Title Parameterizing the competition between homogeneous and heterogeneous freezing in ice cloud formation; polydisperse ice nuclei
Author Barahona, D.; Nenes, A.
Author Affil Barahona, D., Georgia Institute of Technology, School of Chemical and Biomolecular Engineering, Atlanta, GA
Source Atmospheric Chemistry and Physics, 9(16), p.5933-5948, . Publisher: Copernicus, Katlenburg-Lindau, International. ISSN: 1680- 7316
Publication Date 2009
Notes In English. Includes appendices; published in Atmospheric Chemistry and Physics Discussions: 5 May 2009, http://www.atmos-chem-phys- discuss.net/9/10957/2009/acpd-9-10957- 2009.html ; accessed in April, 2011. 69 refs. GeoRef Acc. No: 310160
Index Terms aerosols; precipitation (meteorology); climate; clouds (meteorology); cooling; crystal growth; crystals; freezing; ice; ice crystals; nucleation; stratosphere; supersaturation; water vapor; atmospheric precipitation; black carbon; clouds; crystallization; equations; heterogeneity; homogeneity; size distribution
Abstract This study presents a comprehensive ice cloud formation parameterization that computes the ice crystal number, size distribution, and maximum supersaturation from precursor aerosol and ice nuclei. The parameterization provides an analytical solution of the cloud parcel model equations and accounts for the competition effects between homogeneous and heterogeneous freezing, and, between heterogeneous freezing in different modes. The diversity of heterogeneous nuclei is described through a nucleation spectrum function which is allowed to follow any form (i.e., derived from classical nucleation theory or from observations). The parameterization reproduces the predictions of a detailed numerical parcel model over a wide range of conditions, and several expressions for the nucleation spectrum. The average error in ice crystal number concentration was -2.08.5% for conditions of pure heterogeneous freezing, and, 4.721% when both homogeneous and heterogeneous freezing were active. The formulation presented is fast and free from requirements of numerical integration.
URL http://www.atmos-chem-phys.net/9/5933/2009/acp-9-5933-2009.pdf
Publication Type journal article
Record ID 65006693