Interannual Variability of the Outflow of Weddell Sea Bottom Water
Interannual Variability of the Outflow of Weddell Sea Bottom Water
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DOI：
10.1029/2020gl087014
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发表时间：
2020-02-28
影响因子：
5.2
通讯作者：
Abrahamsen, E. Povl
中科院分区：
文献类型：
--
作者：
Gordon, Arnold L.;Huber, Bruce A.;Abrahamsen, E. Povl
1999年至2019年的威德尔海底水（WSBW）出口显示出明显的季节和年际变化。从2014年到2017年，记录的盐度显著下降，2016年初达到最低盐度34.615。降低的盐度来自V形槽形成的双重前沿着的威德尔环流的西部边界，这是充满了混合的地表水和修改威德尔深水的陆棚休息。我们估计，当V形顶点达到大于类似于700米的深度时，温压效应促进其下降到WSBW。我们认为，这发生在2014年至2017年威德尔环流上异常强烈的气旋风应力旋度期间，这增加了环流及其西部边界流的强度，加深了V形槽。随着2018年风应力的放松，WSBW盐度增加到2014年之前的值。
The Weddell Sea Bottom Water (WSBW) export from 1999 to 2019 displays distinct seasonal and interannual variability. From 2014 into 2017 a marked salinity decrease was recorded, with the lowest salinity, 34.615, attained in early 2016. The reduced salinity is derived from the V-shaped trough formed by a double front along the shelf break of the Weddell Gyre's western boundary, which is filled with a blend of surface water and modified Weddell Deep Water. We estimate that when the V-shaped apex attains a depth of greater than similar to 700 m, the thermobaric effect promotes its descent into the WSBW. We propose that this occurred during anomalously strong cyclonic wind stress curl over the Weddell Gyre from 2014 into 2017, which increased the intensity of the gyre and its western boundary current, deepening the V-shape trough. The WSBW salinity increased to its prior to 2014 values as the wind stress relaxed in 2018.