Interpreting satelllite observations of tropospheric composition to improve understanding of climate and air quality

将综合利用卫星观测、飞机和地面测量以及全球大气成分三维模型，解决气候和空气质量方面的紧迫科学问题。 重点将放在对对流层（大气层最低12-17公里）臭氧、气溶胶及其前体的卫星观测的定量解释上。 对流层臭氧是一种主要的温室气体，是一种主要的污染物，并在很大程度上控制着其他污染物的分解。气溶胶降低健康和能见度，对气候的影响具有高度不确定性。对流层臭氧和气溶胶都可以在当地产生，也可以从远处输送。 臭氧和气溶胶前体包括燃烧排放的氮氧化物和二氧化硫等污染物。 具体任务包括：（1）通过与飞机和地面测量结果进行比较，评价和改进臭氧和气溶胶前体的卫星观测结果;（2）通过卫星观测结果的逆向建模，对臭氧和气溶胶前体的排放提供自上而下的限制;（3）评价和改进全球模型中气溶胶过程的表现。 实现这些目标将减少影响目前改善空气质量和应对气候变化努力的关键大气过程的不确定性。

Pressing scientific questions in climate and air quality will be addressed using a combination of satellite observations, aircraft and ground-based measurements, as well as a global three-dimensional model of atmospheric composition. Emphasis will be placed on quantitative interpretation of satellite observations of ozone, aerosols, and their precursors in the troposphere (lowest 12-17 km of the atmosphere). Tropospheric ozone is a major greenhouse gas, is a major pollutant, and largely controls the breakdown of other pollutants. Aerosols degrade health and visibility, and have a highly uncertain effect on climate. Both tropospheric ozone and aerosols can be produced locally and can be transported from afar. Ozone and aerosol precursors include pollutants such as nitrogen oxides and sulfur dioxide which are emitted from combustion. Specific tasks include 1) evaluate and improve satellite observations of ozone and aerosol precursors through comparison with aircraft and ground-based measurements, 2) provide top-down constraints on emissions of ozone and aerosol precursors through inverse modeling of satellite observations, and 3) evaluate and improve the representation of aerosol processes in global models. Achieving these objectives would reduce uncertainty in critical atmospheric processes that impair current efforts to improve air quality and respond to climate change.