The Role of Southern Ocean Transports on the Global Ocean Circulation
Abstract
The Southern Ocean (SO) is the focus of many physical, chemical, and biological analyses due to its global importance and highly variable climate. The SO is capable of transporting vast amounts of salt and heat, and the ability to regulate global climate. The variability of depth- and density-integrated volume transports in the SO is studied using Estimating the Circulation and Climate of the Ocean (ECCO) version 4 release 3 (1992-2015) ocean state estimate. Trends in net volume transport between the basins are statistically indistinguishable from zero, however, the middle and lower branches of the Meridional Overturning Circulation have trends of -0.289 Sv decade-1 and 0.248 Sv decade-1 in the Atlantic basin. The Indian and Pacific basins have decreasing trends in their lower overturning cells. These results indicate increased overturning circulation within the South Atlantic and decreased circulation within the Indian and Pacific, and have implications on the thermohaline-driven circulation. Using ECCO, we estimate a southward potential temperature (-176.2 ± 197.2°C Sv) and salinity (-1.71 ± 22.4 psu Sv) transport into the SO and indicate the net potential temperature transport across 30ºS is increasing (-0.125 ± 0.11°C Sv month-1). Our results imply the trend in potential temperature transports is largely driven by the surface waters of the Indian Ocean basin and could have major implications on thermohaline-driven circulation and the SO heat budget.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMOS31H1886F
- Keywords:
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- 4207 Arctic and Antarctic oceanography;
- OCEANOGRAPHY: GENERALDE: 4255 Numerical modeling;
- OCEANOGRAPHY: GENERALDE: 4260 Ocean data assimilation and reanalysis;
- OCEANOGRAPHY: GENERALDE: 4262 Ocean observing systems;
- OCEANOGRAPHY: GENERAL