Process-level improvements in CMIP5 models and their impact on tropical variability, the Southern Ocean, and monsoons
The performance of updated versions of the four earth system models (ESMs) CNRM, EC-Earth, HadGEM, and MPI-ESM is assessed in comparison to their predecessor versions used in Phase 5 of the Coupled Model Intercomparison Project. The Earth System Model Evaluation Tool (ESMValTool) is applied to evalu...
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ftdoajarticles:oai:doaj.org/article:2cf17fbb0b0e401a9850b3a6d2b4c0d4 2023-05-15T18:24:56+02:00 Process-level improvements in CMIP5 models and their impact on tropical variability, the Southern Ocean, and monsoons A. Lauer C. Jones V. Eyring M. Evaldsson S. Hagemann J. Mäkelä G. Martin R. Roehrig S. Wang 2018-01-01T00:00:00Z https://doi.org/10.5194/esd-9-33-2018 https://doaj.org/article/2cf17fbb0b0e401a9850b3a6d2b4c0d4 EN eng Copernicus Publications https://www.earth-syst-dynam.net/9/33/2018/esd-9-33-2018.pdf https://doaj.org/toc/2190-4979 https://doaj.org/toc/2190-4987 doi:10.5194/esd-9-33-2018 2190-4979 2190-4987 https://doaj.org/article/2cf17fbb0b0e401a9850b3a6d2b4c0d4 Earth System Dynamics, Vol 9, Pp 33-67 (2018) Science Q Geology QE1-996.5 Dynamic and structural geology QE500-639.5 article 2018 ftdoajarticles https://doi.org/10.5194/esd-9-33-2018 2022-12-31T12:39:44Z The performance of updated versions of the four earth system models (ESMs) CNRM, EC-Earth, HadGEM, and MPI-ESM is assessed in comparison to their predecessor versions used in Phase 5 of the Coupled Model Intercomparison Project. The Earth System Model Evaluation Tool (ESMValTool) is applied to evaluate selected climate phenomena in the models against observations. This is the first systematic application of the ESMValTool to assess and document the progress made during an extensive model development and improvement project. This study focuses on the South Asian monsoon (SAM) and the West African monsoon (WAM), the coupled equatorial climate, and Southern Ocean clouds and radiation, which are known to exhibit systematic biases in present-day ESMs. The analysis shows that the tropical precipitation in three out of four models is clearly improved. Two of three updated coupled models show an improved representation of tropical sea surface temperatures with one coupled model not exhibiting a double Intertropical Convergence Zone (ITCZ). Simulated cloud amounts and cloud–radiation interactions are improved over the Southern Ocean. Improvements are also seen in the simulation of the SAM and WAM, although systematic biases remain in regional details and the timing of monsoon rainfall. Analysis of simulations with EC-Earth at different horizontal resolutions from T159 up to T1279 shows that the synoptic-scale variability in precipitation over the SAM and WAM regions improves with higher model resolution. The results suggest that the reasonably good agreement of modeled and observed mean WAM and SAM rainfall in lower-resolution models may be a result of unrealistic intensity distributions. Article in Journal/Newspaper Southern Ocean Directory of Open Access Journals: DOAJ Articles Southern Ocean Earth System Dynamics 9 1 33 67 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Science Q Geology QE1-996.5 Dynamic and structural geology QE500-639.5 |
spellingShingle |
Science Q Geology QE1-996.5 Dynamic and structural geology QE500-639.5 A. Lauer C. Jones V. Eyring M. Evaldsson S. Hagemann J. Mäkelä G. Martin R. Roehrig S. Wang Process-level improvements in CMIP5 models and their impact on tropical variability, the Southern Ocean, and monsoons |
topic_facet |
Science Q Geology QE1-996.5 Dynamic and structural geology QE500-639.5 |
description |
The performance of updated versions of the four earth system models (ESMs) CNRM, EC-Earth, HadGEM, and MPI-ESM is assessed in comparison to their predecessor versions used in Phase 5 of the Coupled Model Intercomparison Project. The Earth System Model Evaluation Tool (ESMValTool) is applied to evaluate selected climate phenomena in the models against observations. This is the first systematic application of the ESMValTool to assess and document the progress made during an extensive model development and improvement project. This study focuses on the South Asian monsoon (SAM) and the West African monsoon (WAM), the coupled equatorial climate, and Southern Ocean clouds and radiation, which are known to exhibit systematic biases in present-day ESMs. The analysis shows that the tropical precipitation in three out of four models is clearly improved. Two of three updated coupled models show an improved representation of tropical sea surface temperatures with one coupled model not exhibiting a double Intertropical Convergence Zone (ITCZ). Simulated cloud amounts and cloud–radiation interactions are improved over the Southern Ocean. Improvements are also seen in the simulation of the SAM and WAM, although systematic biases remain in regional details and the timing of monsoon rainfall. Analysis of simulations with EC-Earth at different horizontal resolutions from T159 up to T1279 shows that the synoptic-scale variability in precipitation over the SAM and WAM regions improves with higher model resolution. The results suggest that the reasonably good agreement of modeled and observed mean WAM and SAM rainfall in lower-resolution models may be a result of unrealistic intensity distributions. |
format |
Article in Journal/Newspaper |
author |
A. Lauer C. Jones V. Eyring M. Evaldsson S. Hagemann J. Mäkelä G. Martin R. Roehrig S. Wang |
author_facet |
A. Lauer C. Jones V. Eyring M. Evaldsson S. Hagemann J. Mäkelä G. Martin R. Roehrig S. Wang |
author_sort |
A. Lauer |
title |
Process-level improvements in CMIP5 models and their impact on tropical variability, the Southern Ocean, and monsoons |
title_short |
Process-level improvements in CMIP5 models and their impact on tropical variability, the Southern Ocean, and monsoons |
title_full |
Process-level improvements in CMIP5 models and their impact on tropical variability, the Southern Ocean, and monsoons |
title_fullStr |
Process-level improvements in CMIP5 models and their impact on tropical variability, the Southern Ocean, and monsoons |
title_full_unstemmed |
Process-level improvements in CMIP5 models and their impact on tropical variability, the Southern Ocean, and monsoons |
title_sort |
process-level improvements in cmip5 models and their impact on tropical variability, the southern ocean, and monsoons |
publisher |
Copernicus Publications |
publishDate |
2018 |
url |
https://doi.org/10.5194/esd-9-33-2018 https://doaj.org/article/2cf17fbb0b0e401a9850b3a6d2b4c0d4 |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
Earth System Dynamics, Vol 9, Pp 33-67 (2018) |
op_relation |
https://www.earth-syst-dynam.net/9/33/2018/esd-9-33-2018.pdf https://doaj.org/toc/2190-4979 https://doaj.org/toc/2190-4987 doi:10.5194/esd-9-33-2018 2190-4979 2190-4987 https://doaj.org/article/2cf17fbb0b0e401a9850b3a6d2b4c0d4 |
op_doi |
https://doi.org/10.5194/esd-9-33-2018 |
container_title |
Earth System Dynamics |
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9 |
container_issue |
1 |
container_start_page |
33 |
op_container_end_page |
67 |
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1766205967368716288 |