New Sources and Mechanisms of CCN Production in the Remote Marine Environment

Presented on May 4, 2026, by

Prof. Jian Wang
Washington University in St. Louis

ABSTRACT

Marine low clouds strongly influence Earth’s radiative budget, and their properties are highly sensitive to the concentration of cloud condensation nuclei (CCN). Yet our understanding of CCN sources and budget in remote marine environments remains incomplete. In this talk, I will discuss results from field observations that reveal previously unrecognized sources and mechanisms of CCN production over remote oceans. Specific topics include (1) new particle formation in the upper part of the remote marine boundary layer following cold front passages, (2) new particle formation in the upper troposphere driven by stratospheric air intrusions, during which mixing of ozone-rich stratospheric air with moist tropospheric air enhances hydroxyl radical concentrations and promotes sulfuric acid formation and subsequent nucleation, and (3) the increasing boreal wildfire activity and long range transport of the wildfire aerosol plumes. The impact of these sources on marine boundary layer CCN population and cloud properties will also be discussed.

Please sign up on this online sheet if you are interested in meeting with him: https://docs.google.com/spreadsheets/d/1oQPqMCm-77udQoEkuFwPAJtqwvgAQn_YeQ-Q6oKiCzc/edit?gid=0#gid=0

BIO

Dr. Wang received his B.S. in physical chemistry from University of Science and Technology of China (USTC) in 1996 and his Ph.D. in chemical engineering from California Institute of Technology in 2003. He was a Goldhaber Distinguished Fellow at Brookhaven National Laboratory from 2002 to 2005 and received the Kenneth T. Whitby Award from American Association for Aerosol Research in 2013. He is currently the director of the Center for Aerosol Science and Engineering (CASE) and Professor of Energy, Environmental and Chemical Engineering at Washington University in St. Louis. His research focuses on aerosol instrumentation, the formation and evolution of atmospheric aerosol particles, and the effects of aerosols on clouds, climate, and air quality.