Parametrizations of Liquid and Ice Clouds’ Optical Properties in Operational Numerical Weather Prediction Models
Parametrization of radiation transfer through clouds is an important factor in the ability of Numerical Weather Prediction models to correctly describe the weather evolution. Here we present a practical parameterization of both liquid droplets and ice optical properties in the longwave and shortwave...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-01-01
|
| Series: | Atmosphere |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-4433/12/1/89 |
| _version_ | 1797414439611269120 |
|---|---|
| author | Harel. B. Muskatel Ulrich Blahak Pavel Khain Yoav Levi Qiang Fu |
| author_facet | Harel. B. Muskatel Ulrich Blahak Pavel Khain Yoav Levi Qiang Fu |
| author_sort | Harel. B. Muskatel |
| collection | DOAJ |
| description | Parametrization of radiation transfer through clouds is an important factor in the ability of Numerical Weather Prediction models to correctly describe the weather evolution. Here we present a practical parameterization of both liquid droplets and ice optical properties in the longwave and shortwave radiation. An advanced spectral averaging method is used to calculate the extinction coefficient, single scattering albedo, forward scattered fraction and asymmetry factor (β<sub>ext</sub>, ϖ, f, g), taking into account the nonlinear effects of light attenuation in the spectral averaging. An ensemble of particle size distributions was used for the ice optical properties calculations, which enables the effective size range to be extended up to 570 μm and thus be applicable for larger hydrometeor categories such as snow, graupel, and rain. The new parameterization was applied both in the COSMO limited-area model and in ICON global model and was evaluated by using the COSMO model to simulate stratiform ice and water clouds. Numerical weather prediction models usually determine the asymmetry factor as a function of effective size. For the first time in an operational numerical weather prediction (NWP) model, the asymmetry factor is parametrized as a function of aspect ratio. The method is generalized and is available on-line to be readily applied to any optical properties dataset and spectral intervals of a wide range of radiation transfer models and applications. |
| first_indexed | 2024-03-09T05:33:03Z |
| format | Article |
| id | doaj.art-399566736da44ad8ad03cbd5b9a9edcf |
| institution | Directory Open Access Journal |
| issn | 2073-4433 |
| language | English |
| last_indexed | 2024-03-09T05:33:03Z |
| publishDate | 2021-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Atmosphere |
| spelling | doaj.art-399566736da44ad8ad03cbd5b9a9edcf2023-12-03T12:31:04ZengMDPI AGAtmosphere2073-44332021-01-011218910.3390/atmos12010089Parametrizations of Liquid and Ice Clouds’ Optical Properties in Operational Numerical Weather Prediction ModelsHarel. B. Muskatel0Ulrich Blahak1Pavel Khain2Yoav Levi3Qiang Fu4The Israel Meteorological Service, Bet-Dagan 5025001, IsraelDeutscher Wetterdienst, 63067 Offenbach, GermanyThe Israel Meteorological Service, Bet-Dagan 5025001, IsraelThe Israel Meteorological Service, Bet-Dagan 5025001, IsraelDepartment of Atmospheric Sciences, University of Washington, Seattle, WA 98195, USAParametrization of radiation transfer through clouds is an important factor in the ability of Numerical Weather Prediction models to correctly describe the weather evolution. Here we present a practical parameterization of both liquid droplets and ice optical properties in the longwave and shortwave radiation. An advanced spectral averaging method is used to calculate the extinction coefficient, single scattering albedo, forward scattered fraction and asymmetry factor (β<sub>ext</sub>, ϖ, f, g), taking into account the nonlinear effects of light attenuation in the spectral averaging. An ensemble of particle size distributions was used for the ice optical properties calculations, which enables the effective size range to be extended up to 570 μm and thus be applicable for larger hydrometeor categories such as snow, graupel, and rain. The new parameterization was applied both in the COSMO limited-area model and in ICON global model and was evaluated by using the COSMO model to simulate stratiform ice and water clouds. Numerical weather prediction models usually determine the asymmetry factor as a function of effective size. For the first time in an operational numerical weather prediction (NWP) model, the asymmetry factor is parametrized as a function of aspect ratio. The method is generalized and is available on-line to be readily applied to any optical properties dataset and spectral intervals of a wide range of radiation transfer models and applications.https://www.mdpi.com/2073-4433/12/1/89cloudsoptical propertiesradiative transferice particleswater dropletsNWP |
| spellingShingle | Harel. B. Muskatel Ulrich Blahak Pavel Khain Yoav Levi Qiang Fu Parametrizations of Liquid and Ice Clouds’ Optical Properties in Operational Numerical Weather Prediction Models Atmosphere clouds optical properties radiative transfer ice particles water droplets NWP |
| title | Parametrizations of Liquid and Ice Clouds’ Optical Properties in Operational Numerical Weather Prediction Models |
| title_full | Parametrizations of Liquid and Ice Clouds’ Optical Properties in Operational Numerical Weather Prediction Models |
| title_fullStr | Parametrizations of Liquid and Ice Clouds’ Optical Properties in Operational Numerical Weather Prediction Models |
| title_full_unstemmed | Parametrizations of Liquid and Ice Clouds’ Optical Properties in Operational Numerical Weather Prediction Models |
| title_short | Parametrizations of Liquid and Ice Clouds’ Optical Properties in Operational Numerical Weather Prediction Models |
| title_sort | parametrizations of liquid and ice clouds optical properties in operational numerical weather prediction models |
| topic | clouds optical properties radiative transfer ice particles water droplets NWP |
| url | https://www.mdpi.com/2073-4433/12/1/89 |
| work_keys_str_mv | AT harelbmuskatel parametrizationsofliquidandicecloudsopticalpropertiesinoperationalnumericalweatherpredictionmodels AT ulrichblahak parametrizationsofliquidandicecloudsopticalpropertiesinoperationalnumericalweatherpredictionmodels AT pavelkhain parametrizationsofliquidandicecloudsopticalpropertiesinoperationalnumericalweatherpredictionmodels AT yoavlevi parametrizationsofliquidandicecloudsopticalpropertiesinoperationalnumericalweatherpredictionmodels AT qiangfu parametrizationsofliquidandicecloudsopticalpropertiesinoperationalnumericalweatherpredictionmodels |