Remote sensing of urban aerosol from space

该项目的目的是提高对城市气溶胶及其对化学天气和气候的影响的认识。这项工作计划使用来自地面分光光度计（AERONET）、激光雷达（EARLINET）和位于极轨卫星上的多种光学仪器（例如MERIS、AATSR、MODIS、SeaWiES、SCIAMACHY、GOME和POLDER）的数据进行。地球静止轨道上的光学仪器（例如，MSG上的SEVIRI）对于探测空气污染的时间趋势具有特别的价值。因此，从地球静止轨道上的辐射计反演城市气溶胶特征的能力也将被研究。城市气溶胶的卫星遥感需要了解下垫面光谱反射率A (λ) （λ为波长）。因此，将开发一种模拟确定城市地区空间测量下垫面反射率和光谱气溶胶光学厚度(AOT) τ的技术。AOT的信息和函数1n τ(λ)的测量斜率将用于确定全球主要城市地区的颗粒物柱浓度。这将使我们能够研究世界主要城市上空AOT和气溶胶负荷的时间趋势。计划使用SeaWiFS的数据（1997-2007），研究东京、墨西哥城、洛杉矶、北京和德里等主要城市的气溶胶负荷的长期统计数据。

The objective of the project is to improve the understanding of urban aersols and their influences on the chemical weather and climate. The work is planned to be performed using data from ground spectrophotometers (AERONET), lidars (EARLINET) and multiple optical instruments (e.g., MERIS, AATSR, MODIS, SeaWiES, SCIAMACHY, GOME, and POLDER) positioned on polar orbiting satellites. Optical instruments on geostationary orbits (e.g., SEVIRI on MSG) are of a particular value for the detection of temporal trends in air pollution. Therefore, the ability of retrieving urban aerosol characteristics from radiometers on geostationary orbits will be studies as well. Satellite remote sensing of urban aerosols requires knowledge of the underlying surface spectral reflectance A (λ) (λ is the wavelength). Therefore, a technique for the simulations determation of the underlying surface reflectance and the spectral aerosol optical thickness (AOT) τ from space measurements over urban areas will be developed. The information on AOT and the measured slope of the function 1n τ(λ) will be used to determine the column concentration of particulate matter over major urban areas worldwide. This will enable us to study temporal trends in AOT and aerosol load over major world cities. It is planned to use SeaWiFS data (1997-2007) for studies of the long term statistics of aerosol load in major cities including Tokyo, Mexico City, Los Angeles, Beijing, and Dehli.