| 1 | This directory contains the main part of the radiation scheme except |
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| 2 | for the calculation of gas optics. It is compiled into static library |
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| 3 | ../lib/libradiation.a and module files ../mod/radiation_*.mod. The |
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| 4 | coding conventions are described in the CONVENTIONS file. See the |
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| 5 | file ../driver/radiation_driver.f90 for an example of how the |
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| 6 | radiation scheme is called. The code is arranged as follows. |
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| 7 | |
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| 8 | The configuration information for the radiation scheme is stored in a |
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| 9 | "config" object (type defined in *radiation_config.f90*). After this |
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| 10 | has been populated depending on how the radiation scheme is to be |
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| 11 | configured, the subroutine "setup_radiation" in |
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| 12 | *radiation_interface.f90* is called. This sets up the gas, cloud and |
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| 13 | aerosol optics, all of which involve reading data from NetCDF files. |
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| 14 | The cloud and aerosol optics data are described in |
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| 15 | *radiation_aerosol_optics_data.f90* and |
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| 16 | *radiation_cloud_optics_data.f90*. |
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| 17 | |
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| 18 | The main interface to the radiation scheme is via the "radiation" |
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| 19 | subroutine in radiation_interface.f90, which takes six objects as |
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| 20 | input (noting that multiple columns are processed at once): |
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| 21 | |
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| 22 | single_level - all single-level fields such as skin temperature and |
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| 23 | surface albedo (type defined in *radiation_single_level.f90*) |
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| 24 | |
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| 25 | thermodynamics - pressure and temperature (type defined in |
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| 26 | *radiation_thermodynamics.f90*) |
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| 27 | |
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| 28 | gas - mixing ratios of gases (type defined in *radiation_gas.f90*) |
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| 29 | |
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| 30 | cloud - cloud fraction, water content and other information (type |
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| 31 | defined in *radiation_cloud.f90*) |
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| 32 | |
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| 33 | aerosol - mixing ratios of different aerosol species (type defined |
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| 34 | in *radiation_aerosol.f90*) |
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| 35 | |
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| 36 | The output is stored in the following object: |
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| 37 | |
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| 38 | flux - upwelling and downwelling shortwave and longwave fluxes (type |
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| 39 | defined in *radiation_flux.f90*) |
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| 40 | |
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| 41 | The "radiation" subroutine first computes the gas optical properties |
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| 42 | (in the form of 3D arrays of dimension column, height and spectral |
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| 43 | g-point), via a call to the "gas_optics" subroutine in |
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| 44 | *radiation_ifsrrtm.f90*, which provides an interface to the IFS |
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| 45 | implementation of the RRTM-G gas optics model in the ../ifsrrtm |
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| 46 | directory. For testing, a simple monochromatic gas model is also |
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| 47 | provided in *radiation_monochromatic.f90*. |
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| 48 | |
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| 49 | To these fields are added the contribution from aerosols via a call to |
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| 50 | the "aerosol_optics" subroutine, from *radiation_aerosol_optics.f90*. |
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| 51 | |
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| 52 | Cloud optical properties are computed (in the form of 3D arrays of |
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| 53 | dimension column, height and spectral band), via a call to the |
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| 54 | "cloud_optics" subroutine in *radiation_cloud_optics.f90*. |
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| 55 | |
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| 56 | The optical properties may then be saved to an intermediate NetCDF |
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| 57 | file via a routine in *radiation_save.f90*. |
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| 58 | |
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| 59 | Finally, the optics data are passed to the solver, which computes the |
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| 60 | flux profiles. Currently McICA nad SPARTACUS solvers are |
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| 61 | available. In the case of SPARTACUS, the longwave and shortwave |
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| 62 | versions are in *radiation_spartacus_lw.f90* and |
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| 63 | *radiation_spartacus_sw.f90*, respectively. These make use of |
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| 64 | routines in the following files: |
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| 65 | |
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| 66 | *radiation_two_stream.f90* - compute two-stream coefficients |
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| 67 | |
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| 68 | *radiation_matrix.f90* - matrix operations needed by SPARTACUS |
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| 69 | |
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| 70 | *radiation_overlap.f90* - compute cloud overlap matrices. |
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| 71 | |
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| 72 | Physical constants are provided in *radiation_constants.f90*. |
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