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UP: Fachverband Umweltphysik

UP 12: Atmosphäre - Labor

UP 12.2: Vortrag

Donnerstag, 20. März 2014, 10:00–10:15, MAG 100

Growth amplification of small ice particles in saturated sucrose and sodium silicate solutions — •Patricia Handmann¹ and Thomas Leisner² — ¹Karlsruher Institut für Technologie, Karlsruhe, Baden-Württemberg — ²Karlsruher Institut für Technologie, Karlsruhe, Baden-Württemberg

Reliable detection of particle phase state in clouds, containing water droplets and ice crystals, is a very challenging task. Furthermore the ability to discriminate between liquid and frozen cloud compounds is essential for understanding cloud glaciation and providing reliable parameterization for climate models. A vast number of optical instruments have been developed over the last decades to solve this task in field and laboratory experiments. In this presentation we revisit the old method of ice crystal growth amplification (Bigg 1956) and demonstrate its advantages and drawbacks in a more modern setup.

Within this approach we exploit the property of ice crystals to grow to easily detectable sizes in the supercooled aqueous solutions of sucrose and sodium silicate solutions. In contrast to this, liquid droplets dissipate upon contact with the surface of such solution. We will show video records of the laboratory experiments and will discuss the applicability of the method for phase detection of secondary particles emitted by droplets during freezing.

Cited References:

BIGG, E. K. A new Technique for Counting Ice-Forming Nuclei in Aerosols Tellus, Blackwell Publishing Ltd, 1957, 9, 394-400