| 项目编号: | 1540954
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| 项目名称: | Ice Nucleation in Cirrus Clouds: Anthropogenic Climate Forcing and Uncertainties |
| 作者: | Joyce Penner
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| 承担单位: | University of Michigan Ann Arbor
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| 批准年: | 2014
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| 开始日期: | 2015-09-01
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| 结束日期: | 2018-08-31
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| 资助金额: | USD572578
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| 资助来源: | US-NSF
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| 项目类别: | Standard 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: | cirrus cloud
; research
; ice formation
; aerosol
; soa
; climate
; ice cloud nucleation
; climate model
; soa formation
; ice crystal
; global chemistry/climate model
; soa nucleation
; climate community
; significant climate
; climate modeler
|
| 英文摘要: | This research focuses on the use of a global chemistry/climate model to improve the modeling of ice formation in cirrus clouds. This research will better inform climate modelers about the causes of differences in model predictions of the effects of small particles (aerosol) in cirrus clouds. It will also provide a representation of aerosol and ice formation that is based on physical and chemical processes and broadly consistent with the field observations used to evaluate the model.
The researchers hypothesize that a substantial fraction of ice formation in cirrus clouds is associated with secondary organic aerosols (SOA) and/or solid ammonium sulfate (NH4)2SO4 and that changes in these aerosols over time result in a significant climate forcing. The hypothesis will be tested using the Community Atmosphere Model (CAM5) climate model coupled to the IMPACT aerosol model. The IMPACT model ties the formation of SOA to the photochemical oxidation of volatile organic compounds (VOCs) based on a recently extended oxidation scheme. The researchers are in the process of extending the SOA formation framework to allow it to consider how the formation mechanism alters the size distribution of both primary organics and other aerosol species associated with SOA. In this research, they will explore several ways of parameterizing SOA nucleation. They will compare the changes in SOA formation and forcing in cirrus clouds using varying amounts of dust, sulfate, glassy organic aerosols (depending on the glass transition temperature of each SOA), and solid (NH4)2SO4.
The model simulations will be compared with observations from recent measurement campaigns to identify which treatments of SOA formation, ice cloud nucleation, and updraft velocities are best able to reproduce the observations. This research will better inform the climate community of the causes of differences in model predictions of aerosol effects in cirrus clouds. The results of this research will aid in quantifying climate forcing by aerosols and help to inform policy makers of the possible role of aerosols in either heating or cooling climate through their action in nucleating ice crystals. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/93516
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| Appears in Collections: | 影响、适应和脆弱性
气候减缓与适应
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| Recommended Citation: | |
Joyce Penner. Ice Nucleation in Cirrus Clouds: Anthropogenic Climate Forcing and Uncertainties. 2014-01-01.
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