Interpreting Satellite Observations of Atmospheric Composition to Understand Air Quality and Climate Processes

Pressing scientific questions in air quality and climate will be addressed using a combination of satellite observations, ground-based measurements, and a global three-dimensional model of atmospheric composition. Emphasis will be placed on quantitative interpretation of satellite observations of atmospheric particles, ozone, and their precursors in the troposphere (lowest 12-17 km of the atmosphere). Atmospheric particles degrade health and visibility, and have highly uncertain effects on climate. Tropospheric ozone is a major greenhouse gas, is a major pollutant, and largely controls the breakdown of other pollutants. Both tropospheric ozone and atmospheric particles can be produced locally and can be transported from afar. Precursors for atmospheric particles and tropospheric ozone include nitrogen oxides and sulfur dioxide which are emitted from combustion. Specific objectives of the research program include 1) evaluate and improve simulations of precursors of atmospheric particles and ozone through comparison with satellite and ground-based measurements, 2) enhance the representation of atmospheric particle processes in global models, and 3) develop improved satellite-based estimates of global ground-level fine particulate matter (PM2.5) for air quality and health applications. Achieving these objectives would reduce uncertainty in critical atmospheric processes that impair current efforts to improve air quality and respond to climate change.