Details

Autor(en) / Beteiligte

• Knopf, Daniel A
• Alpert, Peter A
• Wang, Bingbing

Titel

The Role of Organic Aerosol in Atmospheric Ice Nucleation: A Review

Ist Teil von

• ACS earth and space chemistry, 2018-03, Vol.2 (3), p.168-202

Ort / Verlag

United States: American Chemical Society

Erscheinungsjahr

2018

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Predicting the formation of ice in the atmosphere presents one of the great challenges in physical sciences with important implications for the chemistry and composition of the Earth’s atmosphere, the hydrological cycle, and climate. Among atmospheric ice formation processes, heterogeneous ice nucleation proceeds on aerosol particles ranging from a few nanometers to micrometers in size, commonly referred to as ice nucleating particles (INPs). Research over the last two decades has demonstrated that organic matter (OM) is ubiquitous in the atmosphere, present as organic aerosol (OA) particles or as coatings on other particle types. The physicochemical properties of OM make predicting how OM can contribute to the INP population challenging. This review focuses on the role of OM in INPs, summarizing and highlighting recent advances in our understanding of the ice nucleation process gained from theoretical, laboratory, and field studies. Examination of ice residuals and INPs with analytical techniques demonstrates that OM participates in atmospheric ice crystal formation. Molecular dynamic simulations provide insight into the microscopic processes that initiate ice nucleation. The amorphous phase state of OM in the supercooled and metastable regime is identified as a key factor in assessing the particles’ nucleation pathways and rates. A theoretical model is advanced, based on particle water activity, to holistically predict amorphous phase changes and ice nucleation rates of particles coated by OM. The goal of this review is to synthesize our current understanding and propose future research directions needed to fully evaluate how OA particles contribute to INPs in the atmosphere.