Xiaomeng Jin: Observing distributions and chemistry of major air pollutants (O3 & PM2.5) from space

Observing the distributions and chemistry of major air pollutants (O3 and PM2.5) from space

Speaker: Xiaomeng Jin, University of California, Berkeley

Abstract:
Ambient exposure to fine particulate matter (PM2.5) and ground-level ozone (O3) is identified as a leading risk factor for global disease burden. A limitation to advancing our understanding of the cause and impacts of air pollution is the lack of observations with the spatial and temporal resolution needed to observe variability in emission, chemistry and population exposure. Satellite remote sensing fills a spatial gap in ground-based networks. I will first introduce how remotely sensed aerosol optical depth (AOD) products have been used to infer distributions of PM2.5. We use multiple satellite-based PM2.5 products to assess the PM2.5-related health benefits of emission reduction over New York State from 2002 to 2012. I will discuss different sources of uncertainties of satellite-derived PM2.5, and use multi-platform ground, airborne and radiosonde measurements to quantify different sources of uncertainties of the satellite-derived PM2.5. The second part will focus on ground-level O3. Urban O3 formation can be limited by NOx, VOCs, or both, complicating the design of effective O3 abatement plans. We use satellite observations of NO2 and HCHO to infer the O3 chemical regime. Two-decade multi-satellite HCHO/NO2 captures the timing and locations of the transition from VOC-limited to NOx-limited O3 production regime in major U.S. cities, which aligns with the observed long-term changes in urban-rural gradient of O3 and the reversal of O3 weekend effect. Our findings suggest promise for applying space-based observations to interpret the distribution and chemistry of PM2.5 and O3, particularly with the new-generation satellite instruments that offer finer spatial and temporal resolution.

Date: August 24, 2020