COLLEGE OF SCIENCES

SCHOOL OF EARTH AND ATMOSPHERIC SCIENCES

EAS Ph.D. Defense

Ruixiong Zhang

November 2, 2017

10:00 AM

Earth and Atmospheric Sciences

Ford Environmental Science & Technology (ES&T)

311 Ferst Drive, ES&TAtlanta, GA 30332-0340

Web: eas.gatech.edu

ES&T L1114

Title:Applications of satellite retrievals in deriving pollutant emissions and trends

Committee members: Dr. Yuhang Wang (Advisor), Dr. Greg Huey, Dr. Nga Lee Ng, Dr. Rodney Weber, Dr. JintaiLin (Peking University)

Abstract: This dissertation employs various satellite retrievals andthe 3-D Regional chEmicaltrAnsportModel (REAM) to(1) identify and quantify the emission sources, and (2) derive pollutant trends.

First, we use short-lived reactive aromatics as proxies to diagnose transport of pollutants through the Himalayas to Tibet. We find enhancements of reactive aromatics over Tibet by a factor of 6 on average due to rapid transport from India and nearby regions during the presence of a high-altitude cut-off low system.

Second, we derive anthropogenic NOx emissions with 4km spatial resolution using Ozone Monitoring Instrument (OMI) NO2retrieval in Yangtze River region during June-July-August (JJA) of 2005-2009 and 2010-2015. The NO2emission inversion using High-resolution Daily Retrieval-Inversion (HDRI) method proves powerful in quantifying the effects of urbanization.

Finally, we retrieve OMI tropospheric NO2VCDs and obtain the NO2relative trends over the United States. We improve the OMI retrievals for trend analysis by removing the ocean trend, using MODerate-resolution Imaging Spectroradiometer(MODIS)albedo data in air mass factors (AMFs) calculation, and applying lightning event filter to screen data. These improvements result in close agreement (within 0.8% yr-1) between EPA AQS in situ and OMI-based NO2annual relative trends.