The winter midlatitude-Arctic interaction: effects of North Atlantic SST and high-latitude blocking on Arctic sea ice and Eurasian cooling
The winter midlatitude-Arctic interaction: effects of North Atlantic SST and high-latitude blocking on Arctic sea ice and Eurasian cooling
复制标题
冬季中纬度-北极相互作用：北大西洋海温和高纬度阻塞对北极海冰和欧亚大陆降温的影响
DOI：
10.1007/s00382-018-4301-5
复制
发表时间：
2019-03-01
期刊：
影响因子：
4.6
通讯作者：
Simmonds, Ian
中科院分区：
文献类型：
--
作者：
Luo, Binhe;Wu, Lixin;Simmonds, Ian
在本文中，检查了欧亚循环模式（例如高纬度欧洲封锁（HEB）和URAL阻塞（UB）事件（UB）事件对Barents-Kara-kara海洋（BKS）和欧亚冷却的冬季海冰集中（SIC）的影响，以区分HEB和UB的北部北极大型振动（NAOO）（NAOO）（NAOO）（NAOO（NAOO）（NAOO）（NAOO）（+）。特定的重点是由于海面温度（SST）在海湾流延伸（GSE）区域的影响到欧亚阻塞的位置变化而产生的SIC变异性。发现SST在GSE的南部（北）显示出偶极子模式，而BKS中的高SST在BKS SIC下降中起着重要作用。与SST偶极子相关的北大西洋西风的加强倾向于促进与NAO（+）相关的长期UB和HEB事件，以进一步降低BKS SIC，而HEB和UB依赖于先前的BKS变暖，UB需要比HEB更强大的北大西洋风。在UB期间，GSE的温暖潮湿空气可以通过NAO（+） - UB继电器产生的北向运输来增强BKS，从而增强向下红外辐射（IR）。在HEB期间，下降IR很弱，因为水分主要运输到BK的西部，即使NAO（+） - HEB继电器仍然运行。因此，UB导致BKS海冰的下降比HEB以下更明显，尽管后者仍然显着导致SIC损失。还发现，UB期间发生的中东亚洲冷却与UB发作之前的BKS剧烈，广泛的SIC下降有关，而HEB期间的欧洲冷却与BKS西部的SIC下降有关。
In this paper, the effects of Eurasian circulation patterns such as high-latitude European blocking (HEB) and Ural blocking (UB) events on winter sea-ice concentration (SIC) in the Barents-Kara seas (BKS) and Eurasian cooling is examined to differentiate the different roles of HEB and UB in association with positive North Atlantic Oscillation (NAO(+)) events. A particular focus is on the SIC variability resulting from the effect of sea surface temperature (SST) near the Gulf Stream Extension (GSE) region through to the position change of Eurasian blocking. It is found that the SST shows a dipole pattern with a positive (negative) anomaly to the south (north) of the GSE, while the high SST in BKS plays a major role in the BKS SIC decline. The strengthening of North Atlantic westerly winds associated with the SST dipole tends to promote long-lived UB and HEB events associated with NAO(+) to further reduce the BKS SIC, while HEB and UB depend on the prior BKS warming and UB requires stronger North Atlantic westerly winds than HEB. During UB, warm moist air from the GSE can reach the BKS to enhance downward infrared radiation (IR) via increased northward transport produced by the NAO(+)-UB relay. The downward IR is weak during HEB as the moisture is transported mainly into the western part of BKS, even though the NAO(+)-HEB relay still operates. Thus, UB leads to more pronounced BKS sea-ice declines than under HEB, although the latter still significantly contributes to the SIC loss. It is also found that the central-eastern Asian cooling occurring during UB is related to an intense, widespread SIC decline in BKS prior to the UB onset, whereas the European cooling during HEB is linked to a small SIC decline in the western part of BKS.