Transient overturning compensation between Atlantic and Indo-Pacific basins
Climate models consistently project (i) a decline in the formation of North Atlantic Deep Water (NADW) and (ii) a strengthening of the Southern Hemisphere westerly winds in response to anthropogenic greenhouse gas forcing. These two processes suggest potentially conflicting tendencies of the Atlanti...
Main Authors: | , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
American Meteorological Society
2020
|
Subjects: | |
Online Access: | https://authors.library.caltech.edu/104402/ https://authors.library.caltech.edu/104402/3/jpod200060.pdf https://resolver.caltech.edu/CaltechAUTHORS:20200716-101103298 |
id |
ftcaltechauth:oai:authors.library.caltech.edu:104402 |
---|---|
record_format |
openpolar |
spelling |
ftcaltechauth:oai:authors.library.caltech.edu:104402 2023-05-15T17:13:52+02:00 Transient overturning compensation between Atlantic and Indo-Pacific basins Sun, Shantong Thompson, Andrew F. 2020-08 application/pdf https://authors.library.caltech.edu/104402/ https://authors.library.caltech.edu/104402/3/jpod200060.pdf https://resolver.caltech.edu/CaltechAUTHORS:20200716-101103298 unknown American Meteorological Society https://authors.library.caltech.edu/104402/3/jpod200060.pdf Sun, Shantong and Thompson, Andrew F. (2020) Transient overturning compensation between Atlantic and Indo-Pacific basins. Journal of Physical Oceanography, 50 (8). pp. 2151-2172. ISSN 0022-3670. https://resolver.caltech.edu/CaltechAUTHORS:20200716-101103298 <https://resolver.caltech.edu/CaltechAUTHORS:20200716-101103298> Article PeerReviewed 2020 ftcaltechauth 2020-11-05T18:04:19Z Climate models consistently project (i) a decline in the formation of North Atlantic Deep Water (NADW) and (ii) a strengthening of the Southern Hemisphere westerly winds in response to anthropogenic greenhouse gas forcing. These two processes suggest potentially conflicting tendencies of the Atlantic meridional overturning circulation (AMOC): a weakening AMOC due to changes in the North Atlantic but a strengthening AMOC due to changes in the Southern Ocean. Here we focus on the transient evolution of the global ocean overturning circulation in response to a perturbation to the NADW formation rate. We propose that the adjustment of the Indo-Pacific overturning circulation is a critical component in mediating AMOC changes. Using a hierarchy of ocean and climate models, we show that the Indo-Pacific overturning circulation provides the first response to AMOC changes through wave processes, whereas the Southern Ocean overturning circulation responds on longer (centennial to millennial) time scales that are determined by eddy diffusion processes. Changes in the Indo-Pacific overturning circulation compensate AMOC changes, which allows the Southern Ocean overturning circulation to evolve independently of the AMOC, at least over time scales up to many decades. In a warming climate, the Indo-Pacific develops an overturning circulation anomaly associated with the weakening AMOC that is characterized by a northward transport close to the surface and a southward transport in the deep ocean, which could effectively redistribute heat between the basins. Our results highlight the importance of interbasin exchange in the response of the global ocean overturning circulation to a changing climate. Article in Journal/Newspaper NADW North Atlantic Deep Water North Atlantic Southern Ocean Caltech Authors (California Institute of Technology) Pacific Southern Ocean |
institution |
Open Polar |
collection |
Caltech Authors (California Institute of Technology) |
op_collection_id |
ftcaltechauth |
language |
unknown |
description |
Climate models consistently project (i) a decline in the formation of North Atlantic Deep Water (NADW) and (ii) a strengthening of the Southern Hemisphere westerly winds in response to anthropogenic greenhouse gas forcing. These two processes suggest potentially conflicting tendencies of the Atlantic meridional overturning circulation (AMOC): a weakening AMOC due to changes in the North Atlantic but a strengthening AMOC due to changes in the Southern Ocean. Here we focus on the transient evolution of the global ocean overturning circulation in response to a perturbation to the NADW formation rate. We propose that the adjustment of the Indo-Pacific overturning circulation is a critical component in mediating AMOC changes. Using a hierarchy of ocean and climate models, we show that the Indo-Pacific overturning circulation provides the first response to AMOC changes through wave processes, whereas the Southern Ocean overturning circulation responds on longer (centennial to millennial) time scales that are determined by eddy diffusion processes. Changes in the Indo-Pacific overturning circulation compensate AMOC changes, which allows the Southern Ocean overturning circulation to evolve independently of the AMOC, at least over time scales up to many decades. In a warming climate, the Indo-Pacific develops an overturning circulation anomaly associated with the weakening AMOC that is characterized by a northward transport close to the surface and a southward transport in the deep ocean, which could effectively redistribute heat between the basins. Our results highlight the importance of interbasin exchange in the response of the global ocean overturning circulation to a changing climate. |
format |
Article in Journal/Newspaper |
author |
Sun, Shantong Thompson, Andrew F. |
spellingShingle |
Sun, Shantong Thompson, Andrew F. Transient overturning compensation between Atlantic and Indo-Pacific basins |
author_facet |
Sun, Shantong Thompson, Andrew F. |
author_sort |
Sun, Shantong |
title |
Transient overturning compensation between Atlantic and Indo-Pacific basins |
title_short |
Transient overturning compensation between Atlantic and Indo-Pacific basins |
title_full |
Transient overturning compensation between Atlantic and Indo-Pacific basins |
title_fullStr |
Transient overturning compensation between Atlantic and Indo-Pacific basins |
title_full_unstemmed |
Transient overturning compensation between Atlantic and Indo-Pacific basins |
title_sort |
transient overturning compensation between atlantic and indo-pacific basins |
publisher |
American Meteorological Society |
publishDate |
2020 |
url |
https://authors.library.caltech.edu/104402/ https://authors.library.caltech.edu/104402/3/jpod200060.pdf https://resolver.caltech.edu/CaltechAUTHORS:20200716-101103298 |
geographic |
Pacific Southern Ocean |
geographic_facet |
Pacific Southern Ocean |
genre |
NADW North Atlantic Deep Water North Atlantic Southern Ocean |
genre_facet |
NADW North Atlantic Deep Water North Atlantic Southern Ocean |
op_relation |
https://authors.library.caltech.edu/104402/3/jpod200060.pdf Sun, Shantong and Thompson, Andrew F. (2020) Transient overturning compensation between Atlantic and Indo-Pacific basins. Journal of Physical Oceanography, 50 (8). pp. 2151-2172. ISSN 0022-3670. https://resolver.caltech.edu/CaltechAUTHORS:20200716-101103298 <https://resolver.caltech.edu/CaltechAUTHORS:20200716-101103298> |
_version_ |
1766071053193314304 |