项目编号: | 1441062
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项目名称: | Modeling Satellite Correlations of Aerosol Optical Depth Versus Cloud Optical Depth Over Megacities |
作者: | Mark Jacobson
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承担单位: | Stanford University
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批准年: | 2014
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开始日期: | 2015-03-01
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结束日期: | 2018-02-28
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资助金额: | USD460199
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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: | cloud
; aerosol
; cloud optical depth
; satellite measurement
; project
; satellite datum
; cod
; cloud absorption effect
; aerosol feedback
; aerosol optical depth
; satellite retrieval
; aerosol/cloud interaction
; effect
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英文摘要: | This project seeks to gain a better understanding of aerosol/cloud interactions and the effects of these on global temperatures. The research is based on investigating satellite measurements of the thickness of aerosols (small particles) and clouds in the atmosphere over several global megacities. Data from a prior study over 2 megacities suggest that as the thickness of aerosols increases in the atmosphere, the density of clouds tends also to increase to a point, but then begins to decrease. Since satellite data can show correlations but not cause and effect, and models can show cause/effect, a computer model will be used in this project to simulate the relationship between clouds and aerosols over three megacities. The results will help to improve the ability of computer models to predict global climate change.
This research focuses on the investigating satellite measurements of aerosol optical depth (AOD) and cloud optical depth (COD) over several megacities to assess the relative importance of different types of aerosol feedbacks on clouds. Previously a boomerang curve was identified (an increase then a decrease of COD with increasing AOD) where the increase in COD at low AOD is believed to be due to microphysical (indirect) effects and a decrease in COD at high AOD is thought to be due to radiative effects (cloud absorption effects and the semidirect effect).
The project consists of three tasks: 1) complete the satellite retrieval worked performed for the first part of the project over one more megacity region, New Delhi India; 2) use a nested global-through-local 3-D model (GATOR-GCMOM) to determine whether the boomerang curves found in the satellite data can be attributed to absorbing aerosols; and 3) run a 24-year global baseline simulation and sensitivity simulations examining the separate effects of fossil-fuel soot, solid biofuel soot and gases, biomass burning soot and gases, methane, and all anthropogenic components on global climate, accounting for indirect effects, semi-direct effect, and the cloud absorption effect. To evaluate the significance of the model results, a two-sided t-test for unequal sample sizes of unequal variance will be used to determine whether the computer modeled difference in a given parameter between a baseline simulation and a sensitivity simulation is statistically significant relative to chaotic variation in a climate model. |
资源类型: | 项目
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标识符: | http://119.78.100.158/handle/2HF3EXSE/95069
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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: |
Mark Jacobson. Modeling Satellite Correlations of Aerosol Optical Depth Versus Cloud Optical Depth Over Megacities. 2014-01-01.
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