Variability of the ocean heat content during the last millennium – an assessment with the ECHO-g Model
Studies addressing climate variability during the last millennium generally focus on variables with a direct influence on climate variability, like the fast thermal response to varying radiative forcing, or the large-scale changes in atmospheric dynamics (e.g. North Atlantic Oscillation). The ocean...
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Online Access: | http://hdl.handle.net/10261/76905 https://doi.org/10.5194/cp-9-547-2013 |
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ftcsic:oai:digital.csic.es:10261/76905 2024-02-11T10:06:14+01:00 Variability of the ocean heat content during the last millennium – an assessment with the ECHO-g Model Ortega, P. Montoya, Marisa González-Rouco, J. F. Beltrami, H. Swingedouw, Didier 2013-03-04 http://hdl.handle.net/10261/76905 https://doi.org/10.5194/cp-9-547-2013 en eng European Geosciences Union Copernicus Publications Publisher’s version http://dx.doi.org/10.5194/cp-9-547-2013 Ortega, P., Montoya, M., González-Rouco, F., Beltrami, H., & Swingedouw, D. (2013). Variability of the ocean heat content during the last millennium – an assessment with the ECHO-g Model. Climate of the Past, 9(2), 547–565. doi:10.5194/cp-9-547-2013 http://hdl.handle.net/10261/76905 doi:10.5194/cp-9-547-2013 open Climate Clima North-Atlantic oscillation General circulation model Coupled climate model Sea level Thermohaline circulation artículo http://purl.org/coar/resource_type/c_6501 2013 ftcsic https://doi.org/10.5194/cp-9-547-2013 2024-01-16T09:49:45Z Studies addressing climate variability during the last millennium generally focus on variables with a direct influence on climate variability, like the fast thermal response to varying radiative forcing, or the large-scale changes in atmospheric dynamics (e.g. North Atlantic Oscillation). The ocean responds to these variations by slowly integrating in depth the upper heat flux changes, thus producing a delayed influence on ocean heat content (OHC) that can later impact low frequency SST (sea surface temperature) variability through reemergence processes. In this study, both the externally and internally driven variations of the OHC during the last millennium are investigated using a set of fully coupled simulations with the ECHO-G (coupled climate model ECHAMA4 and ocean model HOPE-G) atmosphere–ocean general circulation model (AOGCM). When compared to observations for the last 55 yr, the model tends to overestimate the global trends and underestimate the decadal OHC variability. Extending the analysis back to the last one thousand years, the main impact of the radiative forcing is an OHC increase at high latitudes, explained to some extent by a reduction in cloud cover and the subsequent increase of short-wave radiation at the surface. This OHC response is dominated by the effect of volcanism in the preindustrial era, and by the fast increase of GHGs during the last 150 yr. Likewise, salient impacts from internal climate variability are observed at regional scales. For instance, upper temperature in the equatorial Pacific is controlled by ENSO (El Niño Southern Oscillation) variability from interannual to multidecadal timescales. Also, both the Pacific Decadal Oscillation (PDO) and the Atlantic Multidecadal Oscillation (AMO) modulate intermittently the interdecadal OHC variability in the North Pacific and Mid Atlantic, respectively. The NAO, through its influence on North Atlantic surface heat fluxes and convection, also plays an important role on the OHC at multiple timescales, leading first to a cooling in ... Article in Journal/Newspaper North Atlantic North Atlantic oscillation Digital.CSIC (Spanish National Research Council) Pacific Climate of the Past 9 2 547 565 |
institution |
Open Polar |
collection |
Digital.CSIC (Spanish National Research Council) |
op_collection_id |
ftcsic |
language |
English |
topic |
Climate Clima North-Atlantic oscillation General circulation model Coupled climate model Sea level Thermohaline circulation |
spellingShingle |
Climate Clima North-Atlantic oscillation General circulation model Coupled climate model Sea level Thermohaline circulation Ortega, P. Montoya, Marisa González-Rouco, J. F. Beltrami, H. Swingedouw, Didier Variability of the ocean heat content during the last millennium – an assessment with the ECHO-g Model |
topic_facet |
Climate Clima North-Atlantic oscillation General circulation model Coupled climate model Sea level Thermohaline circulation |
description |
Studies addressing climate variability during the last millennium generally focus on variables with a direct influence on climate variability, like the fast thermal response to varying radiative forcing, or the large-scale changes in atmospheric dynamics (e.g. North Atlantic Oscillation). The ocean responds to these variations by slowly integrating in depth the upper heat flux changes, thus producing a delayed influence on ocean heat content (OHC) that can later impact low frequency SST (sea surface temperature) variability through reemergence processes. In this study, both the externally and internally driven variations of the OHC during the last millennium are investigated using a set of fully coupled simulations with the ECHO-G (coupled climate model ECHAMA4 and ocean model HOPE-G) atmosphere–ocean general circulation model (AOGCM). When compared to observations for the last 55 yr, the model tends to overestimate the global trends and underestimate the decadal OHC variability. Extending the analysis back to the last one thousand years, the main impact of the radiative forcing is an OHC increase at high latitudes, explained to some extent by a reduction in cloud cover and the subsequent increase of short-wave radiation at the surface. This OHC response is dominated by the effect of volcanism in the preindustrial era, and by the fast increase of GHGs during the last 150 yr. Likewise, salient impacts from internal climate variability are observed at regional scales. For instance, upper temperature in the equatorial Pacific is controlled by ENSO (El Niño Southern Oscillation) variability from interannual to multidecadal timescales. Also, both the Pacific Decadal Oscillation (PDO) and the Atlantic Multidecadal Oscillation (AMO) modulate intermittently the interdecadal OHC variability in the North Pacific and Mid Atlantic, respectively. The NAO, through its influence on North Atlantic surface heat fluxes and convection, also plays an important role on the OHC at multiple timescales, leading first to a cooling in ... |
format |
Article in Journal/Newspaper |
author |
Ortega, P. Montoya, Marisa González-Rouco, J. F. Beltrami, H. Swingedouw, Didier |
author_facet |
Ortega, P. Montoya, Marisa González-Rouco, J. F. Beltrami, H. Swingedouw, Didier |
author_sort |
Ortega, P. |
title |
Variability of the ocean heat content during the last millennium – an assessment with the ECHO-g Model |
title_short |
Variability of the ocean heat content during the last millennium – an assessment with the ECHO-g Model |
title_full |
Variability of the ocean heat content during the last millennium – an assessment with the ECHO-g Model |
title_fullStr |
Variability of the ocean heat content during the last millennium – an assessment with the ECHO-g Model |
title_full_unstemmed |
Variability of the ocean heat content during the last millennium – an assessment with the ECHO-g Model |
title_sort |
variability of the ocean heat content during the last millennium – an assessment with the echo-g model |
publisher |
European Geosciences Union |
publishDate |
2013 |
url |
http://hdl.handle.net/10261/76905 https://doi.org/10.5194/cp-9-547-2013 |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_relation |
Publisher’s version http://dx.doi.org/10.5194/cp-9-547-2013 Ortega, P., Montoya, M., González-Rouco, F., Beltrami, H., & Swingedouw, D. (2013). Variability of the ocean heat content during the last millennium – an assessment with the ECHO-g Model. Climate of the Past, 9(2), 547–565. doi:10.5194/cp-9-547-2013 http://hdl.handle.net/10261/76905 doi:10.5194/cp-9-547-2013 |
op_rights |
open |
op_doi |
https://doi.org/10.5194/cp-9-547-2013 |
container_title |
Climate of the Past |
container_volume |
9 |
container_issue |
2 |
container_start_page |
547 |
op_container_end_page |
565 |
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1790603803412660224 |