Re-emergence of North Atlantic subsurface ocean temperature anomalies in a seasonal forecast system
A high-resolution coupled ocean atmosphere model is used to study the effects of seasonal re-emergence of North Atlantic subsurface ocean temperature anomalies on northern hemisphere winter climate. A 50-member control ensemble is integrated from 1 September 2007 to 28 February 2008 and compared wit...
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Online Access: | https://eprints.soton.ac.uk/433305/ https://eprints.soton.ac.uk/433305/1/Grist2019_Article_Re_emergenceOfNorthAtlanticSub.pdf |
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ftsouthampton:oai:eprints.soton.ac.uk:433305 2023-07-30T04:05:20+02:00 Re-emergence of North Atlantic subsurface ocean temperature anomalies in a seasonal forecast system Grist, Jeremy P. Sinha, Bablu Hewitt, Helene. T. Duchez, Aurélie Maclachlan, Craig Hyder, Patrick Josey, Simon A. Hirschi, Joël J.-M. Blaker, Adam T. New, Adrian. L. Scaife, Adam A. Roberts, Chris D. 2019-06-04 text https://eprints.soton.ac.uk/433305/ https://eprints.soton.ac.uk/433305/1/Grist2019_Article_Re_emergenceOfNorthAtlanticSub.pdf en English eng https://eprints.soton.ac.uk/433305/1/Grist2019_Article_Re_emergenceOfNorthAtlanticSub.pdf Grist, Jeremy P., Sinha, Bablu, Hewitt, Helene. T., Duchez, Aurélie, Maclachlan, Craig, Hyder, Patrick, Josey, Simon A., Hirschi, Joël J.-M., Blaker, Adam T., New, Adrian. L., Scaife, Adam A. and Roberts, Chris D. (2019) Re-emergence of North Atlantic subsurface ocean temperature anomalies in a seasonal forecast system. Climate Dynamics, 1-22. (doi:10.1007/s00382-019-04826-w <http://dx.doi.org/10.1007/s00382-019-04826-w>). cc_by_4 Article PeerReviewed 2019 ftsouthampton https://doi.org/10.1007/s00382-019-04826-w 2023-07-09T22:31:19Z A high-resolution coupled ocean atmosphere model is used to study the effects of seasonal re-emergence of North Atlantic subsurface ocean temperature anomalies on northern hemisphere winter climate. A 50-member control ensemble is integrated from 1 September 2007 to 28 February 2008 and compared with a parallel ensemble with perturbed ocean initial conditions. The perturbation consists of a density-compensated subsurface Atlantic temperature anomaly corresponding to the observed subsurface temperature anomaly for September 2010. The experiment is repeated for two atmosphere horizontal resolutions (~ 60 km and ~ 25 km) in order to determine whether the sensitivity of the atmosphere to re-emerging temperature anomalies is dependent on resolution. A wide range of re-emergence behavior is found within the perturbed ensembles. While the observations seem to indicate that most of the re-emergence is occurring in November, most members of the ensemble show re-emergence occurring later in the winter. However, when re-emergence does occur it is preceded by an atmospheric pressure pattern that induces a strong flow of cold, dry air over the mid-latitude Atlantic, and enhances oceanic latent heat loss. In response to re-emergence (negative SST anomalies), there is reduced latent heat loss, less atmospheric convection, a reduction in eddy kinetic energy and positive low-level pressure anomalies downstream. Within the framework of a seasonal forecast system the results highlight the atmospheric conditions required for re-emergence to take place and the physical processes that may lead to a significant effect on the winter atmospheric circulation. Article in Journal/Newspaper North Atlantic University of Southampton: e-Prints Soton Climate Dynamics 53 7-8 4799 4820 |
institution |
Open Polar |
collection |
University of Southampton: e-Prints Soton |
op_collection_id |
ftsouthampton |
language |
English |
description |
A high-resolution coupled ocean atmosphere model is used to study the effects of seasonal re-emergence of North Atlantic subsurface ocean temperature anomalies on northern hemisphere winter climate. A 50-member control ensemble is integrated from 1 September 2007 to 28 February 2008 and compared with a parallel ensemble with perturbed ocean initial conditions. The perturbation consists of a density-compensated subsurface Atlantic temperature anomaly corresponding to the observed subsurface temperature anomaly for September 2010. The experiment is repeated for two atmosphere horizontal resolutions (~ 60 km and ~ 25 km) in order to determine whether the sensitivity of the atmosphere to re-emerging temperature anomalies is dependent on resolution. A wide range of re-emergence behavior is found within the perturbed ensembles. While the observations seem to indicate that most of the re-emergence is occurring in November, most members of the ensemble show re-emergence occurring later in the winter. However, when re-emergence does occur it is preceded by an atmospheric pressure pattern that induces a strong flow of cold, dry air over the mid-latitude Atlantic, and enhances oceanic latent heat loss. In response to re-emergence (negative SST anomalies), there is reduced latent heat loss, less atmospheric convection, a reduction in eddy kinetic energy and positive low-level pressure anomalies downstream. Within the framework of a seasonal forecast system the results highlight the atmospheric conditions required for re-emergence to take place and the physical processes that may lead to a significant effect on the winter atmospheric circulation. |
format |
Article in Journal/Newspaper |
author |
Grist, Jeremy P. Sinha, Bablu Hewitt, Helene. T. Duchez, Aurélie Maclachlan, Craig Hyder, Patrick Josey, Simon A. Hirschi, Joël J.-M. Blaker, Adam T. New, Adrian. L. Scaife, Adam A. Roberts, Chris D. |
spellingShingle |
Grist, Jeremy P. Sinha, Bablu Hewitt, Helene. T. Duchez, Aurélie Maclachlan, Craig Hyder, Patrick Josey, Simon A. Hirschi, Joël J.-M. Blaker, Adam T. New, Adrian. L. Scaife, Adam A. Roberts, Chris D. Re-emergence of North Atlantic subsurface ocean temperature anomalies in a seasonal forecast system |
author_facet |
Grist, Jeremy P. Sinha, Bablu Hewitt, Helene. T. Duchez, Aurélie Maclachlan, Craig Hyder, Patrick Josey, Simon A. Hirschi, Joël J.-M. Blaker, Adam T. New, Adrian. L. Scaife, Adam A. Roberts, Chris D. |
author_sort |
Grist, Jeremy P. |
title |
Re-emergence of North Atlantic subsurface ocean temperature anomalies in a seasonal forecast system |
title_short |
Re-emergence of North Atlantic subsurface ocean temperature anomalies in a seasonal forecast system |
title_full |
Re-emergence of North Atlantic subsurface ocean temperature anomalies in a seasonal forecast system |
title_fullStr |
Re-emergence of North Atlantic subsurface ocean temperature anomalies in a seasonal forecast system |
title_full_unstemmed |
Re-emergence of North Atlantic subsurface ocean temperature anomalies in a seasonal forecast system |
title_sort |
re-emergence of north atlantic subsurface ocean temperature anomalies in a seasonal forecast system |
publishDate |
2019 |
url |
https://eprints.soton.ac.uk/433305/ https://eprints.soton.ac.uk/433305/1/Grist2019_Article_Re_emergenceOfNorthAtlanticSub.pdf |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
https://eprints.soton.ac.uk/433305/1/Grist2019_Article_Re_emergenceOfNorthAtlanticSub.pdf Grist, Jeremy P., Sinha, Bablu, Hewitt, Helene. T., Duchez, Aurélie, Maclachlan, Craig, Hyder, Patrick, Josey, Simon A., Hirschi, Joël J.-M., Blaker, Adam T., New, Adrian. L., Scaife, Adam A. and Roberts, Chris D. (2019) Re-emergence of North Atlantic subsurface ocean temperature anomalies in a seasonal forecast system. Climate Dynamics, 1-22. (doi:10.1007/s00382-019-04826-w <http://dx.doi.org/10.1007/s00382-019-04826-w>). |
op_rights |
cc_by_4 |
op_doi |
https://doi.org/10.1007/s00382-019-04826-w |
container_title |
Climate Dynamics |
container_volume |
53 |
container_issue |
7-8 |
container_start_page |
4799 |
op_container_end_page |
4820 |
_version_ |
1772817181406396416 |