Colloquium: Dr. Jian Wang, Washington Univ. in St.Louis

ABSTRACT:

Marine clouds have a large spatial and temporal coverage and play an important role in the Earth’s climate system. Serving as cloud condensation nuclei (i.e., seeds upon which cloud droplets form), aerosol particles strongly influence the properties of marine clouds and consequently the global climate. New particle formation, namely the formation of aerosol particles from gas-phase molecules, is a major source of aerosol in the marine environment. In this talk, I will focus on new particle formation over mid-latitude oceans using recent airborne measurements and long-term surface observations. I will present the conditions that lead to the new particle formation, and the vertical distribution, frequency, and seasonal variation of the formation events. The potential mechanisms of new particle formation over the oceans and the influence of the particle formation on the population of cloud condensation nuclei will be discussed.