| 项目编号: | 1725190
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| 项目名称: | Quantifying Entrainment and its Effects in Isolated, Sheared Cumuli and Thunderstorms |
| 作者: | Sonia Lasher-Trapp
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| 承担单位: | University of Illinois at Urbana-Champaign
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| 批准年: | 2017
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| 开始日期: | 2017-09-01
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| 结束日期: | 2020-08-31
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| 资助金额: | 218390
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| 资助来源: | US-NSF
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| 项目类别: | Continuing grant
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| 国家: | US
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| 语种: | 英语
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| 特色学科分类: | Geosciences - Atmospheric and Geospace Sciences
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| 英文关键词: | entrainment
; wind shear
; dilution
; cumulus entrainment
; storm
; non-sheared case
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| 英文摘要: | Earth's precipitation is primarily produced by deep cumulus clouds. Many aspects of cumulus convection are affected by entrainment, the process by which turbulent clouds introduce dry air from outside the cloud. Entrainment results in the dilution of the cloud which decreases the updraft speed and cloud height, and potentially prevents precipitation formation. This award will provide funding for the systematic investigation of entrainment in storms that occur in regions with environmental wind shear, the conditions that can sustain supercell thunderstorms. The researcher plans to develop general relationships between wind shear, cumulus entrainment, and convective precipitation which can be used to improve prediction of thunderstorm initiation, and rain, hail and lightning that form within these storms. In addition, the project will contribute to the development of two early-career researchers who will be trained in atmospheric science and high performance computing.
Prior research on cumulus entrainment has largely not taken wind shear into consideration. This project will use the CM1 cloud model to address three main hypotheses: 1) Unidirectional vertical wind shear enhances entrainment (compared to the non-sheared case) into a cloud updraft in its thermal-like stage, but directional vertical wind shear decreases this enhancement, 2) In environments with sufficiently strong vertical wind shear to generate a rotating updraft, the thermal-like initial updraft transforms into a jet-like updraft, decreasing the entrainment into, and dilution of, the rotating updraft, 3) The increased entrainment and dilution into a cloud updraft in its thermal stage, and the decreased entrainment and dilution of the jet stage results in non-negligible (>10%) decreases and increases (respectively) in precipitation production within the storm. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/89200
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| Appears in Collections: | 全球变化的国际研究计划
科学计划与规划
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| Recommended Citation: | |
Sonia Lasher-Trapp. Quantifying Entrainment and its Effects in Isolated, Sheared Cumuli and Thunderstorms. 2017-01-01.
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