Regional, seasonal, and inter-annual variations of Antarctic and sub-Antarctic temperature anomalies related to the Mansurov effect
Regional, seasonal, and inter-annual variations of Antarctic and sub-Antarctic temperature anomalies related to the Mansurov effect
复制标题
DOI：
10.1088/2515-7620/ab4a84
复制
发表时间：
2019-10
影响因子：
2.9
通讯作者：
M. Freeman;M. Lam
中科院分区：
文献类型：
--
作者：
M. Freeman;M. Lam
我们使用国家环境预测中心/国家大气研究中心再分析数据表明，南极表面空气温度异常的差异，每日平均黄昏的组成部分，由行星际磁场（IMF）。我们发现，显著异常有很强的地理，季节和年际变化。1999-2002年60°S附近区域异常的代表性峰值振幅在秋季（3.2 °C）-冬季（2.4 °C）-春季（1.6 °C）-夏季（0.9 °C）逐渐减小。利用1999-2002年秋季亚南极地区明显简化的特性，我们证明了这种情况下的温度异常是由于地转风异常，由相同的By变化引起，在7 h时间尺度上，在50和70°S之间的纬向平均气温中，移动空气穿过大的纬向梯度，可以预期By的变化将持续下去。由于引起这些风的对流层压力异常与电离层电势的By-driven异常有关，我们得出结论，IMF引起的全球大气电路的变化可能导致区域地表气温的日常变化高达几摄氏度。
We use National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis data to show that Antarctic surface air temperature anomalies result from differences in the daily-mean duskward component, By, of the interplanetary magnetic field (IMF). We find the statistically-significant anomalies have strong geographical, seasonal, and inter-annual variations. For the interval 1999–2002, regional anomalies poleward of 60°S are of diminishing representative peak amplitude from autumn (3.2 °C) to winter (2.4 °C) to spring (1.6 °C) to summer (0.9 °C). Exploiting apparently simplifying properties in the sub-Antarctic region in autumn 1999–2002, we demonstrate that temperature anomalies in this case are due to geostrophic wind anomalies, resulting from the same By changes, moving air across large meridional gradients in zonal mean air temperature between 50 and 70°S over the 7-hour timescale for which a change in By can be expected to persist. Since the tropospheric pressure anomalies causing these winds have been associated with By-driven anomalies in the electric potential of the ionosphere, we conclude that IMF-induced changes to the global atmospheric electric circuit can cause day-to-day changes in regional surface air temperature of up to several degrees Centigrade.