Improved understanding of air quality and the carbon cycle using integrated space-based observations of atmospheric composition

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Human activity has produced dramatic changes in the composition of the atmosphere, with profound implications for climate and air quality. During the past two decades, space agencies around the world have invested in new satellite instruments to better measure these changes in atmospheric composition. The proposed research program will integrate this growing wealth of space-based atmospheric composition data, using novel chemical data assimilation techniques, to better assess the impact of human activity on air quality and climate. One aspect of the proposed work will focus on integrating observations from multiple satellites to obtain an improved description of tropospheric ozone. Tropospheric ozone is a powerful greenhouse gas and near the surface it is a major pollutant that is harmful to vegetation and animals. The distribution of tropospheric ozone is strongly influenced by chemical sinks and local emissions of precursor gases, and a key focus of the work will be to exploit the constraints on tropospheric ozone chemistry from the multiple satellite observations to better estimate ozone-induced damage to crops and vegetation, providing the first global observation-based estimate of ozone-induced vegetation damage. The proposed research program will also integrate observations of atmospheric CO2 from recently launched satellites to quantify regional sources and sinks of CO2, for which robust estimates are required for reliable projections of climate change. Another aspect of the work will be to combine space-based observations of solar-induced fluorescence (SIF) with atmospheric CO2 data to inform our understanding of the biospheric processes (gross primary productivity and respiration) driving the exchange of carbon between terrestrial ecosystems and the atmosphere, and of how changes in climate impact these processes. The proposed work will also examine the impact of pollution on the frequency of extreme precipitation events in Southeast Asia, a region with a large fraction of the global population and which is vulnerable to changes in water resources. The proposed research program is interdisciplinary and will provide students and postdoctoral fellows a unique training experience. There is increasing recognition that a more integrated and interdisciplinary approach is needed to address many of the environmental challenges that we face as a society. The research program will help ensure that the next generation of climate scientists in Canada possesses the diversity of knowledge required to address these challenges.