Response of thermohaline circulation to freshwater forcing under present-day and LGM conditions
Responses of the thermohaline circulation (THC) to freshwater forcing (hosing) in the subpolar North Atlantic Ocean under present-day and the last glacial maximum (LGM) conditions are investigated using the National Center for Atmospheric Research Community Climate System Model versions 2 and 3. Thr...
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ftncar:oai:drupal-site.org:articles_17500 2023-09-05T13:17:18+02:00 Response of thermohaline circulation to freshwater forcing under present-day and LGM conditions Hu, Aixue (author) Otto-Bliesner, Bette (author) Meehl, Gerald (author) Han, Weiqing (author) Morrill, Carrie (author) Brady, Esther (author) Briegleb, Bruce (author) 2008-05-01 application/pdf http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-002-212 https://doi.org/10.1175/2007JCLI1985.1 en eng American Meteorological Society Journal of Climate http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-002-212 doi:10.1175/2007JCLI1985.1 ark:/85065/d77h1kwj Copyright 2008 American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be "fair use" under Section 107 or that satisfies the conditions specified in Section 108 of the U.S. Copyright Law (17 USC, as revised by P.L. 94-553) does not require the Society's permission. Republication, systematic reproduction, posting in electronic form on servers, or other uses of this material, except as exempted by the above statements, requires written permission or license from the AMS. Additional details are provided in the AMS Copyright Policies, available from the AMS at 617-227-2425 or amspubs@ametsoc.org. Permission to place a copy of this work on this server has been provided by the AMS. The AMS does not guarantee that the copy provided here is an accurate copy of the published work. thermohaline circulation freshwater forcings Text article 2008 ftncar https://doi.org/10.1175/2007JCLI1985.1 2023-08-14T18:44:44Z Responses of the thermohaline circulation (THC) to freshwater forcing (hosing) in the subpolar North Atlantic Ocean under present-day and the last glacial maximum (LGM) conditions are investigated using the National Center for Atmospheric Research Community Climate System Model versions 2 and 3. Three sets of simulations are analyzed, with each set including a control run and a freshwater hosing run. The first two sets are under present-day conditions with an open and closed Bering Strait. The third one is under LGM conditions, which has a closed Bering Strait. Results show that the THC nearly collapses in all three hosing runs when the freshwater forcing is turned on. The full recovery of the THC, however, is at least a century earlier in the open Bering Strait run than the closed Bering Strait and LGM runs. This is because the excessive freshwater is diverged almost equally toward north and south from the subpolar North Atlantic when the Bering Strait is open. A significant portion of the freshwater flowing northward into the Arctic exits into the North Pacific via a reversed Bering Strait Throughflow, which accelerates the THC recovery. When the Bering Strait is closed, this Arctic to Pacific transport is absent and freshwater can only be removed through the southern end of the North Atlantic. Together with the surface freshwater excess due to precipitation, evaporation, river runoff, and melting ice in the closed Bering Strait experiments after the hosing, the removal of the excessive freshwater takes longer, and this slows the recovery of the THC. Although the background conditions are quite different between the present-day closed Bering Strait run and the LGM run, the THC responds to the freshwater forcing added in the North Atlantic in a very similar manner. National Aeronautics and Space Administration (NASA): 1283568 National Science Foundation (NSF): OCE- 0452917 DE-FC03-97ER62402 Article in Journal/Newspaper Arctic Bering Strait North Atlantic OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) Arctic Bering Strait Pacific Journal of Climate 21 10 2239 2258 |
institution |
Open Polar |
collection |
OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) |
op_collection_id |
ftncar |
language |
English |
topic |
thermohaline circulation freshwater forcings |
spellingShingle |
thermohaline circulation freshwater forcings Response of thermohaline circulation to freshwater forcing under present-day and LGM conditions |
topic_facet |
thermohaline circulation freshwater forcings |
description |
Responses of the thermohaline circulation (THC) to freshwater forcing (hosing) in the subpolar North Atlantic Ocean under present-day and the last glacial maximum (LGM) conditions are investigated using the National Center for Atmospheric Research Community Climate System Model versions 2 and 3. Three sets of simulations are analyzed, with each set including a control run and a freshwater hosing run. The first two sets are under present-day conditions with an open and closed Bering Strait. The third one is under LGM conditions, which has a closed Bering Strait. Results show that the THC nearly collapses in all three hosing runs when the freshwater forcing is turned on. The full recovery of the THC, however, is at least a century earlier in the open Bering Strait run than the closed Bering Strait and LGM runs. This is because the excessive freshwater is diverged almost equally toward north and south from the subpolar North Atlantic when the Bering Strait is open. A significant portion of the freshwater flowing northward into the Arctic exits into the North Pacific via a reversed Bering Strait Throughflow, which accelerates the THC recovery. When the Bering Strait is closed, this Arctic to Pacific transport is absent and freshwater can only be removed through the southern end of the North Atlantic. Together with the surface freshwater excess due to precipitation, evaporation, river runoff, and melting ice in the closed Bering Strait experiments after the hosing, the removal of the excessive freshwater takes longer, and this slows the recovery of the THC. Although the background conditions are quite different between the present-day closed Bering Strait run and the LGM run, the THC responds to the freshwater forcing added in the North Atlantic in a very similar manner. National Aeronautics and Space Administration (NASA): 1283568 National Science Foundation (NSF): OCE- 0452917 DE-FC03-97ER62402 |
author2 |
Hu, Aixue (author) Otto-Bliesner, Bette (author) Meehl, Gerald (author) Han, Weiqing (author) Morrill, Carrie (author) Brady, Esther (author) Briegleb, Bruce (author) |
format |
Article in Journal/Newspaper |
title |
Response of thermohaline circulation to freshwater forcing under present-day and LGM conditions |
title_short |
Response of thermohaline circulation to freshwater forcing under present-day and LGM conditions |
title_full |
Response of thermohaline circulation to freshwater forcing under present-day and LGM conditions |
title_fullStr |
Response of thermohaline circulation to freshwater forcing under present-day and LGM conditions |
title_full_unstemmed |
Response of thermohaline circulation to freshwater forcing under present-day and LGM conditions |
title_sort |
response of thermohaline circulation to freshwater forcing under present-day and lgm conditions |
publisher |
American Meteorological Society |
publishDate |
2008 |
url |
http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-002-212 https://doi.org/10.1175/2007JCLI1985.1 |
geographic |
Arctic Bering Strait Pacific |
geographic_facet |
Arctic Bering Strait Pacific |
genre |
Arctic Bering Strait North Atlantic |
genre_facet |
Arctic Bering Strait North Atlantic |
op_relation |
Journal of Climate http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-002-212 doi:10.1175/2007JCLI1985.1 ark:/85065/d77h1kwj |
op_rights |
Copyright 2008 American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be "fair use" under Section 107 or that satisfies the conditions specified in Section 108 of the U.S. Copyright Law (17 USC, as revised by P.L. 94-553) does not require the Society's permission. Republication, systematic reproduction, posting in electronic form on servers, or other uses of this material, except as exempted by the above statements, requires written permission or license from the AMS. Additional details are provided in the AMS Copyright Policies, available from the AMS at 617-227-2425 or amspubs@ametsoc.org. Permission to place a copy of this work on this server has been provided by the AMS. The AMS does not guarantee that the copy provided here is an accurate copy of the published work. |
op_doi |
https://doi.org/10.1175/2007JCLI1985.1 |
container_title |
Journal of Climate |
container_volume |
21 |
container_issue |
10 |
container_start_page |
2239 |
op_container_end_page |
2258 |
_version_ |
1776198528088932352 |