Probable causes of the abnormal ridge accompanying the 2013-2014 California drought: ENSO precursor and anthropogenic warming footprint
Probable causes of the abnormal ridge accompanying the 2013-2014 California drought: ENSO precursor and anthropogenic warming footprint
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DOI：
10.1002/2014gl059748
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发表时间：
2014-05-16
影响因子：
5.2
通讯作者：
Yoon, Jin-Ho
中科院分区：
文献类型：
--
作者：
Wang, S. -Y.;Hipps, Lawrence;Yoon, Jin-Ho
2013-2014年加州的干旱是由一个异常的高振幅脊系统引发的。利用再分析数据和共同体地球系统模式（CESM）对异常脊进行了研究。结果发现，该脊出现在持续的罗斯贝波能量来源的西北太平洋开始在夏末，随后加强到冬季。该高压脊在下风向产生大量波浪能量，并使美国东北部的低压槽进一步加深。美国，形成偶极子。偶极子和相关的环流模式与厄尔尼诺-南方涛动（ENSO）或太平洋年代际涛动没有直接联系;相反，它与一种ENSO前兆相关。自1970年代以来，偶极子和厄尔尼诺/南方涛动前兆之间的联系变得更强，这是由于CESM模拟的温室气体负荷增加。因此，在2013-2014年冬季异常脊的巨大强度和相关的干旱中，有一个可追溯的人为变暖足迹。
The 2013-2014 California drought was initiated by an anomalous high-amplitude ridge system. The anomalous ridge was investigated using reanalysis data and the Community Earth System Model (CESM). It was found that the ridge emerged from continual sources of Rossby wave energy in the western North Pacific starting in late summer and subsequently intensified into winter. The ridge generated a surge of wave energy downwind and deepened further the trough over the northeast U. S., forming a dipole. The dipole and associated circulation pattern is not linked directly with either El Nino-Southern Oscillation (ENSO) or Pacific Decadal Oscillation; instead, it is correlated with a type of ENSO precursor. The connection between the dipole and ENSO precursor has become stronger since the 1970s, and this is attributed to increased greenhouse gas loading as simulated by the CESM. Therefore, there is a traceable anthropogenic warming footprint in the enormous intensity of the anomalous ridge during winter 2013-2014 and the associated drought.