Do clouds nucleate on glassy aerosols?

November 17, 2022

Markus Petters

Hosted by Sonia Kreidenweis

Abstract

The importance of amorphous glassy phase states has long been recognized by the scientific community. About a decade and a half ago, a suite of first studies showed that glassy phase states are common in atmospheric particles. These initial studies identified several important implications for the atmospheric sciences. First, slowing the rate of water condensation onto particles due to the presence of a glassy outer shell may increase the supersaturation required to activate such particles into cloud droplets. Second, glassy organic particles have been shown to promote heterogeneous ice nucleation under upper free tropospheric conditions. Third, glassy particles slow intraparticle mixing, thus kinetically limiting chemical reactions. These findings motivated a decade of intense research seeking to answer the newly emerged science questions of how glassy aerosols influence multiphase atmospheric chemistry as well as affecting the microphysics of warm and cold cloud formation. In this seminar I invite you to join me on a guided tour through this fascinating decade of discovery. I will show how technical challenges have been solved, which hypotheses have been confirmed, which have been called into question, and which open questions remain.