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Dr. Daniel Cohan
Associate Professor
Civil and Environmental Engineering
Rice University
6100 Main Street MS 519
Houston, TX 77005

Phone: 713-348-5129
Office: Keck Hall 116B
Email: cohan 'at' rice.edu

Improving Biogenic Emission Estimates Using Satellite Data

Vegetation is the leading source of volatile organic compounds (VOC) emissions, which can affect regional and urban air quality by contributing to ozone and particulate matter formation. Biogenic VOC emission estimates depend on temperature, vegetation conditions, and the amount of sunlight (specifically, photosynthetically active radiation (PAR)) reaching the ground.

Due to the frequent underestimation of clouds in meteorological models, PAR estimates in current biogenic emission models are largely uncertain. Our group, along with Dr. Arastoo Pour Biazar at the University of Alabama in Huntsville, is utilizing satellite-retrieved data to improve model estimates of both PAR, which affects BVOC emission estimates, and photolysis rates, which drive photochemistry in the troposphere. In this work, incoming solar radiation (insolation) is estimated based on cloud measurements from the Geostationary Operational Environmental Satellite (GOES). The calculation of insolation accounts for water vapor, total overhead ozone and aerosol optical depth. These updated satellite inputs are being implemented into biogenic emission models as well as air quality models in order to quantify their impact on simulations of ground-level ozone and PM concentrations and their sensitivities to emissions changes.

Funding: NASA Air Quality Applied Sciences Team and Texas Air Quality Research Program

Participants: Erin Chavez-Figueroa and Rui Zhang