Contact freezing: a review of experimental studies

Autor: Luis A. Ladino Moreno, Ulrike Lohmann, Olaf Stetzer
Rok vydání: 2013
Předmět:
Zdroj: Atmospheric Chemistry and Physics, Vol 13, Iss 19, Pp 9745-9769 (2013)
Atmospheric Chemistry and Physics, 13 (19)
ISSN: 1680-7324
1680-7375
1680-7367
DOI: 10.5194/acp-13-9745-2013
Popis: This manuscript compiles both theoretical and experimental information on contact freezing with the aim to better understand this potentially important but still not well quantified heterogeneous freezing mode. There is no complete theory that describes contact freezing and how the energy barrier has to be overcome to nucleate an ice crystal by contact freezing. Experiments on contact freezing conducted using the cold plate technique indicate that it can initiate ice formation at warmer temperatures than immersion freezing. Additionally, a qualitative difference in the freezing temperatures between contact and immersion freezing has been found using different instrumentation and different ice nuclei. There is a lack of data on collision rates in most of the reported data, which inhibits a quantitative calculation of the freezing efficiencies. Thus, new or modified instrumentation to study contact nucleation in the laboratory and in the field are needed to identify the conditions at which contact nucleation could occur in the atmosphere. Important questions concerning contact freezing and its potential role for ice cloud formation and climate are also summarized.
Atmospheric Chemistry and Physics, 13 (19)
ISSN:1680-7375
ISSN:1680-7367
Databáze: OpenAIRE