Formation of bottom water and its variability in the northwestern part of the Sea of Japan
Formation of bottom water and its variability in the northwestern part of the Sea of Japan
复制标题
日本海西北部底层水的形成及其变化
DOI：
10.1002/2013jc009456
复制
发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Kiyoshi Tanaka
中科院分区：
文献类型：
--
作者：
上野健一;清水悟;佐藤香枝;南光一樹;Kiyoshi Tanaka
本文从动力学的角度考察了日本海西北部密集陆架水的下坡下降过程，重点考察了2001年冬季底水的形成过程。据推测，在1980年以前，彼得大帝湾的陆架水有时会下降到大陆坡下很远的地方，至少部分深度超过3000米（大陆坡脚）。然而，1980年以后，陆架水没有下降那么远；它要么只是适度下降，要么根本不下降。然而，在2001年冬季，密集的陆架水再次下降到超过3000米的深度，导致底部水的形成。超过3000米的下降是由于低温加上高盐度造成的，而20世纪后期的适度下降纯粹与陆架水的低温有关。据估计，在大陆斜坡上，陆架水与周围水的混合比例在深度下降时约为1:9，而在中度下降时约为1:5。底水的形成受年际大气变率的影响很大；因此，在2001年冬季，加强的西伯利亚高压（特别是在其北部）和阿留申低压的结合将非常冷的空气平流到东北亚，产生密集的陆架水并导致底部水的形成。
The downslope descent of dense shelf water in the northwestern part of the Sea of Japan is investigated from a dynamical point of view, paying attention to the formation of bottom water in the winter of 2001. It is supposed that before 1980, the shelf water in Peter the Great Bay sometimes descended far down the continental slope, at least partly reaching depths in excess of 3000 m (the foot of the continental slope). After 1980, however, the shelf water did not descend as far; it either descended only moderately or not at all. In Winter 2001, however, the dense shelf water again descended to depths greater than 3000 m, resulting in the formation of bottom water. Descents of more than 3000 m are due to low temperatures coupled with high salinities, whereas the moderate descents of the late 20th century were purely related to the low temperature of the shelf water. It is estimated that over the continental slope, the shelf water becomes mixed with the ambient water in a ratio of about 1:9 for deep descents, whereas the ratio is about 1:5 for moderate descents. The formation of bottom water is greatly influenced by interannual atmospheric variability; thus in Winter 2001 a combination of the strengthened Siberian High (especially in its northern part) and the Aleutian Low advected very cold air into northeast Asia, producing dense shelf water and resulting in the formation of bottom water.