Influence of initial ocean conditions on temperature and precipitation in a coupled climate model's solution
This paper describes results of an experiment that perturbed the initial conditions for the ocean's temperature field of the Community Earth System Model (CESM) with a well defined design. The resulting 30-member ensemble of CESM simulations, each of 10 years in length, is used to create an emu...
Published in: | Advances in Statistical Climatology, Meteorology and Oceanography |
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ftdoajarticles:oai:doaj.org/article:42b31c0e254548a8a7eb92e769b996e9 2023-05-15T13:40:34+02:00 Influence of initial ocean conditions on temperature and precipitation in a coupled climate model's solution R. Tokmakian P. Challenor 2019-03-01T00:00:00Z https://doi.org/10.5194/ascmo-5-17-2019 https://doaj.org/article/42b31c0e254548a8a7eb92e769b996e9 EN eng Copernicus Publications https://www.adv-stat-clim-meteorol-oceanogr.net/5/17/2019/ascmo-5-17-2019.pdf https://doaj.org/toc/2364-3579 https://doaj.org/toc/2364-3587 doi:10.5194/ascmo-5-17-2019 2364-3579 2364-3587 https://doaj.org/article/42b31c0e254548a8a7eb92e769b996e9 Advances in Statistical Climatology, Meteorology and Oceanography, Vol 5, Pp 17-35 (2019) Oceanography GC1-1581 Meteorology. Climatology QC851-999 Probabilities. Mathematical statistics QA273-280 article 2019 ftdoajarticles https://doi.org/10.5194/ascmo-5-17-2019 2022-12-31T14:12:15Z This paper describes results of an experiment that perturbed the initial conditions for the ocean's temperature field of the Community Earth System Model (CESM) with a well defined design. The resulting 30-member ensemble of CESM simulations, each of 10 years in length, is used to create an emulator (a nonlinear regression relating the initial conditions to various outcomes) from the simulators. Through the use of the emulator to expand the output distribution space, we estimate the spatial uncertainties at 10 years for surface air temperature, 25 m ocean temperature, precipitation, and rain. Outside the tropics, basin averages for the uncertainty in the ocean temperature field range between 0.48 ∘ C (Indian Ocean) and 0.87 ∘ C (North Pacific) (2 standard deviation). The tropical Pacific uncertainty is the largest due to different phasings of the ENSO signal. Over land areas, the regional temperature uncertainty varies from 1.03 ∘ C (South America) to 10.82 ∘ C (Europe) (2 standard deviation). Similarly, the regional average uncertainty in precipitation varies from 0.001 cm day −1 over Antarctica to 0.163 cm day −1 over Australia with a global average of 0.075 cm day −1 . In general, both temperature and precipitation uncertainties are larger over land than over the ocean. A maximum covariance analysis is used to examine how ocean temperatures affect both surface air temperatures and precipitation over land. The analysis shows that the tropical Pacific influences the temperature over North America, but the North America surface temperature is also moderated by the state of the North Pacific outside the tropics. It also indicates which regions show a high degree of variance between the simulations in the ensemble and are, therefore, less predictable. The calculated uncertainties are also compared to an estimate of internal variability within CESM. Finally, the importance of feedback processes on the solution of the simulation over the 10 years of the experiment is quantified. These estimates of uncertainty do not ... Article in Journal/Newspaper Antarc* Antarctica Directory of Open Access Journals: DOAJ Articles Pacific Indian Advances in Statistical Climatology, Meteorology and Oceanography 5 1 17 35 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Oceanography GC1-1581 Meteorology. Climatology QC851-999 Probabilities. Mathematical statistics QA273-280 |
spellingShingle |
Oceanography GC1-1581 Meteorology. Climatology QC851-999 Probabilities. Mathematical statistics QA273-280 R. Tokmakian P. Challenor Influence of initial ocean conditions on temperature and precipitation in a coupled climate model's solution |
topic_facet |
Oceanography GC1-1581 Meteorology. Climatology QC851-999 Probabilities. Mathematical statistics QA273-280 |
description |
This paper describes results of an experiment that perturbed the initial conditions for the ocean's temperature field of the Community Earth System Model (CESM) with a well defined design. The resulting 30-member ensemble of CESM simulations, each of 10 years in length, is used to create an emulator (a nonlinear regression relating the initial conditions to various outcomes) from the simulators. Through the use of the emulator to expand the output distribution space, we estimate the spatial uncertainties at 10 years for surface air temperature, 25 m ocean temperature, precipitation, and rain. Outside the tropics, basin averages for the uncertainty in the ocean temperature field range between 0.48 ∘ C (Indian Ocean) and 0.87 ∘ C (North Pacific) (2 standard deviation). The tropical Pacific uncertainty is the largest due to different phasings of the ENSO signal. Over land areas, the regional temperature uncertainty varies from 1.03 ∘ C (South America) to 10.82 ∘ C (Europe) (2 standard deviation). Similarly, the regional average uncertainty in precipitation varies from 0.001 cm day −1 over Antarctica to 0.163 cm day −1 over Australia with a global average of 0.075 cm day −1 . In general, both temperature and precipitation uncertainties are larger over land than over the ocean. A maximum covariance analysis is used to examine how ocean temperatures affect both surface air temperatures and precipitation over land. The analysis shows that the tropical Pacific influences the temperature over North America, but the North America surface temperature is also moderated by the state of the North Pacific outside the tropics. It also indicates which regions show a high degree of variance between the simulations in the ensemble and are, therefore, less predictable. The calculated uncertainties are also compared to an estimate of internal variability within CESM. Finally, the importance of feedback processes on the solution of the simulation over the 10 years of the experiment is quantified. These estimates of uncertainty do not ... |
format |
Article in Journal/Newspaper |
author |
R. Tokmakian P. Challenor |
author_facet |
R. Tokmakian P. Challenor |
author_sort |
R. Tokmakian |
title |
Influence of initial ocean conditions on temperature and precipitation in a coupled climate model's solution |
title_short |
Influence of initial ocean conditions on temperature and precipitation in a coupled climate model's solution |
title_full |
Influence of initial ocean conditions on temperature and precipitation in a coupled climate model's solution |
title_fullStr |
Influence of initial ocean conditions on temperature and precipitation in a coupled climate model's solution |
title_full_unstemmed |
Influence of initial ocean conditions on temperature and precipitation in a coupled climate model's solution |
title_sort |
influence of initial ocean conditions on temperature and precipitation in a coupled climate model's solution |
publisher |
Copernicus Publications |
publishDate |
2019 |
url |
https://doi.org/10.5194/ascmo-5-17-2019 https://doaj.org/article/42b31c0e254548a8a7eb92e769b996e9 |
geographic |
Pacific Indian |
geographic_facet |
Pacific Indian |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_source |
Advances in Statistical Climatology, Meteorology and Oceanography, Vol 5, Pp 17-35 (2019) |
op_relation |
https://www.adv-stat-clim-meteorol-oceanogr.net/5/17/2019/ascmo-5-17-2019.pdf https://doaj.org/toc/2364-3579 https://doaj.org/toc/2364-3587 doi:10.5194/ascmo-5-17-2019 2364-3579 2364-3587 https://doaj.org/article/42b31c0e254548a8a7eb92e769b996e9 |
op_doi |
https://doi.org/10.5194/ascmo-5-17-2019 |
container_title |
Advances in Statistical Climatology, Meteorology and Oceanography |
container_volume |
5 |
container_issue |
1 |
container_start_page |
17 |
op_container_end_page |
35 |
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