Northern Hemisphere atmospheric response to changes of Atlantic Ocean SST on decadal time scales: A GCM experiment
Analyses indicate that the Atlantic Ocean SST was considerably colder at the beginning than in the middle of the century. Parallel to this a systematic change of the North Atlantic SLP pattern was observed. To find out whether the analyzed SST and SLP changes are consistent, which would indicate that...
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ftpubman:oai:pure.mpg.de:item_2565741 2023-08-27T04:11:01+02:00 Northern Hemisphere atmospheric response to changes of Atlantic Ocean SST on decadal time scales: A GCM experiment Hense, A. Glowienka-Hense, R. von Storch, H. Stähler, U. 1990 application/pdf http://hdl.handle.net/21.11116/0000-0001-2BB8-0 http://hdl.handle.net/21.11116/0000-0001-2BBA-E http://hdl.handle.net/21.11116/0000-0009-FADC-6 eng eng info:eu-repo/semantics/altIdentifier/doi/10.1007/BF00209519 http://hdl.handle.net/21.11116/0000-0001-2BB8-0 http://hdl.handle.net/21.11116/0000-0001-2BBA-E http://hdl.handle.net/21.11116/0000-0009-FADC-6 info:eu-repo/semantics/openAccess Climate Dynamics Report / Max-Planck-Institut für Meteorologie info:eu-repo/semantics/article 1990 ftpubman https://doi.org/10.1007/BF00209519 2023-08-02T00:57:10Z Analyses indicate that the Atlantic Ocean SST was considerably colder at the beginning than in the middle of the century. Parallel to this a systematic change of the North Atlantic SLP pattern was observed. To find out whether the analyzed SST and SLP changes are consistent, which would indicate that the SST change was real and not an instrumental artifact, a response experiment with a low resolution (T21) atmospheric GCM was performed. Two perpetual January simulations were conducted which differ solely in Atlantic Ocean (40$ - 60N) SST: the ”cold” simulation utilizes the SSTs for the period 1904-13, the ”warm” simulation uses the SST’s for the period 1951—60. Also a ”control” run, with the model’s standard SST somewhat between the ”cold” and ”warm” SST, was made. For the response analysis a rigorous statistical approach was taken: First the null hypothesis of identical horizontal distributions was subjected to a multivariate significance test. Second, the level of recurrence was estimated. The multivariate statistical approaches are based on hierarchies of test models. We examined three different hierarchies: a scale dependent hierarchy based on spherical harmonics (S), and two physically motivated ones, one based on the barotropic normal modes of the mean 300 hPa flow (B) and one based on the eigenmodes of the advection diffusion operator at 1000 hPa (A). The intercomparison of the ”cold” and ”warm” experiments indicates a signal in the geostrophic stream function that is in the S-hierarchy significantly nonzero and highly recurrent. In the A—hierarchy, the low level temperature field is identi— fied as being significantly and recurrently affected by the altered SST distribution. The SLP signal is reasonably similar to the observed SLP change. Unexpectedly the upper level streamfunction signal does not appear significantly nonzero in the B—hierarchy. If, however the pairs of experiments ”warm vs. control” and ”cold vs. control” are examined in the B—hierarchy, a highly significant and recurrent signal emerges. We ... Article in Journal/Newspaper North Atlantic Max Planck Society: MPG.PuRe Climate Dynamics 4 3 157 174 |
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Open Polar |
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Max Planck Society: MPG.PuRe |
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ftpubman |
language |
English |
description |
Analyses indicate that the Atlantic Ocean SST was considerably colder at the beginning than in the middle of the century. Parallel to this a systematic change of the North Atlantic SLP pattern was observed. To find out whether the analyzed SST and SLP changes are consistent, which would indicate that the SST change was real and not an instrumental artifact, a response experiment with a low resolution (T21) atmospheric GCM was performed. Two perpetual January simulations were conducted which differ solely in Atlantic Ocean (40$ - 60N) SST: the ”cold” simulation utilizes the SSTs for the period 1904-13, the ”warm” simulation uses the SST’s for the period 1951—60. Also a ”control” run, with the model’s standard SST somewhat between the ”cold” and ”warm” SST, was made. For the response analysis a rigorous statistical approach was taken: First the null hypothesis of identical horizontal distributions was subjected to a multivariate significance test. Second, the level of recurrence was estimated. The multivariate statistical approaches are based on hierarchies of test models. We examined three different hierarchies: a scale dependent hierarchy based on spherical harmonics (S), and two physically motivated ones, one based on the barotropic normal modes of the mean 300 hPa flow (B) and one based on the eigenmodes of the advection diffusion operator at 1000 hPa (A). The intercomparison of the ”cold” and ”warm” experiments indicates a signal in the geostrophic stream function that is in the S-hierarchy significantly nonzero and highly recurrent. In the A—hierarchy, the low level temperature field is identi— fied as being significantly and recurrently affected by the altered SST distribution. The SLP signal is reasonably similar to the observed SLP change. Unexpectedly the upper level streamfunction signal does not appear significantly nonzero in the B—hierarchy. If, however the pairs of experiments ”warm vs. control” and ”cold vs. control” are examined in the B—hierarchy, a highly significant and recurrent signal emerges. We ... |
format |
Article in Journal/Newspaper |
author |
Hense, A. Glowienka-Hense, R. von Storch, H. Stähler, U. |
spellingShingle |
Hense, A. Glowienka-Hense, R. von Storch, H. Stähler, U. Northern Hemisphere atmospheric response to changes of Atlantic Ocean SST on decadal time scales: A GCM experiment |
author_facet |
Hense, A. Glowienka-Hense, R. von Storch, H. Stähler, U. |
author_sort |
Hense, A. |
title |
Northern Hemisphere atmospheric response to changes of Atlantic Ocean SST on decadal time scales: A GCM experiment |
title_short |
Northern Hemisphere atmospheric response to changes of Atlantic Ocean SST on decadal time scales: A GCM experiment |
title_full |
Northern Hemisphere atmospheric response to changes of Atlantic Ocean SST on decadal time scales: A GCM experiment |
title_fullStr |
Northern Hemisphere atmospheric response to changes of Atlantic Ocean SST on decadal time scales: A GCM experiment |
title_full_unstemmed |
Northern Hemisphere atmospheric response to changes of Atlantic Ocean SST on decadal time scales: A GCM experiment |
title_sort |
northern hemisphere atmospheric response to changes of atlantic ocean sst on decadal time scales: a gcm experiment |
publishDate |
1990 |
url |
http://hdl.handle.net/21.11116/0000-0001-2BB8-0 http://hdl.handle.net/21.11116/0000-0001-2BBA-E http://hdl.handle.net/21.11116/0000-0009-FADC-6 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Climate Dynamics Report / Max-Planck-Institut für Meteorologie |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1007/BF00209519 http://hdl.handle.net/21.11116/0000-0001-2BB8-0 http://hdl.handle.net/21.11116/0000-0001-2BBA-E http://hdl.handle.net/21.11116/0000-0009-FADC-6 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1007/BF00209519 |
container_title |
Climate Dynamics |
container_volume |
4 |
container_issue |
3 |
container_start_page |
157 |
op_container_end_page |
174 |
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1775353457375444992 |