better indicating GEC, but the improved proxies for GEC differ from those for 26-34 nm EUV.