EXTERNAL SEMINAR CLOUDS UNDER THE MICROSCOPE: TOWARDS UNDERSTANDING ICE FORMATION IN THE ATMOSPHERE

SPEAKER: DR. ALEXEI KISELEV. KARLSRUHE INSTITUTE FOR TECHNOLOGY

2018.02.22 | Peter Schmidt Mikkelsen

Date Thu 15 Mar
Time 10:00 11:00
Location AUDITORIUM II, DEPARTMENT OF CHEMISTRY, AU

ABSTRACT

A traditional way to study clouds is to perform the aircraft-based measurements, or to create artificial clouds in a cloud tank. Quite often, however, such methods are not sufficient to reveal the underlying physical and chemical processes hidden at the microscopic level. Among such mysteries is the heterogeneous formation of ice in supercooled cloud droplets induced by the presence of aerosol particles. Typically, only one in ten thousand of aerosol particles would serve as a potential ice-nucleating particle (INP). Although it has been known for decades, that dust of various origins, bacteria, fungal spores and other biological particles, such as cellulose and diatom-infused sea spray, can raise the nucleation temperature, a molecular-scale picture of why materials of disparate chemical composition and structural order can have similar ice nucleation efficiency is lacking. This talk will review our recent efforts on characterization of ice nucleating properties of feldspar, a rock-forming mineral that has been recently identified as an important component of atmospheric mineral dust aerosol. I will demonstrate how a coherent combination of several modern laboratory methods and atomistic simulations can deliver new insights into the nature of heterogeneous nucleation of ice. The similarities and disparities of ice nucleation stimulated by organic and inorganic particles will be discussed.

For more information contact: Tina Santl-Temkiv temkiv@phys.au.dk

Arctic Research Centre