Geophysical Institute, University of Bergen and Bjerknes Centre for Climate Research, Bergen, Norway.
Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA.
Nat Commun. 2020 Oct 23;11(1):5390. doi: 10.1038/s41467-020-19049-5.
Dense water from the Nordic Seas passes through the Faroe Bank Channel and supplies the lower limb of the Atlantic Meridional Overturning Circulation, a critical component of the climate system. Yet, the upstream pathways of this water are not fully known. Here we present evidence of a previously unrecognised deep current following the slope from Iceland toward the Faroe Bank Channel using high-resolution, synoptic shipboard observations and long-term measurements north of the Faroe Islands. The bulk of the volume transport of the current, named the Iceland-Faroe Slope Jet (IFSJ), is relatively uniform in hydrographic properties, very similar to the North Icelandic Jet flowing westward along the slope north of Iceland toward Denmark Strait. This suggests a common source for the two major overflows across the Greenland-Scotland Ridge. The IFSJ can account for approximately half of the total overflow transport through the Faroe Bank Channel, thus constituting a significant component of the overturning circulation in the Nordic Seas.
来自北欧海域的高密度水通过法罗海槛,为北大西洋经向翻转环流的下游提供水源,这是气候系统的一个关键组成部分。然而,这条水流的上游路径还不完全清楚。在这里,我们利用高分辨率的天气船观测和法罗群岛北部的长期测量结果,提供了一条以前未被识别的沿着冰岛向法罗海槛倾斜的深水流的证据。这条名为冰岛-法罗海槛斜坡急流(IFSJ)的主流的大部分体积输送相对均匀,其水文学性质与沿冰岛北部向丹麦海峡向西流动的北冰岛急流非常相似。这表明这两个主要的越岭溢流有共同的源区。IFSJ 可以占到通过法罗海槛总溢流输送量的大约一半,因此构成了北欧海域经向翻转环流的一个重要组成部分。