The influence of stratospheric vortex displacements and splits on surface climate
The influence of stratospheric vortex displacements and splits on surface climate
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DOI：
10.1175/jcli-d-12-00030.1
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发表时间：
2013-04
影响因子：
4.9
通讯作者：
D. Mitchell;L. Gray;J. Anstey;M. Baldwin;A. Charlton-Perez
中科院分区：
文献类型：
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作者：
D. Mitchell;L. Gray;J. Anstey;M. Baldwin;A. Charlton-Perez
平流层变率与地球表面异常天气模式之间存在着密切的联系。具体来说，在北极极地涡旋的极端变化期间，被称为“弱涡旋事件”，异常可以在数周的时间尺度上从平流层上层下降到地面。随后，在北部高纬度地区出现了冷空气事件的爆发，大西洋和西欧地区的地表温度也出现了四极模式，但目前尚不清楚为什么某些事件下降到地表，而另一些事件却没有。本研究比较了一种基于位涡分布的弱涡旋事件分类新方法与现有方法，并证明将弱涡旋事件细分为涡旋位移和涡旋分裂对周-月时间尺度对流层天气模式具有重要意义。利用再分析数据发现，涡旋分裂事件与涡旋分裂事件有关。
AbstractA strong link exists between stratospheric variability and anomalous weather patterns at the earth’s surface. Specifically, during extreme variability of the Arctic polar vortex termed a “weak vortex event,” anomalies can descend from the upper stratosphere to the surface on time scales of weeks. Subsequently the outbreak of cold-air events have been noted in high northern latitudes, as well as a quadrupole pattern in surface temperature over the Atlantic and western European sectors, but it is currently not understood why certain events descend to the surface while others do not. This study compares a new classification technique of weak vortex events, based on the distribution of potential vorticity, with that of an existing technique and demonstrates that the subdivision of such events into vortex displacements and vortex splits has important implications for tropospheric weather patterns on weekly to monthly time scales. Using reanalysis data it is found that vortex splitting events are correl...