Inter‐model comparison of subseasonal tropical variability in aquaplanet experiments: Effect of a warm pool
Abstract This study compares the simulation of subseasonal tropical variability by a set of six state‐of‐the‐art AGCMs in two experiments in aquaplanet configuration: a zonally symmetric experiment, and an experiment with a warm pool centered on the equator. In all six models, the presence of the wa...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
American Geophysical Union (AGU)
2016-12-01
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| Series: | Journal of Advances in Modeling Earth Systems |
| Subjects: | |
| Online Access: | https://doi.org/10.1002/2016MS000683 |
| _version_ | 1819107889282809856 |
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| author | Stephanie Leroux Gilles Bellon Romain Roehrig Mihaela Caian Nicholas P. Klingaman Jean‐Philippe Lafore Ionela Musat Catherine Rio Sophie Tyteca |
| author_facet | Stephanie Leroux Gilles Bellon Romain Roehrig Mihaela Caian Nicholas P. Klingaman Jean‐Philippe Lafore Ionela Musat Catherine Rio Sophie Tyteca |
| author_sort | Stephanie Leroux |
| collection | DOAJ |
| description | Abstract This study compares the simulation of subseasonal tropical variability by a set of six state‐of‐the‐art AGCMs in two experiments in aquaplanet configuration: a zonally symmetric experiment, and an experiment with a warm pool centered on the equator. In all six models, the presence of the warm pool generates zonal asymmetries in the simulated mean states in the form of a “Gill‐type” response, made more complex by feedbacks between moisture, convective heating and circulation. Noticeable differences appear from one model to another. Only half the models simulate mean low‐level equatorial westerlies over the warm pool area. The presence of the warm pool can also favor the development of large‐scale variability consistent with observed Madden‐Julian Oscillation (MJO) characteristics, but this happens only in half the models. Our results do not support the idea that the presence of the warm pool and/or of mean low‐level equatorial westerlies are sufficient conditions for MJO‐like variability to arise in the models. Comparing spectral characteristics of the simulated Convectively Coupled Equatorial Waves (CCEWs) in the aquaplanet experiments and the corresponding coupled atmosphere‐ocean (i.e., CMIP) and atmosphere‐only (i.e., AMIP) simulations, we also show that there is more consistency for a given model across its configurations, than for a given configuration across the six models. Overall, our results confirm that the simulation of subseasonal variability by given model is significantly influenced by the parameterization of subgrid physical processes (most‐likely cloud processes), both directly and through modulation of the mean state. |
| first_indexed | 2024-12-22T03:01:12Z |
| format | Article |
| id | doaj.art-b772b6fae0174b269e9c33faef780d36 |
| institution | Directory Open Access Journal |
| issn | 1942-2466 |
| language | English |
| last_indexed | 2024-12-22T03:01:12Z |
| publishDate | 2016-12-01 |
| publisher | American Geophysical Union (AGU) |
| record_format | Article |
| series | Journal of Advances in Modeling Earth Systems |
| spelling | doaj.art-b772b6fae0174b269e9c33faef780d362022-12-21T18:41:11ZengAmerican Geophysical Union (AGU)Journal of Advances in Modeling Earth Systems1942-24662016-12-01841526155110.1002/2016MS000683Inter‐model comparison of subseasonal tropical variability in aquaplanet experiments: Effect of a warm poolStephanie Leroux0Gilles Bellon1Romain Roehrig2Mihaela Caian3Nicholas P. Klingaman4Jean‐Philippe Lafore5Ionela Musat6Catherine Rio7Sophie Tyteca8CNRM UMR 3589Météo‐France/CNRSToulouse FranceCNRM UMR 3589Météo‐France/CNRSToulouse FranceCNRM UMR 3589Météo‐France/CNRSToulouse FranceSMHINorrköping SwedenNational Centre for Atmospheric Science‐Climate and Department of MeteorologyUniversity of ReadingReading UKCNRM UMR 3589Météo‐France/CNRSToulouse FranceLaboratoire de Météorologie Dynamique/IPSL/UPMC/CNRSLaboratoire de Météorologie Dynamique/IPSL/UPMC/CNRSCNRM UMR 3589Météo‐France/CNRSToulouse FranceAbstract This study compares the simulation of subseasonal tropical variability by a set of six state‐of‐the‐art AGCMs in two experiments in aquaplanet configuration: a zonally symmetric experiment, and an experiment with a warm pool centered on the equator. In all six models, the presence of the warm pool generates zonal asymmetries in the simulated mean states in the form of a “Gill‐type” response, made more complex by feedbacks between moisture, convective heating and circulation. Noticeable differences appear from one model to another. Only half the models simulate mean low‐level equatorial westerlies over the warm pool area. The presence of the warm pool can also favor the development of large‐scale variability consistent with observed Madden‐Julian Oscillation (MJO) characteristics, but this happens only in half the models. Our results do not support the idea that the presence of the warm pool and/or of mean low‐level equatorial westerlies are sufficient conditions for MJO‐like variability to arise in the models. Comparing spectral characteristics of the simulated Convectively Coupled Equatorial Waves (CCEWs) in the aquaplanet experiments and the corresponding coupled atmosphere‐ocean (i.e., CMIP) and atmosphere‐only (i.e., AMIP) simulations, we also show that there is more consistency for a given model across its configurations, than for a given configuration across the six models. Overall, our results confirm that the simulation of subseasonal variability by given model is significantly influenced by the parameterization of subgrid physical processes (most‐likely cloud processes), both directly and through modulation of the mean state.https://doi.org/10.1002/2016MS000683aquaplanettropical variabilityinter‐model comparisonMadden Julian OscillationMJO |
| spellingShingle | Stephanie Leroux Gilles Bellon Romain Roehrig Mihaela Caian Nicholas P. Klingaman Jean‐Philippe Lafore Ionela Musat Catherine Rio Sophie Tyteca Inter‐model comparison of subseasonal tropical variability in aquaplanet experiments: Effect of a warm pool Journal of Advances in Modeling Earth Systems aquaplanet tropical variability inter‐model comparison Madden Julian Oscillation MJO |
| title | Inter‐model comparison of subseasonal tropical variability in aquaplanet experiments: Effect of a warm pool |
| title_full | Inter‐model comparison of subseasonal tropical variability in aquaplanet experiments: Effect of a warm pool |
| title_fullStr | Inter‐model comparison of subseasonal tropical variability in aquaplanet experiments: Effect of a warm pool |
| title_full_unstemmed | Inter‐model comparison of subseasonal tropical variability in aquaplanet experiments: Effect of a warm pool |
| title_short | Inter‐model comparison of subseasonal tropical variability in aquaplanet experiments: Effect of a warm pool |
| title_sort | inter model comparison of subseasonal tropical variability in aquaplanet experiments effect of a warm pool |
| topic | aquaplanet tropical variability inter‐model comparison Madden Julian Oscillation MJO |
| url | https://doi.org/10.1002/2016MS000683 |
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