دورية أكاديمية
How Wind Shear Affects Trade-wind Cumulus Convection.
| العنوان: | How Wind Shear Affects Trade-wind Cumulus Convection. |
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| المؤلفون: | Helfer KC; Department of Geoscience and Remote Sensing Delft University of Technology Delft Netherlands., Nuijens L; Department of Geoscience and Remote Sensing Delft University of Technology Delft Netherlands., de Roode SR; Department of Geoscience and Remote Sensing Delft University of Technology Delft Netherlands., Siebesma AP; Department of Geoscience and Remote Sensing Delft University of Technology Delft Netherlands.; Royal Netherlands Meteorological Institute (KNMI) De Bilt Netherlands. |
| المصدر: | Journal of advances in modeling earth systems [J Adv Model Earth Syst] 2020 Dec; Vol. 12 (12), pp. e2020MS002183. Date of Electronic Publication: 2020 Nov 28. |
| نوع المنشور: | Journal Article |
| اللغة: | English |
| بيانات الدورية: | Publisher: Wiley-Blackwell Country of Publication: United States NLM ID: 101691496 Publication Model: Print-Electronic Cited Medium: Print ISSN: 1942-2466 (Print) Linking ISSN: 19422466 NLM ISO Abbreviation: J Adv Model Earth Syst Subsets: PubMed not MEDLINE |
| أسماء مطبوعة: | Publication: 2013- : Malden, MA : Wiley-Blackwell Original Publication: Calverton, MD : Institute of Global Environment and Society, 2009- |
| مستخلص: | Motivated by an observed relationship between marine low cloud cover and surface wind speed, this study investigates how vertical wind shear affects trade-wind cumulus convection, including shallow cumulus and congestus with tops below the freezing level. We ran large-eddy simulations for an idealized case of trade-wind convection using different vertical shears in the zonal wind. Backward shear, whereby surface easterlies become upper westerlies, is effective at limiting vertical cloud development, which leads to a moister, shallower, and cloudier trade-wind layer. Without shear or with forward shear, shallow convection tends to deepen more, but clouds tops are still limited under forward shear. A number of mechanisms explain the observed behavior: First, shear leads to different surface wind speeds and, in turn, surface heat and moisture fluxes due to momentum transport, whereby the weakest surface wind speeds develop under backward shear. Second, a forward shear profile in the subcloud layer enhances moisture aggregation and leads to larger cloud clusters, but only on large domains that generally support cloud organization. Third, any absolute amount of shear across the cloud layer limits updraft speeds by enhancing the downward oriented pressure perturbation force. Backward shear-the most typical shear found in the winter trades-can thus be argued a key ingredient at setting the typical structure of the trade-wind layer. (©2020. The Authors.) |
| References: | Science. 1963 Aug 30;141(3583):767-78. (PMID: 17747539) Surv Geophys. 2017;38(6):1331-1353. (PMID: 29238118) Surv Geophys. 2017;38(6):1529-1568. (PMID: 31997845) J Adv Model Earth Syst. 2020 Dec;12(12):e2020MS002183. (PMID: 33381277) |
| فهرسة مساهمة: | Keywords: cumulus; large‐eddy simulation; shallow convection; trade wind; wind shear |
| تواريخ الأحداث: | Date Created: 20201231 Latest Revision: 20240330 |
| رمز التحديث: | 20240330 |
| مُعرف محوري في PubMed: | PMC7757185 |
| DOI: | 10.1029/2020MS002183 |
| PMID: | 33381277 |
| قاعدة البيانات: | MEDLINE |
Full Text Finder | تدمد: | 1942-2466 |
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| DOI: | 10.1029/2020MS002183 |