Department of Climate and Space Sciences and Engineering in the College of Engineering at the University of Michigan

CLaSP Summer Seminar - Jialei Zhu

Date: August 2, 2018
Time: 3:30 pm - 4:30 pm
Location: CSRB Room 2424

Our guest for this week's CLaSP Special Seminar will be Jialei Zhu. Please join us! 

Title: " Mechanism of SOA formation determines radiative effect"

Abstract: Aerosols play a key role in determining the Earth’s radiation budget with the largest uncertainty in the current understanding of climate change. Secondary organic aerosol (SOA) often represents a major fraction of submicron-sized atmospheric organic aerosol and dominates ambient aerosol in tropical and remote regions, which plays a key role in climate change and air quality. However, significantly different treatments for formation of SOA in the model are expected to lead to different estimates of its radiative effect. Recent observations indicated SOA nearly always exists as an internal mixture with other aerosols based on the formation mechanism. The CESM/IMPACT model was developed to examine the influence of using an internal mixing state and to estimate the radiative forcing (RF) of SOA in the future. When compared with using an external mixture in previous studies, the radiative effect of SOA is decreased by a factor of >4 mainly due to the sharply reduced aerosol number. Our study indicated the future RF of SOA depends strongly on its mixing state and size distribution. The contribution of SOA to RF increases substantially (becomes more negative) in the future even though the increase of its burden is slight. Furthermore, the model was updated to include the SOA formed from organic nucleation based on the latest results of laboratory experiments. Organic nucleation enhances the baseline of particle number concentration in the preindustrial period (PI), which is significantly influenced by climate and land use change. Overall, we found a 15% reduced radiative forcing due to the increase in anthropogenic aerosol from PI to present day when including organic nucleation together with climate and land use change.

Upcoming Events

November 22nd
12:00 am - 11:59 pm
Thanksgiving - No Seminar
November 29th
3:30 pm - 5:00 pm
CLaSP Seminar Series - Dr. Valentin Pillet
December 6th
3:30 pm - 5:00 pm
CLaSP Seminar Series - Prof. Justin Kasper
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