Exploring AMOC Regime Change over the Past Four Decades through Ocean Reanalyses
We examine North Atlantic climate variability using an ensemble of ocean reanalysis datasets to study the Atlantic Meridional Overturning Circulation (AMOC) from 1979 to 2018. The dataset intercomparison shows good agreement for the latest period (1995–2018) for AMOC dynamics, characterized by a wea...
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ftmdpi:oai:mdpi.com:/2225-1154/10/4/59/ 2023-08-20T04:07:49+02:00 Exploring AMOC Regime Change over the Past Four Decades through Ocean Reanalyses Vincenzo de Toma Vincenzo Artale Chunxue Yang agris 2022-04-08 application/pdf https://doi.org/10.3390/cli10040059 EN eng Multidisciplinary Digital Publishing Institute https://dx.doi.org/10.3390/cli10040059 https://creativecommons.org/licenses/by/4.0/ Climate; Volume 10; Issue 4; Pages: 59 North Atlantic ocean heat content ocean reanalyses Atlantic Meridional Overturning Circulation sea surface temperature Gulf Stream Labrador Sea deep water formation Text 2022 ftmdpi https://doi.org/10.3390/cli10040059 2023-08-01T04:42:13Z We examine North Atlantic climate variability using an ensemble of ocean reanalysis datasets to study the Atlantic Meridional Overturning Circulation (AMOC) from 1979 to 2018. The dataset intercomparison shows good agreement for the latest period (1995–2018) for AMOC dynamics, characterized by a weaker overturning circulation after 1995 and a more intense one during 1979–1995, with varying intensity across the various datasets. The correlation between leading empirical orthogonal functions suggests that the AMOC weakening has connections with cooler (warmer) sea surface temperature (SST) and lower (higher) ocean heat content in the subpolar (subtropical) gyre in the North Atlantic. Barotropic stream function and Gulf Stream index reveal a shrinking subpolar gyre and an expanding subtropical gyre during the strong-AMOC period and vice versa, consistently with Labrador Sea deep convection reduction. We also observed an east–west salt redistribution between the two periods. Additional analyses show that the AMOC variability is related to the North Atlantic Oscillation phase change around 1995. One of the datasets included in the comparison shows an overestimation of AMOC variability, notwithstanding the model SST bias reduction via ERA-Interim flux adjustments: further studies with a set of numerical experiments will help explain this behavior. Text Labrador Sea North Atlantic North Atlantic oscillation MDPI Open Access Publishing Climate 10 4 59 |
institution |
Open Polar |
collection |
MDPI Open Access Publishing |
op_collection_id |
ftmdpi |
language |
English |
topic |
North Atlantic ocean heat content ocean reanalyses Atlantic Meridional Overturning Circulation sea surface temperature Gulf Stream Labrador Sea deep water formation |
spellingShingle |
North Atlantic ocean heat content ocean reanalyses Atlantic Meridional Overturning Circulation sea surface temperature Gulf Stream Labrador Sea deep water formation Vincenzo de Toma Vincenzo Artale Chunxue Yang Exploring AMOC Regime Change over the Past Four Decades through Ocean Reanalyses |
topic_facet |
North Atlantic ocean heat content ocean reanalyses Atlantic Meridional Overturning Circulation sea surface temperature Gulf Stream Labrador Sea deep water formation |
description |
We examine North Atlantic climate variability using an ensemble of ocean reanalysis datasets to study the Atlantic Meridional Overturning Circulation (AMOC) from 1979 to 2018. The dataset intercomparison shows good agreement for the latest period (1995–2018) for AMOC dynamics, characterized by a weaker overturning circulation after 1995 and a more intense one during 1979–1995, with varying intensity across the various datasets. The correlation between leading empirical orthogonal functions suggests that the AMOC weakening has connections with cooler (warmer) sea surface temperature (SST) and lower (higher) ocean heat content in the subpolar (subtropical) gyre in the North Atlantic. Barotropic stream function and Gulf Stream index reveal a shrinking subpolar gyre and an expanding subtropical gyre during the strong-AMOC period and vice versa, consistently with Labrador Sea deep convection reduction. We also observed an east–west salt redistribution between the two periods. Additional analyses show that the AMOC variability is related to the North Atlantic Oscillation phase change around 1995. One of the datasets included in the comparison shows an overestimation of AMOC variability, notwithstanding the model SST bias reduction via ERA-Interim flux adjustments: further studies with a set of numerical experiments will help explain this behavior. |
format |
Text |
author |
Vincenzo de Toma Vincenzo Artale Chunxue Yang |
author_facet |
Vincenzo de Toma Vincenzo Artale Chunxue Yang |
author_sort |
Vincenzo de Toma |
title |
Exploring AMOC Regime Change over the Past Four Decades through Ocean Reanalyses |
title_short |
Exploring AMOC Regime Change over the Past Four Decades through Ocean Reanalyses |
title_full |
Exploring AMOC Regime Change over the Past Four Decades through Ocean Reanalyses |
title_fullStr |
Exploring AMOC Regime Change over the Past Four Decades through Ocean Reanalyses |
title_full_unstemmed |
Exploring AMOC Regime Change over the Past Four Decades through Ocean Reanalyses |
title_sort |
exploring amoc regime change over the past four decades through ocean reanalyses |
publisher |
Multidisciplinary Digital Publishing Institute |
publishDate |
2022 |
url |
https://doi.org/10.3390/cli10040059 |
op_coverage |
agris |
genre |
Labrador Sea North Atlantic North Atlantic oscillation |
genre_facet |
Labrador Sea North Atlantic North Atlantic oscillation |
op_source |
Climate; Volume 10; Issue 4; Pages: 59 |
op_relation |
https://dx.doi.org/10.3390/cli10040059 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3390/cli10040059 |
container_title |
Climate |
container_volume |
10 |
container_issue |
4 |
container_start_page |
59 |
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1774719723782537216 |