Large Multidecadal Salinity Trends near the Pacific-Antarctic Continental Margin
Large Multidecadal Salinity Trends near the Pacific-Antarctic Continental Margin
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DOI：
10.1175/2010jcli3284.1
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发表时间：
2010-09-01
影响因子：
4.9
通讯作者：
Giulivi, Claudia F.
中科院分区：
文献类型：
--
作者：
Jacobs, Stanley S.;Giulivi, Claudia F.
对西南太平洋部分南极大陆架上和附近的海洋温度和盐度测量值进行了评价，以寻找时间变化的证据。从1958年到2008年，罗斯海西南部的陆架水的盐度下降了0.03decade（-1），而其温度则与盐度对海面冰点的影响成比例地上升。自20世纪70年代末以来，到达罗斯冰架中部的修改后的深水入侵物以类似的速度变淡，并冷却了0.5摄氏度。向西海岸和斜坡前缘流的盐度下降了0.08decade（-1），这与阿蒙森海上游大陆冰融化增加一致。这些近地表沃茨在冬季海冰形成和混合的斜坡前翻转足以占5十年的陆架水盐度变化。一个强的相关性之间的清新和南部的环形模式指数的变化表明与大规模的大气环流的联系。在大陆坡以北东经140度至180度之间的底层和较低的深沃茨，盐度下降了约0.01十年（-1）。伴随的深海温度变化很小，变异性很大，但密度沿着盐度下降。水柱分层的持续增加将改变该区域产生的底层和深层沃茨的模式和形成速率以及性质。
Ocean temperature and salinity measurements on and near the Antarctic continental shelf in the southwest Pacific sector are evaluated for evidence of temporal change. Shelf water in the southwest Ross Sea has declined in salinity by 0.03 decade(-1) from 1958 to 2008, while its temperatures have increased in proportion to the influence of salinity on the sea surface freezing point. Modified deep-water intrusions that reach the central Ross Ice Shelf have freshened at a similar rate and cooled by similar to 0.5 degrees C since the late 1970s. Salinity has decreased by 0.08 decade(-1) in the westward coastal and slope front currents, consistent with increased melting of continental ice upstream in the Amundsen Sea. Overturning of those near-surface waters during winter sea ice formation and mixing across the slope front is sufficient to account for the 5-decade shelf water salinity change. A strong correlation between the freshening and change in the southern annular mode index suggests a link with the large-scale atmospheric circulation. Salinity has decreased by similar to 0.01 decade(-1) in bottom and lower deep waters north of the continental slope between 140E degrees and 180 degrees. Accompanying abyssal temperature changes are minor and variability is high, but density has declined along with salinity. Continued increases in water column stratification will modify the mode and formation rate as well as the properties of bottom and deep waters produced in this region.