| DOI: | 10.2172/1326749
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| 报告号: | BNL--112642-2016
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| 报告题名: | Atmospheric System Research Marine Low Clouds Workshop Report, January 27-29,2016 |
| 作者: | Jensen, M.; Wang, J.; Wood, R.
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| 出版年: | 2016
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| 发表日期: | 2016-06-01
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| 总页数: | 22
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| 国家: | 美国
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| 语种: | 英语
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| 中文主题词: | 气溶胶
; 大气辐射
; 反照率
; 大气加热
; 湍流/气流
; 云
; 降水
; 反射率
; 卷挟
; 湍流
; 激光雷达
; 雷达
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| 主题词: | AEROSOLS
; ATMOSPHERIC RADIATION
; ALBEDO
; ATMOSPHERIC HEATING
; TURBULENCE
; CLOUDS
; PRECIPITATION
; ENTRAINMENT
; LIDAR
; RADAR
|
| 英文摘要: | Marine low clouds are a major determinant of the Earth?s albedo and are a major source of uncertainty in how the climate responds to changing greenhouse gas levels and anthropogenic aerosol. Marine low clouds are particularly difficult to simulate accurately in climate models, and their remote locations present a significant observational challenge. A complex set of interacting controlling processes determine the coverage, condensate loading, and microphysical and radiative properties of marine low clouds. Marine low clouds are sensitive to atmospheric aerosol in several ways. Interactions at microphysical scales involve changes in the concentration of cloud droplets and precipitation, which induce cloud dynamical impacts including changes in entrainment and mesoscale organization. Marine low clouds are also impacted by atmospheric heating changes due to absorbing aerosols. The response of marine low clouds to aerosol perturbations depends strongly upon the unperturbed aerosol-cloud state, which necessitates greater understanding of processes controlling the budget of aerosol in the marine boundary layer. Entrainment and precipitation mediate the response of low clouds to aerosols but these processes also play leading roles in controlling the aerosol budget. The U.S. Department of Energy Atmospheric Radiation Measurement (ARM) Climate Research Facility and Atmospheric System Research (ASR) program are making major recent investments in observational data sets from fixed and mobile sites dominated by marine low clouds. This report provides specific action items for how these measurements can be used together with process modeling to make progress on understanding and quantifying the key cloud and aerosol controlling processes in the next 5-10 years. Measurements of aerosol composition and its variation with particle size are needed to advance a quantitative, process-level understanding of marine boundary-layer aerosol budget. Quantitative precipitation estimates that combine radar and lidar measurements are becoming available, and these could be used to test process models, quantify precipitation responses to aerosol, and constrain climate models. Models and observations can be used to constrain how clouds respond dynamically to changing precipitation. New measurements of turbulence from ground-based remote sensing could be used to attempt to relate entrainment to the vertical and horizontal structure of turbulence in the boundary layer. Cloud-top entrainment plays a major role in modulating how low clouds respond to both aerosols and to greenhouse gases, so investment in promising new observational estimates would be beneficial. Precipitation formation and radiative cooling both help marine low clouds to organize on the mesoscale. More work is needed to develop metrics to characterize mesoscale organization, to elucidate mechanisms that determine the type and spatial scale of mesoscale cellular convection, and to understand the role of mesoscale structures in the stratocumulus-to-cumulus transition. |
| URL: | http://www.osti.gov/scitech/servlets/purl/1326749
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| Citation statistics: |
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| 资源类型: | 研究报告
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/42102
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| Appears in Collections: | 过去全球变化的重建
影响、适应和脆弱性
科学计划与规划
气候变化与战略
全球变化的国际研究计划
气候减缓与适应
气候变化事实与影响
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| 1326749.pdf（779KB） | 研究报告 | -- | 开放获取 | | View
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| Recommended Citation: | |
Jensen, M.,Wang, J.,Wood, R.. Atmospheric System Research Marine Low Clouds Workshop Report, January 27-29,2016. 2016-01-01.
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