PhD Defense by Aoxing Zhang
My name is Aoxing Zhang and I am an EAS Ph.D. student planning to graduate this year. My committee members are:
Dr. Yuhang Wang (advisor)
Dr. Greg Huey
Dr. Rodney Weber
Dr. Yi Deng
Dr. Nga Lee (Sally) Ng (External committee member from ChBE)
My defense will be at 12:00 pm, March 13, 2020. The location is in Ford ES&T Building, L1114.
Please let me know if further action needed. The defense title and abstract are shown below:
Defense topic: Understanding the global impacts of biomass burning aerosols and marine biogenic VOC
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 increases the atmospheric oxidation state and affects 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.