Satellite Detection of Effects of Absorbing Aerosols on Clouds over Urban Areas

卫星探测城市地区上空云吸收气溶胶的影响

• 批准号: 1139854
• 负责人: Mark Jacobson
• 金额: $ 21.89万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-02-01 至 2014-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1139854&HistoricalAwards=false
• 关键词: Satellite; Detection; Effects; Absorbing; Aerosols

This project will use satellite retrievals of aerosol optical depth versus cloud optical depth and cloud fraction to examine whether "boomerang" curves can be detected in three regions of the world that are sources of significant anthropogenic emissions from fossil fuels and/or solid biofuels. "Boomerang" refers to an increase followed by a decrease in cloud optical depth (COD) with increasing aerosol optical depth (AOD), which has been observed over Brazil where biomass burning is a dominant influence on atmospheric composition. The regions to be examined will include one urbanized region in China, one in India, and a third in Southern California. For each region, analyses of five years of satellite data will be carried out. The reason polluted urbanized regions will be targeted is because changes in COD and AOD should be more detectable than in non-urbanized regions. Nevertheless, the regions selected will be large enough to include rural as well as urban areas. As a result, differences between rural and urban areas can and will also be examined to determine whether microphysical or radiative effects dominate more in urban versus rural areas. Data from the Moderate Resolution Imaging Spectrometer (MODIS) instrument onboard the Aqua satellite with overpasses at approximately 1:30 PM local time will be used. This instrument provides relatively high spatial resolution (250 to 500 meters) data with near global coverage on a daily basis. MODIS Swath Level 2 aerosol, cloud, water vapor, and stability products will be employed.The results will provide input for future modeling studies to reduce one of the greatest uncertainties surrounding the effects of aerosols on climate, that of absorbing aerosols on cloudiness. This will ultimately advance understanding of the effects of absorbing aerosol (particularly black carbon) on climate because the cloud absorption effect has been ignored in all international assessments to date. A graduate student will be trained through participation in the project.

该项目将使用气溶胶光学深度与云光学深度和云部分的卫星检索，以检查在世界三个区域是否可以检测到“ Boomerang”曲线，这些曲线是从化石燃料和/或固体生物构造的大量人为排放的来源。 “ Boomerang”是指随着气溶胶光学深度（AOD）的增加而增加的增加，随后在巴西上观察到了气溶胶光学深度（AOD），在巴西，生物量燃烧是对大气组成的主要影响。要检查的地区将包括中国的一个城市化地区，一个在印度的城市化地区，在南加州的第三个地区。对于每个地区，将对五年的卫星数据进行分析。污染城市化区域的原因是，鳕鱼和AOD的变化应比非腐败区域更可检测到。然而，所选地区将足够大，以包括农村和城市地区。结果，农村地区和城市地区之间的差异可以并且还将进行检查，以确定在城市地区与农村地区的微物理或辐射效应是否占主导地位。来自中等分辨率成像光谱仪（MODIS）仪器的数据将使用当地时间约1:30 pm的立交桥的Aqua卫星上。该仪器每天提供相对较高的空间分辨率（250至500米）的数据，并提供几乎全球的覆盖范围。 MODIS Swath 2级气溶胶，云，水蒸气和稳定产品将用于未来建模研究的输入，以减少围绕气溶胶对气候影响的最大不确定性之一，即吸收气溶胶对云的影响。这最终将提高人们对吸收气溶胶（尤其是黑碳）对气候的影响的理解，因为迄今为止，所有国际评估中都忽略了云吸收效应。研究生将通过参与该项目进行培训。