On the selection of prognostic moments in parametrization schemes for drop sedimentation

Ulrike Wacker; Christof Lüpkes

doi:10.1111/j.1600-0870.2009.00405.x

On the selection of prognostic moments in parametrization schemes for drop sedimentation

Tellus

Volume 61 (2009): Issue 4

By: Ulrike Wacker and Christof Lüpkes

Open Access

|Jan 2009

Abstract

Common parametrizationmodels for cloud microphysical processes use condensate mass density and/or particle number density as prognostic properties. However, other moments of the particle size distribution can likewise be chosen for prediction. This study deals with parametrization models with one and two, respectively, prognostic moments for the sedimentation of drop ensembles. The spectral resolving model defines the reference solution.

The evolution of the vertical profiles of liquid water content, drop number density and rain rate strongly depend on the choice of the prognostic moments in the parametrizationmodels. Inmodels with a single prognostic moment, its vertical profile is copied by all other moments. The moment of most physical pertinence is recommended for prediction. In models with two prognostic moments, the vertical profiles of all moments differ. The orders of the prognostic moments should be chosen close to the order of moments of highest relevance. Otherwise large errors occur. For example, comparison of modelled versus observed radar reflectivity (6th moment with respect to diameter) does not tell much about the quality of other properties if reflectivity is diagnosed from for example, number density and mass density. Furthermore, mass conservation is fulfilled only if mass density is forecasted.

References

Collins , W. D. , Rasch , P. J. , Boville , B. A. and co-authors. 2004. Description of the NCAR Community Atmosphere Model (CAM 3.0). NCAR Technical Note TN-464±STR, http://www.ccsm.ucar.edu/models/atm-cam .
Search in Google Scholar Back to article
Doms , G. , Förstner , J. , Heise , E. and co-authors 2003 . A De-scription of the Nonhydrostatic Regional Model IM. Con-sortium for Small Scale Modelling (COSMO), http://cosmo-model.cscs.ch/content/model/documentation/core/default.htm.
Search in Google Scholar Back to article
Geleyn , J.-E , Catry , B. , Bouteloup , Y. and Brozkova , R. 2008 . A statis-tical approach for sedimentation inside a microphysical precipitation scheme . Tellus 60A , 649 – 662 .
Search in Google Scholar Back to article
Ferrier , B. S. 1994 . A double-moment multiple-phase four-class bulk ice scheme: Part I: description. J. Atmos. Sc i . 51 , 249 – 280 .
Search in Google Scholar Back to article
Kessler , E. 1969 . On the Distribution and Continuity of Water Substance in Atmospheric Circulations . Amer. Meteor. Soc ., Boston .
Search in Google Scholar Back to article
Khain , A. , Pokrovsky , A. , Pinsky , M. , Seifert , A. and Phillips , V. 2004 . Simulations of effects of atmospheric aerosols on deep turbu-lent convective clouds by using a spectral microphysics mixed-phase cumulus cloud model. Part I: model description and possible applica-tions . J. Atmos. Sci . 61 , 2963 – 2982 .
Search in Google Scholar Back to article
Lüpkes , C. , Beheng , K. B. and Doms , G. 1989 . A parameterization scheme for simulating collision/coalescence of water drops . Beitr Phys. Atmos . 62 , 289 – 306 .
Search in Google Scholar Back to article
Lynn , B. and Khain , A. 2007 . Utilization of spectral bin microphysics and bulk parameterization schemes to simulate the cloud structure and precipitation in a mesoscale rain event . J. Geophys. Res . 112 , D22205 , 10.1029/2007JD008475 .
Open DOI Search in Google Scholar Back to article
Lynn , B. , Khain , A. , Dudhia , J. and co-authors 2005 . Spectral (bin) microphysics coupled with a mesoscale model (MM5). Part I: model description and first results . Mon. Wea. Rev . 133 , 44 - 58 .
Search in Google Scholar Back to article
Milbrandt , J. A. and Yau , M. K. 2005a . A multimoment bulk micro-physics parameterization. Part I: analysis of the role of the spectral shape parameter . J. Atmos. Sci . 62 , 3051 – 3064 .
Search in Google Scholar Back to article
Milbrandt , J.A. and Yau , M. K. 2005b . A multimoment bulk micro-physics parameterization. Part II: a proposed three-moment closure and scheme description . J. Atmos. Sci . 62 , 3065 – 3081 .
Search in Google Scholar Back to article
Roeckner , E. , Bäuml , G. , Bonaventura , L. and co-authors 2003 . The atmospheric general circulation model ECHAM5. Part. Max Planck Institute for Meteorology Report No. 349, http://www.mpimet.mpg.de/en/wissenschaft/modelle/echam/echam5.html#c2782.
Search in Google Scholar Back to article
Saito , K. , Fujita , T. , Yamada , Y. and co-authors 2006 . The operational JMA nonhydrostatic mesoscale model. Mon. Wea. Rev . 134 , 1266 - 1298 .
Search in Google Scholar Back to article
Seifert , A. and Beheng , K. D. 2005 . A two-moment cloud microphysics parameterization for mixed-phase clouds. Part I: model description . MeteoroL Atmos. Phys . 92 , 45 – 66 .
Search in Google Scholar Back to article
Tokay , A. , Kruger , A. and Krajewski , W. E 2001 . Comparison of drop size distribution measurements by impact and optical disdrometers . J. AppL Meteor . 40 , 2083 – 2097 .
Search in Google Scholar Back to article
Toro , E. F. 1999 . Riemann Solvers and Numerical Methods for Fluid Dynamics . Springer , Berlin .
Search in Google Scholar Back to article
Wacker , U. and Seifert , A. 2001 . Evolution of rain water profiles result-ing from pure sedimentation: spectral vs. parameterized description . Atmos. Res . 58 , 19 – 39 .
Search in Google Scholar Back to article
Waldvogel , A. 1974 . The No jump of raindrop spectra . J. Atmos. Sci . 31 , 1067 – 1078 .
Search in Google Scholar Back to article
Willis , P. 1984 . Functional fits to some observed drop size distributions and parameterization of rain . J.Atmos. Sci . 41 , 1648 – 1661 .
Search in Google Scholar Back to article

Articles in this issue

DOI: https://doi.org/10.1111/j.1600-0870.2009.00405.x | Journal eISSN: 3035-9554

Journal RSS Feed

Language: English

Page range: 498 - 511

Submitted on: Oct 24, 2008

Accepted on: Apr 24, 2009

Published on: Jan 1, 2009

Published by: Stockholm University Press

In partnership with: Paradigm Publishing Services

© 2009 Ulrike Wacker, Christof Lüpkes, published by Stockholm University Press
This work is licensed under the Creative Commons Attribution 4.0 License.

Volume 61 (2009): Issue 4