The PRIME eddy
The PRIME eddy
复制标题
DOI：
10.1357/002224098321822375
复制
发表时间：
1998-03-01
影响因子：
0.5
通讯作者：
Heywood, KJ
中科院分区：
文献类型：
--
作者：
Martin, AP;Wade, IP;Heywood, KJ
在冰岛海盆59.1 N 20 W处有一个具有强烈反气旋环流和冷表面温度异常（-1 ℃）的温跃层内透镜。该透镜厚1000米，宽120公里，中心在700米处的27.45西格玛（0）等密度线上。它的影响，通过扭曲的密度表面，是整个2800米水柱感觉。在表面，这导致涡流内的混合层较浅，这将对当地的生态系统产生影响。在700米深度和半径为40公里的涡流环流的方位角速度类似于40厘米秒（-1）。这一行有很强的正压分量。潜在温度（7.8 ℃）和盐度（35.18）在整个岩芯中是均匀的-尽管有证据表明有三层组成-这与高氧含量（6.4 ml（-1））和低Brunt Vaisala频率（类似于2 x 10（-4）s（-1））一起表明涡流是由深冬混合产生的模态水形成的。海洋表面温度（SST）卫星图像显示了涡旋的冷表面特征，揭示了该区域也有两个类似的特征。在卫星覆盖的五个月里，没有一个漩涡有明显的移动，三个漩涡形成了一条线，与哈顿银行平行。这表明，它们可能是由环绕银行南端的北大西洋海流（NAC）产生的。如果普遍的话，估计表明，这些特征可能会从东部模式沃茨向西输送大量的盐和热量，穿过NAC的最东端。
An intrathermocline lens with strong anticyclonic circulation and cold surface temperature anomaly (-1 degrees C) is reported in the Iceland Basin at 59.1N 20W. The lens is 1000 m thick, 120 km wide and centered on the 27.45 sigma(0) isopycnal at 700 m. Its influence, through distortion of density surfaces, is felt throughout the 2800 m water column. At the surface this leads to a shallower mixed layer within the eddy which will have an impact on the local planktonic ecology. At a depth of 700 m and a radius of 40 km the eddy circulation has an azimuthal velocity of similar to 40 cm s(-1). This Row has a strong barotropic component. Potential temperature (7.8 degrees C) and salinity (35.18) are homogeneous throughout the core-though there is evidence for a three-layer composition-which, together with a high oxygen content (6.4 mi l(-1)) and low Brunt Vaisala frequency (similar to 2 x 10(-4) s(-1)), suggest that the eddy is formed from mode water created by deep winter mixing. Sea-Surface Temperature (SST) satellite images, displaying the cold surface signature of the eddy, reveal two similar features also in the region. None of the eddies moves appreciably in the five months of satellite coverage, the three forming a line northwest of, and parallel to, the Hatton Bank. This suggests that they may be produced by the North Atlantic Current (NAC) rounding the southern end of the bank. If common, estimates suggest that such features may be transporting significant amounts of salt and heat, from eastern mode waters, westward across the easternmost front of the NAC.