Sensitivity of liquid clouds to homogenous freezing parameterizations

Herbert, R., Murray, B. J., Dobbie, S. J. and Koop, T. (2015) Sensitivity of liquid clouds to homogenous freezing parameterizations. Geophysical Research Letters, 42 (5). pp. 1599-1605. ISSN 0094-8276 doi: 10.1002/2014GL062729

Abstract/Summary

Water droplets in some clouds can supercool to temperatures where homogeneous ice nucleation becomes the dominant freezing mechanism. In many cloud resolving and mesoscale models, it is assumed that homogeneous ice nucleation in water droplets only occurs below some threshold temperature typically set at −40°C. However, laboratory measurements show that there is a finite rate of nucleation at warmer temperatures. In this study we use a parcel model with detailed microphysics to show that cloud properties can be sensitive to homogeneous ice nucleation as warm as −30°C. Thus, homogeneous ice nucleation may be more important for cloud development, precipitation rates, and key cloud radiative parameters than is often assumed. Furthermore, we show that cloud development is particularly sensitive to the temperature dependence of the nucleation rate. In order to better constrain the parameterization of homogeneous ice nucleation laboratory measurements are needed at both high (>−35°C) and low (<−38°C) temperatures.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/81674
Identification Number/DOI	10.1002/2014GL062729
Refereed	Yes
Divisions	No Reading authors. Back catalogue items Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	American Geophysical Union
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