Role of ocean evaporation in California droughts and floods
Role of ocean evaporation in California droughts and floods
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DOI：
10.1002/2016gl069386
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发表时间：
2016-06
影响因子：
5.2
通讯作者：
Jiangfeng Wei;Q. Jin;Zong‐Liang Yang;P. Dirmeyer
中科院分区：
文献类型：
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作者：
Jiangfeng Wei;Q. Jin;Zong‐Liang Yang;P. Dirmeyer
自2011年冬季以来，加州发生了创纪录的干旱。研究发现，干旱主要是由美国西海岸的持续高压系统造成的，该系统与太平洋海面温度异常有关。与干旱和洪水有关的水循环仍然没有得到清楚的了解。在这里，我们表明，西海岸的大气环流不仅控制大气的收敛和降水的形成，但也在很大程度上决定了地面风速，这进一步影响了蒸发在北太平洋东部，主要蒸发水汽源加州降水。由于这一机制，在最近的干旱期间，北太平洋东部的海洋蒸发量减少了。然而，海洋蒸发异常对加州降水的直接影响很小，特别是在干旱年份，主要是因为它们的振幅很弱。加州的干旱不能简单地归因于海洋蒸发的减少。太平洋蒸发量的增加与加州上空的洪水之间的联系更强一些。
Since winter 2011, a record‐breaking drought has occurred in California. Studies found that the drought is mainly caused by a persistent high‐pressure system off the U.S. West Coast, which is linked to Pacific sea surface temperature anomalies. The water cycles associated with the droughts and floods are still not clearly understood. Here we show that the atmospheric circulation off the West Coast not only controls the atmospheric convergence and formation of precipitation but also largely determines surface wind speed, which further affects the evaporation over the eastern North Pacific, the major evaporative moisture source for California precipitation. Because of this mechanism, the ocean evaporation over the eastern North Pacific has been reduced during the recent drought. However, the ocean evaporation anomalies have little direct influence on California precipitation, especially during dry years, mainly because of their weak amplitudes. The California droughts cannot be readily attributed to the reduced ocean evaporation. The association between increased Pacific evaporation and floods over California is somewhat stronger.