Jena 2013 – wissenschaftliches Programm

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UP: Fachverband Umweltphysik

UP 10: Atmosphäre - Spurengase, Aerosole und Labormessungen

UP 10.2: Vortrag

Mittwoch, 27. Februar 2013, 14:15–14:30, HS 5

A potential secondary ice process in tropospheric clouds — •Patricia Handmann, Thomas Pander, Alexei Kiselev, and Thomas Leisner — Karlsruher Institut für Technologie

Aerosols and water vapor are the two main constituents of clouds. At the same time, aerosols can nucleate ice in supercooled droplets and influence the precipitation processes in clouds via the WEGENER-BERGERON-FINDEISEN process of glaciation, when frozen droplets grow at the expense of liquid ones and fall to the ground. In experiments conducted at an electrodynamic trap with an attached high-speed camera, a potential secondary ice process influenced by aersols has been observed during the freezing of water droplets. Weak spots in the ice shell around a liquid core may crack up and bubbles may form which, once they break up, may eject small ice particles at several meters per second. This process may help in understanding the occasionally observed rapid glaciation in clouds.