The Atlantic Meridional Mode and Associated Wind–SST Relationship in the CMIP6 Models
The Atlantic Meridional Mode (AMM) is the dominant mode of interannual climate variability in the tropical Atlantic, maintained primarily by the positive wind–evaporation–sea surface temperature (SST) feedback in which the wind anomalies lead the SST anomalies by ~2 months. A previous study revealed...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-02-01
|
| Series: | Atmosphere |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-4433/14/2/359 |
| _version_ | 1797622396726804480 |
|---|---|
| author | Fannyu Xia Jinqing Zuo Chenghu Sun Ao Liu |
| author_facet | Fannyu Xia Jinqing Zuo Chenghu Sun Ao Liu |
| author_sort | Fannyu Xia |
| collection | DOAJ |
| description | The Atlantic Meridional Mode (AMM) is the dominant mode of interannual climate variability in the tropical Atlantic, maintained primarily by the positive wind–evaporation–sea surface temperature (SST) feedback in which the wind anomalies lead the SST anomalies by ~2 months. A previous study revealed that climate models from Coupled Model Intercomparison Project Phase 5 (CMIP5) show poor performance in simulating the AMM-related wind–SST relationship, but the possible causes remain unclear. This study assesses the representation of the AMM and associated wind–SST relationship in the climate models from CMIP6. Results show that most of the CMIP6 models can reasonably reproduce the observed spatial pattern of the AMM, with significant SST and wind anomalies in the northern tropical Atlantic and weak anomalies in the equatorial–southern oceans. However, the simulated wind–SST relationship associated with the AMM varies among the models. In particular, several models fail to capture the observed wind–SST relationship; that is, the simulated wind anomalies peak in boreal spring as in the observations, but no obvious peak occurs in the corresponding SST anomalies. Further analysis suggests the models that fail to capture the observed wind–SST relationship tend to simulate a stronger mean trade wind and a thicker mixed layer in the northern tropical Atlantic, leading to a weaker ocean–atmosphere coupling and, thus, a weaker SST response to the wind forcing. Moreover, there exists a significant out-of-phase relationship between the strength of ocean–atmosphere coupling and mean mixed layer depth among the models, supporting the impact of mean state biases on the AMM variability in the models. |
| first_indexed | 2024-03-11T09:09:41Z |
| format | Article |
| id | doaj.art-1f89db224a0d4e25a3afec812b499568 |
| institution | Directory Open Access Journal |
| issn | 2073-4433 |
| language | English |
| last_indexed | 2024-03-11T09:09:41Z |
| publishDate | 2023-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Atmosphere |
| spelling | doaj.art-1f89db224a0d4e25a3afec812b4995682023-11-16T19:03:45ZengMDPI AGAtmosphere2073-44332023-02-0114235910.3390/atmos14020359The Atlantic Meridional Mode and Associated Wind–SST Relationship in the CMIP6 ModelsFannyu Xia0Jinqing Zuo1Chenghu Sun2Ao Liu3State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, China Meteorological Administration, Beijing 100081, ChinaCollaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), Nanjing University of Information Science & Technology, Nanjing 210044, ChinaState Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, China Meteorological Administration, Beijing 100081, ChinaState Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, China Meteorological Administration, Beijing 100081, ChinaThe Atlantic Meridional Mode (AMM) is the dominant mode of interannual climate variability in the tropical Atlantic, maintained primarily by the positive wind–evaporation–sea surface temperature (SST) feedback in which the wind anomalies lead the SST anomalies by ~2 months. A previous study revealed that climate models from Coupled Model Intercomparison Project Phase 5 (CMIP5) show poor performance in simulating the AMM-related wind–SST relationship, but the possible causes remain unclear. This study assesses the representation of the AMM and associated wind–SST relationship in the climate models from CMIP6. Results show that most of the CMIP6 models can reasonably reproduce the observed spatial pattern of the AMM, with significant SST and wind anomalies in the northern tropical Atlantic and weak anomalies in the equatorial–southern oceans. However, the simulated wind–SST relationship associated with the AMM varies among the models. In particular, several models fail to capture the observed wind–SST relationship; that is, the simulated wind anomalies peak in boreal spring as in the observations, but no obvious peak occurs in the corresponding SST anomalies. Further analysis suggests the models that fail to capture the observed wind–SST relationship tend to simulate a stronger mean trade wind and a thicker mixed layer in the northern tropical Atlantic, leading to a weaker ocean–atmosphere coupling and, thus, a weaker SST response to the wind forcing. Moreover, there exists a significant out-of-phase relationship between the strength of ocean–atmosphere coupling and mean mixed layer depth among the models, supporting the impact of mean state biases on the AMM variability in the models.https://www.mdpi.com/2073-4433/14/2/359Atlantic Meridional Modewind–SST relationshipocean–atmosphere couplingCMIP6 |
| spellingShingle | Fannyu Xia Jinqing Zuo Chenghu Sun Ao Liu The Atlantic Meridional Mode and Associated Wind–SST Relationship in the CMIP6 Models Atmosphere Atlantic Meridional Mode wind–SST relationship ocean–atmosphere coupling CMIP6 |
| title | The Atlantic Meridional Mode and Associated Wind–SST Relationship in the CMIP6 Models |
| title_full | The Atlantic Meridional Mode and Associated Wind–SST Relationship in the CMIP6 Models |
| title_fullStr | The Atlantic Meridional Mode and Associated Wind–SST Relationship in the CMIP6 Models |
| title_full_unstemmed | The Atlantic Meridional Mode and Associated Wind–SST Relationship in the CMIP6 Models |
| title_short | The Atlantic Meridional Mode and Associated Wind–SST Relationship in the CMIP6 Models |
| title_sort | atlantic meridional mode and associated wind sst relationship in the cmip6 models |
| topic | Atlantic Meridional Mode wind–SST relationship ocean–atmosphere coupling CMIP6 |
| url | https://www.mdpi.com/2073-4433/14/2/359 |
| work_keys_str_mv | AT fannyuxia theatlanticmeridionalmodeandassociatedwindsstrelationshipinthecmip6models AT jinqingzuo theatlanticmeridionalmodeandassociatedwindsstrelationshipinthecmip6models AT chenghusun theatlanticmeridionalmodeandassociatedwindsstrelationshipinthecmip6models AT aoliu theatlanticmeridionalmodeandassociatedwindsstrelationshipinthecmip6models AT fannyuxia atlanticmeridionalmodeandassociatedwindsstrelationshipinthecmip6models AT jinqingzuo atlanticmeridionalmodeandassociatedwindsstrelationshipinthecmip6models AT chenghusun atlanticmeridionalmodeandassociatedwindsstrelationshipinthecmip6models AT aoliu atlanticmeridionalmodeandassociatedwindsstrelationshipinthecmip6models |