Role of the mean state for the Southern Hemispheric jet stream response to CO2 forcing in CMIP6 models
Global climate models indicate that the Southern Hemispheric (SH) jet stream shifts poleward in response to CO _2 forcing, but the magnitude of this shift remains highly uncertain. Here we analyse the SH jet stream response to 4×CO _2 forcing in Coupled Model Intercomparison Project phase 6 (CMIP6)...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2020-01-01
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| Series: | Environmental Research Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1748-9326/ab8331 |
| _version_ | 1827869988937007104 |
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| author | Paul Edwin Curtis Paulo Ceppi Giuseppe Zappa |
| author_facet | Paul Edwin Curtis Paulo Ceppi Giuseppe Zappa |
| author_sort | Paul Edwin Curtis |
| collection | DOAJ |
| description | Global climate models indicate that the Southern Hemispheric (SH) jet stream shifts poleward in response to CO _2 forcing, but the magnitude of this shift remains highly uncertain. Here we analyse the SH jet stream response to 4×CO _2 forcing in Coupled Model Intercomparison Project phase 6 (CMIP6) simulations, and find a substantially muted jet shift during winter compared with CMIP5. We suggest this muted response results from a more poleward mean jet position, consistent with a strongly reduced bias in jet position relative to the reanalysis during 1980–2004. The improved mean jet position cannot be explained by changes in the simulated sea surface temperatures. Instead, we find indications that increased horizontal grid resolution in CMIP6 relative to CMIP5 has contributed to the higher mean jet latitude, and thus to the reduced jet shift under CO _2 forcing. These results imply that CMIP6 models can provide more realistic projections of SH climate change. |
| first_indexed | 2024-03-12T15:52:23Z |
| format | Article |
| id | doaj.art-facb9ca8a78647e09f6fbe8c5fd31bf3 |
| institution | Directory Open Access Journal |
| issn | 1748-9326 |
| language | English |
| last_indexed | 2024-03-12T15:52:23Z |
| publishDate | 2020-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj.art-facb9ca8a78647e09f6fbe8c5fd31bf32023-08-09T15:07:48ZengIOP PublishingEnvironmental Research Letters1748-93262020-01-0115606401110.1088/1748-9326/ab8331Role of the mean state for the Southern Hemispheric jet stream response to CO2 forcing in CMIP6 modelsPaul Edwin Curtis0Paulo Ceppi1https://orcid.org/0000-0002-3754-3506Giuseppe Zappa2https://orcid.org/0000-0003-4306-7451Department of Physics, Imperial College London , London, United KingdomGrantham Institute for Climate Change and the Environment, Imperial College London , London, United KingdomIstituto di Scienze dell’Atmosfera e del Clima (ISAC), Consiglio Nazionale delle Ricerche (CNR) , Bologna, ItalyGlobal climate models indicate that the Southern Hemispheric (SH) jet stream shifts poleward in response to CO _2 forcing, but the magnitude of this shift remains highly uncertain. Here we analyse the SH jet stream response to 4×CO _2 forcing in Coupled Model Intercomparison Project phase 6 (CMIP6) simulations, and find a substantially muted jet shift during winter compared with CMIP5. We suggest this muted response results from a more poleward mean jet position, consistent with a strongly reduced bias in jet position relative to the reanalysis during 1980–2004. The improved mean jet position cannot be explained by changes in the simulated sea surface temperatures. Instead, we find indications that increased horizontal grid resolution in CMIP6 relative to CMIP5 has contributed to the higher mean jet latitude, and thus to the reduced jet shift under CO _2 forcing. These results imply that CMIP6 models can provide more realistic projections of SH climate change.https://doi.org/10.1088/1748-9326/ab8331climate changeatmospheric circulationjet streamsclimate models |
| spellingShingle | Paul Edwin Curtis Paulo Ceppi Giuseppe Zappa Role of the mean state for the Southern Hemispheric jet stream response to CO2 forcing in CMIP6 models Environmental Research Letters climate change atmospheric circulation jet streams climate models |
| title | Role of the mean state for the Southern Hemispheric jet stream response to CO2 forcing in CMIP6 models |
| title_full | Role of the mean state for the Southern Hemispheric jet stream response to CO2 forcing in CMIP6 models |
| title_fullStr | Role of the mean state for the Southern Hemispheric jet stream response to CO2 forcing in CMIP6 models |
| title_full_unstemmed | Role of the mean state for the Southern Hemispheric jet stream response to CO2 forcing in CMIP6 models |
| title_short | Role of the mean state for the Southern Hemispheric jet stream response to CO2 forcing in CMIP6 models |
| title_sort | role of the mean state for the southern hemispheric jet stream response to co2 forcing in cmip6 models |
| topic | climate change atmospheric circulation jet streams climate models |
| url | https://doi.org/10.1088/1748-9326/ab8331 |
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