Warm-air advection, air mass transformation and fog causes rapid ice melt
Warm-air advection, air mass transformation and fog causes rapid ice melt
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DOI：
10.1002/2015gl064373
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发表时间：
2015-07-16
影响因子：
5.2
通讯作者：
Wolfe, Dan
中科院分区：
文献类型：
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作者：
Tjernstrom, Michael;Shupe, Matthew D.;Wolfe, Dan
在东西伯利亚海强烈的暖空气平流期间的直接观测揭示了一个海冰快速融化的时期。白令海峡以北的一个半静止高压系统迫使大陆的暖湿空气向北平流。融化的海冰上方的气团转化形成了强烈的、基于地面的温度逆温，其中形成了浓雾。这导致了地表的长波净辐射为正，而太阳净辐射仅略有减少;逆温还导致了向下的湍流热通量。这些过程的总和增加了表面能量通量的平均约15 Wm（-2）的一个星期。在这一事件前后的卫星图像显示，在受气团转变影响的大片地区，海冰浓度从> 90%下降到接近50%。我们认为，这种快速融化是由大气中的热通量增加，由于暖空气平流触发。
Direct observations during intense warm-air advection over the East Siberian Sea reveal a period of rapid sea-ice melt. A semistationary, high-pressure system north of the Bering Strait forced northward advection of warm, moist air from the continent. Air-mass transformation over melting sea ice formed a strong, surface-based temperature inversion in which dense fog formed. This induced a positive net longwave radiation at the surface while reducing net solar radiation only marginally; the inversion also resulted in downward turbulent heat flux. The sum of these processes enhanced the surface energy flux by an average of similar to 15Wm(-2) for a week. Satellite images before and after the episode show sea-ice concentrations decreasing from > 90% to similar to 50% over a large area affected by the air-mass transformation. We argue that this rapid melt was triggered by the increased heat flux from the atmosphere due to the warm-air advection.