Parameterizing microphysical effects on variances and covariances of moisture and heat content using a multivariate probability density function: a study with CLUBB (tag MVCS)
Microphysical processes, such as the formation, growth, and evaporation of precipitation, interact with variability and covariances (e.g., fluxes) in moisture and heat content. For instance, evaporation of rain may produce cold pools, which in turn may trigger fresh convection and precipitation....
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2016-11-01
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| Series: | Geoscientific Model Development |
| Online Access: | https://www.geosci-model-dev.net/9/4273/2016/gmd-9-4273-2016.pdf |
| _version_ | 1811225146804928512 |
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| author | B. M. Griffin V. E. Larson |
| author_facet | B. M. Griffin V. E. Larson |
| author_sort | B. M. Griffin |
| collection | DOAJ |
| description | Microphysical processes, such as the formation, growth, and evaporation of
precipitation, interact with variability and covariances (e.g., fluxes) in
moisture and heat content. For instance, evaporation of rain may produce cold
pools, which in turn may trigger fresh convection and precipitation. These
effects are usually omitted or else crudely parameterized at subgrid scales
in weather and climate models.<br><br>A more formal approach is pursued here, based on predictive, horizontally
averaged equations for the variances, covariances, and fluxes of moisture and
heat content. These higher-order moment equations contain microphysical
source terms. The microphysics terms can be integrated analytically, given a
suitably simple warm-rain microphysics scheme and an approximate assumption
about the multivariate distribution of cloud-related and
precipitation-related variables. Performing the integrations provides exact
expressions within an idealized context.<br><br>A large-eddy simulation (LES) of a shallow precipitating cumulus case is
performed here, and it indicates that the microphysical effects on
(co)variances and fluxes can be large. In some budgets and altitude ranges,
they are dominant terms. The analytic expressions for the integrals are
implemented in a single-column, higher-order closure model. Interactive
single-column simulations agree qualitatively with the LES. The analytic
integrations form a parameterization of microphysical effects in their own
right, and they also serve as benchmark solutions that can be compared to
non-analytic integration methods. |
| first_indexed | 2024-04-12T09:02:00Z |
| format | Article |
| id | doaj.art-d5a5bea9e734480f8cb9cd5de0137917 |
| institution | Directory Open Access Journal |
| issn | 1991-959X 1991-9603 |
| language | English |
| last_indexed | 2024-04-12T09:02:00Z |
| publishDate | 2016-11-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Geoscientific Model Development |
| spelling | doaj.art-d5a5bea9e734480f8cb9cd5de01379172022-12-22T03:39:13ZengCopernicus PublicationsGeoscientific Model Development1991-959X1991-96032016-11-0194273429510.5194/gmd-9-4273-2016Parameterizing microphysical effects on variances and covariances of moisture and heat content using a multivariate probability density function: a study with CLUBB (tag MVCS)B. M. Griffin0V. E. Larson1University of Wisconsin – Milwaukee, Department of Mathematical Sciences, Milwaukee, WI, USAUniversity of Wisconsin – Milwaukee, Department of Mathematical Sciences, Milwaukee, WI, USAMicrophysical processes, such as the formation, growth, and evaporation of precipitation, interact with variability and covariances (e.g., fluxes) in moisture and heat content. For instance, evaporation of rain may produce cold pools, which in turn may trigger fresh convection and precipitation. These effects are usually omitted or else crudely parameterized at subgrid scales in weather and climate models.<br><br>A more formal approach is pursued here, based on predictive, horizontally averaged equations for the variances, covariances, and fluxes of moisture and heat content. These higher-order moment equations contain microphysical source terms. The microphysics terms can be integrated analytically, given a suitably simple warm-rain microphysics scheme and an approximate assumption about the multivariate distribution of cloud-related and precipitation-related variables. Performing the integrations provides exact expressions within an idealized context.<br><br>A large-eddy simulation (LES) of a shallow precipitating cumulus case is performed here, and it indicates that the microphysical effects on (co)variances and fluxes can be large. In some budgets and altitude ranges, they are dominant terms. The analytic expressions for the integrals are implemented in a single-column, higher-order closure model. Interactive single-column simulations agree qualitatively with the LES. The analytic integrations form a parameterization of microphysical effects in their own right, and they also serve as benchmark solutions that can be compared to non-analytic integration methods.https://www.geosci-model-dev.net/9/4273/2016/gmd-9-4273-2016.pdf |
| spellingShingle | B. M. Griffin V. E. Larson Parameterizing microphysical effects on variances and covariances of moisture and heat content using a multivariate probability density function: a study with CLUBB (tag MVCS) Geoscientific Model Development |
| title | Parameterizing microphysical effects on variances and covariances of moisture and heat content using a multivariate probability density function: a study with CLUBB (tag MVCS) |
| title_full | Parameterizing microphysical effects on variances and covariances of moisture and heat content using a multivariate probability density function: a study with CLUBB (tag MVCS) |
| title_fullStr | Parameterizing microphysical effects on variances and covariances of moisture and heat content using a multivariate probability density function: a study with CLUBB (tag MVCS) |
| title_full_unstemmed | Parameterizing microphysical effects on variances and covariances of moisture and heat content using a multivariate probability density function: a study with CLUBB (tag MVCS) |
| title_short | Parameterizing microphysical effects on variances and covariances of moisture and heat content using a multivariate probability density function: a study with CLUBB (tag MVCS) |
| title_sort | parameterizing microphysical effects on variances and covariances of moisture and heat content using a multivariate probability density function a study with clubb tag mvcs |
| url | https://www.geosci-model-dev.net/9/4273/2016/gmd-9-4273-2016.pdf |
| work_keys_str_mv | AT bmgriffin parameterizingmicrophysicaleffectsonvariancesandcovariancesofmoistureandheatcontentusingamultivariateprobabilitydensityfunctionastudywithclubbtagmvcs AT velarson parameterizingmicrophysicaleffectsonvariancesandcovariancesofmoistureandheatcontentusingamultivariateprobabilitydensityfunctionastudywithclubbtagmvcs |