Physical mechanisms controlling self-aggregation of convection in idealized numerical modeling simulations
We elucidate the physics of self-aggregation by applying a new diagnostic technique to the output of a cloud resolving model. Specifically, the System for Atmospheric Modeling is used to perform 3- D cloud system resolving simulations of radiative-convective equilibrium in a nonrotating framework, w...
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
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American Geophysical Union (AGU)
2015
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| Online Access: | http://hdl.handle.net/1721.1/97935 https://orcid.org/0000-0003-2194-8709 https://orcid.org/0000-0002-2066-2082 |
| _version_ | 1826211431525122048 |
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| author | Wing, Allison A. Emanuel, Kerry Andrew |
| author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Wing, Allison A. Emanuel, Kerry Andrew |
| author_sort | Wing, Allison A. |
| collection | MIT |
| description | We elucidate the physics of self-aggregation by applying a new diagnostic technique to the output of a cloud resolving model. Specifically, the System for Atmospheric Modeling is used to perform 3- D cloud system resolving simulations of radiative-convective equilibrium in a nonrotating framework, with interactive radiation and surface fluxes and fixed sea surface temperature (SST). We note that self-aggregation begins as a dry patch that expands, eventually forcing all the convection into a single clump. Thus, when examining the initiation of self-aggregation, we focus on processes that can amplify this initial dry patch. We introduce a novel method to quantify the magnitudes of the various feedbacks that control self-aggregation within the framework of the budget for the spatial variance of column-integrated frozen moist static energy. The absorption of shortwave radiation by atmospheric water vapor is found to be a key positive feedback in the evolution of aggregation. In addition, we find a positive wind speed-surface flux feedback whose role is to counteract a negative feedback due to the effect of air-sea enthalpy disequilibrium on surface fluxes. The longwave radiation feedback can be either positive or negative in the early and intermediate stages of aggregation; however, it is the dominant positive feedback that maintains the aggregated state once it develops. Importantly, the mechanisms that maintain the aggregate state are distinct from those that instigate the evolution of self-aggregation. |
| first_indexed | 2024-09-23T15:06:06Z |
| format | Article |
| id | mit-1721.1/97935 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T15:06:06Z |
| publishDate | 2015 |
| publisher | American Geophysical Union (AGU) |
| record_format | dspace |
| spelling | mit-1721.1/979352022-09-29T12:40:39Z Physical mechanisms controlling self-aggregation of convection in idealized numerical modeling simulations Wing, Allison A. Emanuel, Kerry Andrew Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Massachusetts Institute of Technology. Program in Atmospheres, Oceans, and Climate Woods Hole Oceanographic Institution Wing, Allison A. Emanuel, Kerry Andrew We elucidate the physics of self-aggregation by applying a new diagnostic technique to the output of a cloud resolving model. Specifically, the System for Atmospheric Modeling is used to perform 3- D cloud system resolving simulations of radiative-convective equilibrium in a nonrotating framework, with interactive radiation and surface fluxes and fixed sea surface temperature (SST). We note that self-aggregation begins as a dry patch that expands, eventually forcing all the convection into a single clump. Thus, when examining the initiation of self-aggregation, we focus on processes that can amplify this initial dry patch. We introduce a novel method to quantify the magnitudes of the various feedbacks that control self-aggregation within the framework of the budget for the spatial variance of column-integrated frozen moist static energy. The absorption of shortwave radiation by atmospheric water vapor is found to be a key positive feedback in the evolution of aggregation. In addition, we find a positive wind speed-surface flux feedback whose role is to counteract a negative feedback due to the effect of air-sea enthalpy disequilibrium on surface fluxes. The longwave radiation feedback can be either positive or negative in the early and intermediate stages of aggregation; however, it is the dominant positive feedback that maintains the aggregated state once it develops. Importantly, the mechanisms that maintain the aggregate state are distinct from those that instigate the evolution of self-aggregation. National Science Foundation (U.S.) (Grant 1032244) National Science Foundation (U.S.) (Grant 1136480) National Science Foundation (U.S.) (Grant 0850639) Massachusetts Institute of Technology. Joint Program on the Science & Policy of Global Change 2015-07-31T17:20:11Z 2015-07-31T17:20:11Z 2014-02 2013-09 Article http://purl.org/eprint/type/JournalArticle 19422466 http://hdl.handle.net/1721.1/97935 Wing, Allison A., and Kerry A. Emanuel. “Physical Mechanisms Controlling Self-Aggregation of Convection in Idealized Numerical Modeling Simulations.” Journal of Advances in Modeling Earth Systems 6, no. 1 (February 5, 2014): 59–74. © 2014 American Geophysical Union https://orcid.org/0000-0003-2194-8709 https://orcid.org/0000-0002-2066-2082 en_US http://dx.doi.org/10.1002/2013ms000269 Journal of Advances in Modeling Earth Systems Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Geophysical Union (AGU) MIT web domain |
| spellingShingle | Wing, Allison A. Emanuel, Kerry Andrew Physical mechanisms controlling self-aggregation of convection in idealized numerical modeling simulations |
| title | Physical mechanisms controlling self-aggregation of convection in idealized numerical modeling simulations |
| title_full | Physical mechanisms controlling self-aggregation of convection in idealized numerical modeling simulations |
| title_fullStr | Physical mechanisms controlling self-aggregation of convection in idealized numerical modeling simulations |
| title_full_unstemmed | Physical mechanisms controlling self-aggregation of convection in idealized numerical modeling simulations |
| title_short | Physical mechanisms controlling self-aggregation of convection in idealized numerical modeling simulations |
| title_sort | physical mechanisms controlling self aggregation of convection in idealized numerical modeling simulations |
| url | http://hdl.handle.net/1721.1/97935 https://orcid.org/0000-0003-2194-8709 https://orcid.org/0000-0002-2066-2082 |
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