The water mass variability and southward shift of the Southern Hemisphere mid-depth supergyre

The Southern Hemisphere subtropical supergyre at intermediate depths connects all three ocean basins and plays a significant role in responding and conveying the climate-change-related variations in the global ocean. On the basis of the Simple Ocean Data Assimilation (SODA) ocean reanalysis, the the...

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Bibliographic Details
Published in:Acta Oceanologica Sinica
Main Authors: Duan Yongliang, Hou Yijun, Liu Hongwei, Liu Yahao, Hou, YJ
Format: Article in Journal/Newspaper
Language:English
Published: 2013
Subjects:
Online Access:http://ir.qdio.ac.cn/handle/337002/16446
https://doi.org/10.1007/s13131-013-0380-7
Description
Summary:The Southern Hemisphere subtropical supergyre at intermediate depths connects all three ocean basins and plays a significant role in responding and conveying the climate-change-related variations in the global ocean. On the basis of the Simple Ocean Data Assimilation (SODA) ocean reanalysis, the thermohaline variability and southward shift of the mid-depth supergyre are demonstrated. The steric height of the subsurface relative to 1 500 m (400-1 500 m) from the SODA depicts exactly the flow patterns and variability of the oceanic supergyre. During 1958-2007 the water masses in the gyre interiors become cooler/fresher, with the significant exceptions of the Agulhas Current system and Agulhas leakage. The results also exhibit a pronounced strengthening of the inter-basin connection of the supergyre, and the strongest southward shift, by about 2.5A degrees over the whole period, occurs in the central-south Pacific, which is associated with the changes in the basin-scale wind forcing. The Southern Hemisphere subtropical supergyre at intermediate depths connects all three ocean basins and plays a significant role in responding and conveying the climate-change-related variations in the global ocean. On the basis of the Simple Ocean Data Assimilation (SODA) ocean reanalysis, the thermohaline variability and southward shift of the mid-depth supergyre are demonstrated. The steric height of the subsurface relative to 1 500 m (400-1 500 m) from the SODA depicts exactly the flow patterns and variability of the oceanic supergyre. During 1958-2007 the water masses in the gyre interiors become cooler/fresher, with the significant exceptions of the Agulhas Current system and Agulhas leakage. The results also exhibit a pronounced strengthening of the inter-basin connection of the supergyre, and the strongest southward shift, by about 2.5A degrees over the whole period, occurs in the central-south Pacific, which is associated with the changes in the basin-scale wind forcing.