The total solar eclipse of December 14, 2020 in southern South America and its effects on atmospheric variables
The total solar eclipse of December 14, 2020 in southern South America and its effects on atmospheric variables
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2020年12月14日南美洲南部日全食及其对大气变量的影响
DOI：
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发表时间：
2021
影响因子：
8.9
通讯作者：
R. Saurral
中科院分区：
文献类型：
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作者：
Franco M. Piscitelli;R. Saurral
2020年12月14日，南美洲南部发生日全食。它发生在接近南半球夏至和中午前后，为研究太阳入射辐射突然减少对不同大气变量的影响提供了几乎理想的条件。有趣的是，这一天文现象移动的区域当时正受到冷锋的影响，冷锋伴随着大量的云量和冷空气平流到达该地区。因此，本影区域表面温度的实际下降是由辐射效应（即由于日食本身造成的太阳辐射减少）和与冷空气注入有关的环流效应共同作用的结果。本文提供了对整个温度变化的两种影响的量化，并讨论了潜在的机制和由冷却引起的对地面风的相关影响。结果表明，在远离本影的地区，与日全食相关的温度下降可能与本影内的温度一样高（甚至更高），这取决于当时的天气条件。
A total solar eclipse affected southern South America on December 14, 2020. Its occurrence close to the summer solstice in the Southern Hemisphere and around noon brought almost ideal conditions to study the effects of the sudden reduction in incoming solar radiation on different atmospheric variables. Interestingly, the astronomical phenomenon moved over a region that at that time was being affected by a cold front accompanied by significant cloudiness and cold air advection to the area. Therefore, the actual drop in surface temperature over the umbra region resulted from a combination of the radiative effect (i.e., the reduction in solar radiation due to the eclipse itself) and a circulation effect related to the injection of colder air. A quantification of both effects on the full temperature variation is provided, along with a discussion on the underlying mechanisms and the related effects on surface winds derived from the cooling. Results show that temperature drops associated with total solar eclipses in areas far away from the umbra can be as high as (or even higher than) those within the umbra, depending on the prevailing weather conditions.