Optimized Alternate Mapping Correlated K‐Distribution Method for Atmospheric Longwave Radiative Transfer
Abstract Radiative transfer models are widely applied in climate models to simulate vertical temperature perturbations caused by external radiative forcings. A large part of radiative transfer models is the infrared gaseous spectral transmittance scheme, which quantifies the longwave atmospheric abs...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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American Geophysical Union (AGU)
2023-05-01
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| Series: | Journal of Advances in Modeling Earth Systems |
| Subjects: | |
| Online Access: | https://doi.org/10.1029/2022MS003419 |
| _version_ | 1827921714856591360 |
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| author | Yue Cai Feng Zhang Han Lin Jiangnan Li Hua Zhang Wenwen Li Shuai Hu |
| author_facet | Yue Cai Feng Zhang Han Lin Jiangnan Li Hua Zhang Wenwen Li Shuai Hu |
| author_sort | Yue Cai |
| collection | DOAJ |
| description | Abstract Radiative transfer models are widely applied in climate models to simulate vertical temperature perturbations caused by external radiative forcings. A large part of radiative transfer models is the infrared gaseous spectral transmittance scheme, which quantifies the longwave atmospheric absorption. A rapid infrared gaseous spectral transmittance scheme, called the Optimized alternate Mapping Correlated K‐Distribution model (OMCKD), is introduced in this paper. To improve the accuracy of our scheme without increasing pseudo‐monochromatic calculations, we introduce the optimal iteration method to automatically tune the equivalent absorption coefficients in the cumulative probability subspace. In addition, a new expression weighted by black‐body radiation is introduced to calculate the equivalent absorption coefficient. The OMCKD simulates heating rate and radiation flux with errors of less than 0.12 K d−1 and 0.35 W m−2, respectively, below stratopause for standard atmospheric profiles. The OMCKD is also evaluated and compared with the rapid radiative transfer model for general circulation models (RRTMG) in realistic atmospheric profiles. We found that OMCKD can accurately produce heating rates and generally captures radiative forcings associated with large perturbations to the concentrations of main greenhouse gases. Furthermore, the number of pseudo‐monochromatic calculations in OMCKD is 11.4% less than that in RRTMG, which indicates less computational cost. |
| first_indexed | 2024-03-13T04:31:25Z |
| format | Article |
| id | doaj.art-d96eae9aa1e8439a98891d9eb5bc46be |
| institution | Directory Open Access Journal |
| issn | 1942-2466 |
| language | English |
| last_indexed | 2024-03-13T04:31:25Z |
| publishDate | 2023-05-01 |
| publisher | American Geophysical Union (AGU) |
| record_format | Article |
| series | Journal of Advances in Modeling Earth Systems |
| spelling | doaj.art-d96eae9aa1e8439a98891d9eb5bc46be2023-06-19T13:40:46ZengAmerican Geophysical Union (AGU)Journal of Advances in Modeling Earth Systems1942-24662023-05-01155n/an/a10.1029/2022MS003419Optimized Alternate Mapping Correlated K‐Distribution Method for Atmospheric Longwave Radiative TransferYue Cai0Feng Zhang1Han Lin2Jiangnan Li3Hua Zhang4Wenwen Li5Shuai Hu6Department of Atmospheric and Oceanic Sciences and Institute of Atmospheric Sciences Fudan University Shanghai ChinaDepartment of Atmospheric and Oceanic Sciences and Institute of Atmospheric Sciences Fudan University Shanghai ChinaSchool of Atmospheric Science Nanjing University of Information Science and Technology Nanjing ChinaCanadian Centre for Climate Modelling and Analysis Science and Technology Branch Environment Canada Victoria BC CanadaState Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences Beijing ChinaSchool of Atmospheric Science Nanjing University of Information Science and Technology Nanjing ChinaNational University of Defense Technology Changsha ChinaAbstract Radiative transfer models are widely applied in climate models to simulate vertical temperature perturbations caused by external radiative forcings. A large part of radiative transfer models is the infrared gaseous spectral transmittance scheme, which quantifies the longwave atmospheric absorption. A rapid infrared gaseous spectral transmittance scheme, called the Optimized alternate Mapping Correlated K‐Distribution model (OMCKD), is introduced in this paper. To improve the accuracy of our scheme without increasing pseudo‐monochromatic calculations, we introduce the optimal iteration method to automatically tune the equivalent absorption coefficients in the cumulative probability subspace. In addition, a new expression weighted by black‐body radiation is introduced to calculate the equivalent absorption coefficient. The OMCKD simulates heating rate and radiation flux with errors of less than 0.12 K d−1 and 0.35 W m−2, respectively, below stratopause for standard atmospheric profiles. The OMCKD is also evaluated and compared with the rapid radiative transfer model for general circulation models (RRTMG) in realistic atmospheric profiles. We found that OMCKD can accurately produce heating rates and generally captures radiative forcings associated with large perturbations to the concentrations of main greenhouse gases. Furthermore, the number of pseudo‐monochromatic calculations in OMCKD is 11.4% less than that in RRTMG, which indicates less computational cost.https://doi.org/10.1029/2022MS003419correlated K‐distribution modelinfrared gaseous transmittance simulationoptimization method |
| spellingShingle | Yue Cai Feng Zhang Han Lin Jiangnan Li Hua Zhang Wenwen Li Shuai Hu Optimized Alternate Mapping Correlated K‐Distribution Method for Atmospheric Longwave Radiative Transfer Journal of Advances in Modeling Earth Systems correlated K‐distribution model infrared gaseous transmittance simulation optimization method |
| title | Optimized Alternate Mapping Correlated K‐Distribution Method for Atmospheric Longwave Radiative Transfer |
| title_full | Optimized Alternate Mapping Correlated K‐Distribution Method for Atmospheric Longwave Radiative Transfer |
| title_fullStr | Optimized Alternate Mapping Correlated K‐Distribution Method for Atmospheric Longwave Radiative Transfer |
| title_full_unstemmed | Optimized Alternate Mapping Correlated K‐Distribution Method for Atmospheric Longwave Radiative Transfer |
| title_short | Optimized Alternate Mapping Correlated K‐Distribution Method for Atmospheric Longwave Radiative Transfer |
| title_sort | optimized alternate mapping correlated k distribution method for atmospheric longwave radiative transfer |
| topic | correlated K‐distribution model infrared gaseous transmittance simulation optimization method |
| url | https://doi.org/10.1029/2022MS003419 |
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