Meridional Gulf Stream Shifts Can Influence Wintertime Variability in the North Atlantic Storm Track and Greenland Blocking
Meridional Gulf Stream Shifts Can Influence Wintertime Variability in the North Atlantic Storm Track and Greenland Blocking
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DOI：
10.1029/2018gl081087
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发表时间：
2019-02
影响因子：
5.2
通讯作者：
T. Joyce;Young‐Oh Kwon;H. Seo;C. Ummenhofer
中科院分区：
文献类型：
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作者：
T. Joyce;Young‐Oh Kwon;H. Seo;C. Ummenhofer
离开美国东海岸后，向北流动的墨西哥湾流（GS）成为纬向急流，并将其强气流和海表温度梯度的锋面特征带进北大西洋中纬度地区。它离开海岸的分离位置也是冬季天气风暴路径在北美继续发展并穿越海洋的锚点。我们研究了分离的GS路径在年际和年代际时间尺度上的经向变化，作为1979 - 2012年对流层中风暴路径和阻塞变化的类似变化的代理。我们发现，GS路径偏北（偏南）期与天气风暴路径向拉布拉多海东北方向漂移增加（抑制）和格陵兰阻塞减少（增强）有关。在这两种情况下，地球磁场的移动都比对流层中部的移动早几个月。
After leaving the U.S. East Coast, the northward flowing Gulf Stream (GS) becomes a zonal jet and carries along its frontal characteristics of strong flow and sea surface temperature gradients into the North Atlantic at midlatitudes. The separation location where it leaves the coast is also an anchor point for the wintertime synoptic storm track across North America to continue to develop and head across the ocean. We examine the meridional variability of the separated GS path on interannual to decadal time scales as an agent for similar changes in the storm track and blocking variability at midtroposphere from 1979 to 2012. We find that periods of northerly (southerly) GS path are associated with increased (suppressed) excursions of the synoptic storm track to the northeast over the Labrador Sea and reduced (enhanced) Greenland blocking. In both instances, GS shifts lead those in the midtroposphere by a few months.