Understanding the global impacts of biomass burning aerosols and marine biogenic VOC

By: 
Aoxing Zhang
Time: 
Friday, March 13, 2020 - 12:00pm
Place: 
ES&T L1114
Committee: 
Dr. Yuhang Wang (Advisor), Dr. Lewis G. Huey, Dr. Rodney J. Weber, Dr. Yi Deng, and Dr. Nga Lee (Sally) Ng
Summary: 

The transport of biomass burning aerosols and the oxidation state of the marine boundary layer (MBL) play significant roles in understanding the background climate condition of the remote regions. Biomass burning is provoked by natural factors or humans and has a profound impact on ecosystems, carbon cycles, climate change, and human society. Biomass burning is one major source of atmospheric aerosols, which is a potential medium in fire-climate interactions because of its role in the global radiative balance and cloud processing. The understanding of biomass burning emissions and its interaction with atmosphere and ecosystems is essential for estimating the climate impact due to biomass burning. On the other hand, the MBL volatile organic carbon (VOC) strongly impacts the MBL oxidation state. For example, glyoxal, a mid-product in biogenic organic carbon emission, can be photolyzed to produce HO2 radicals, which increase the atmospheric oxidation state and affect various oxidation processes such as ozone production.

This study focuses on the modeling approach of the effect of marine glyoxal on the MBL atmosphere oxidation state, and the impact of biomass burning on local weather and global radiative effect using the Community Earth System Model (CESM). We present an estimation of the direct radiative effect (DRE) of brown carbon (BrC), which can be emitted by biomass burning, and have potential stronger heating than black carbon (BC) over the region with strong deep convection e.g. remote tropics. We used the Region-Specific ecosystem feedback Fire (RESFire) model in CESM to study the impact of the African biomass burning aerosol on local and regional weather, and its feedback on the future biomass burning. In addition, we estimate the missing source of MBL glyoxal and discuss the impact of marine glyoxal to the MBL oxidation state