! radiation_homogeneous_sw.F90 - Shortwave homogeneous-column (no cloud fraction) solver ! ! (C) Copyright 2016- ECMWF. ! ! This software is licensed under the terms of the Apache Licence Version 2.0 ! which can be obtained at http://www.apache.org/licenses/LICENSE-2.0. ! ! In applying this licence, ECMWF does not waive the privileges and immunities ! granted to it by virtue of its status as an intergovernmental organisation ! nor does it submit to any jurisdiction. ! ! Author: Robin Hogan ! Email: r.j.hogan@ecmwf.int ! ! Modifications ! 2017-04-11 R. Hogan Receive albedos at g-points ! 2017-04-22 R. Hogan Store surface fluxes at all g points ! 2017-10-23 R. Hogan Renamed single-character variables ! 2019-01-14 R. Hogan Save spectral flux profile if required module radiation_homogeneous_sw public contains ! Provides elemental function "delta_eddington" #include "radiation_delta_eddington.h" !--------------------------------------------------------------------- ! Shortwave homogeneous solver, in which clouds are assumed to fill ! the gridbox horizontally subroutine solver_homogeneous_sw(nlev,istartcol,iendcol, & & config, single_level, cloud, & & od, ssa, g, od_cloud, ssa_cloud, g_cloud, & & albedo_direct, albedo_diffuse, incoming_sw, & & flux) use parkind1, only : jprb use yomhook, only : lhook, dr_hook, jphook use radiation_config, only : config_type use radiation_single_level, only : single_level_type use radiation_cloud, only : cloud_type use radiation_flux, only : flux_type, & & indexed_sum_profile, add_indexed_sum_profile use radiation_two_stream, only : calc_two_stream_gammas_sw, & & calc_reflectance_transmittance_sw use radiation_constants, only : Pi, GasConstantDryAir, & & AccelDueToGravity use radiation_adding_ica_sw, only : adding_ica_sw implicit none ! Inputs integer, intent(in) :: nlev ! number of model levels integer, intent(in) :: istartcol, iendcol ! range of columns to process type(config_type), intent(in) :: config type(single_level_type), intent(in) :: single_level type(cloud_type), intent(in) :: cloud ! Gas and aerosol optical depth, single-scattering albedo and ! asymmetry factor at each shortwave g-point real(jprb), intent(in), dimension(config%n_g_sw, nlev, istartcol:iendcol) :: & & od, ssa, g ! Cloud and precipitation optical depth, single-scattering albedo and ! asymmetry factor in each shortwave band real(jprb), intent(in), dimension(config%n_bands_sw,nlev,istartcol:iendcol) :: & & od_cloud, ssa_cloud, g_cloud ! Direct and diffuse surface albedos, and the incoming shortwave ! flux into a plane perpendicular to the incoming radiation at ! top-of-atmosphere in each of the shortwave g points real(jprb), intent(in), dimension(config%n_g_sw,istartcol:iendcol) :: & & albedo_direct, albedo_diffuse, incoming_sw ! Output type(flux_type), intent(inout):: flux ! Local variables ! Cosine of solar zenith angle real(jprb) :: cos_sza ! Diffuse reflectance and transmittance for each layer real(jprb), dimension(config%n_g_sw, nlev) :: reflectance, transmittance ! Fraction of direct beam scattered by a layer into the upwelling ! or downwelling diffuse streams real(jprb), dimension(config%n_g_sw, nlev) :: ref_dir, trans_dir_diff ! Transmittance for the direct beam in clear and all skies real(jprb), dimension(config%n_g_sw, nlev) :: trans_dir_dir ! Fluxes per g point real(jprb), dimension(config%n_g_sw, nlev+1) :: flux_up, flux_dn_diffuse, flux_dn_direct ! Combined gas+aerosol+cloud optical depth, single scattering ! albedo and asymmetry factor real(jprb), dimension(config%n_g_sw) :: od_total, ssa_total, g_total ! Two-stream coefficients real(jprb), dimension(config%n_g_sw) :: gamma1, gamma2, gamma3 ! Optical depth of cloud in g-point space real(jprb), dimension(config%n_g_sw) :: od_cloud_g ! Is there any cloud in the profile? logical :: is_cloudy_profile ! Number of g points integer :: ng ! Loop indices for level and column integer :: jlev, jcol real(jphook) :: hook_handle if (lhook) call dr_hook('radiation_homogeneous_sw:solver_homogeneous_sw',0,hook_handle) ng = config%n_g_sw ! Loop through columns do jcol = istartcol,iendcol ! Only perform calculation if sun above the horizon if (single_level%cos_sza(jcol) > 0.0_jprb) then cos_sza = single_level%cos_sza(jcol) ! Is there any cloud in the profile? is_cloudy_profile = .false. do jlev = 1,nlev if (cloud%fraction(jcol,jlev) >= config%cloud_fraction_threshold) then is_cloudy_profile = .true. exit end if end do ! If clear-sky fluxes need to be computed then we first ! compute the reflectance and transmittance of all layers, ! neglecting clouds. If clear-sky fluxes are not required then ! we only do the clear-sky layers since these will be needed ! when we come to do the total-sky fluxes. if (.not. config%do_sw_delta_scaling_with_gases) then ! Delta-Eddington scaling has already been performed to the ! aerosol part of od, ssa and g do jlev = 1,nlev if (config%do_clear .or. cloud%fraction(jcol,jlev) & & < config%cloud_fraction_threshold) then call calc_two_stream_gammas_sw(ng, cos_sza, & & ssa(:,jlev,jcol), g(:,jlev,jcol), & & gamma1, gamma2, gamma3) call calc_reflectance_transmittance_sw(ng, & & cos_sza, & & od(:,jlev,jcol), ssa(:,jlev,jcol), & & gamma1, gamma2, gamma3, & & reflectance(:,jlev), transmittance(:,jlev), & & ref_dir(:,jlev), trans_dir_diff(:,jlev), & & trans_dir_dir(:,jlev) ) end if end do else ! Apply delta-Eddington scaling to the aerosol-gas mixture do jlev = 1,nlev if (config%do_clear .or. cloud%fraction(jcol,jlev) & & < config%cloud_fraction_threshold) then od_total = od(:,jlev,jcol) ssa_total = ssa(:,jlev,jcol) g_total = g(:,jlev,jcol) call delta_eddington(od_total, ssa_total, g_total) call calc_two_stream_gammas_sw(ng, & & cos_sza, ssa_total, g_total, & & gamma1, gamma2, gamma3) call calc_reflectance_transmittance_sw(ng, & & cos_sza, od_total, ssa_total, & & gamma1, gamma2, gamma3, & & reflectance(:,jlev), transmittance(:,jlev), & & ref_dir(:,jlev), trans_dir_diff(:,jlev), & & trans_dir_dir(:,jlev) ) end if end do end if if (config%do_clear) then ! Use adding method to compute fluxes call adding_ica_sw(ng, nlev, incoming_sw(:,jcol), & & albedo_diffuse(:,jcol), albedo_direct(:,jcol), & & spread(cos_sza,1,ng), reflectance, transmittance, ref_dir, trans_dir_diff, & & trans_dir_dir, flux_up, flux_dn_diffuse, flux_dn_direct) ! Sum over g-points to compute and save clear-sky broadband ! fluxes flux%sw_up_clear(jcol,:) = sum(flux_up,1) if (allocated(flux%sw_dn_direct_clear)) then flux%sw_dn_direct_clear(jcol,:) & & = sum(flux_dn_direct,1) flux%sw_dn_clear(jcol,:) = sum(flux_dn_diffuse,1) & & + flux%sw_dn_direct_clear(jcol,:) else flux%sw_dn_clear(jcol,:) = sum(flux_dn_diffuse,1) & & + sum(flux_dn_direct,1) end if ! Store spectral downwelling fluxes at surface flux%sw_dn_diffuse_surf_clear_g(:,jcol) = flux_dn_diffuse(:,nlev+1) flux%sw_dn_direct_surf_clear_g(:,jcol) = flux_dn_direct(:,nlev+1) ! Save the spectral fluxes if required if (config%do_save_spectral_flux) then call indexed_sum_profile(flux_up, config%i_spec_from_reordered_g_sw, & & flux%sw_up_clear_band(:,jcol,:)) call indexed_sum_profile(flux_dn_direct, config%i_spec_from_reordered_g_sw, & & flux%sw_dn_clear_band(:,jcol,:)) if (allocated(flux%sw_dn_direct_clear_band)) then flux%sw_dn_direct_clear_band(:,jcol,:) & & = flux%sw_dn_clear_band(:,jcol,:) end if call add_indexed_sum_profile(flux_dn_diffuse, & & config%i_spec_from_reordered_g_sw, & & flux%sw_dn_clear_band(:,jcol,:)) end if end if ! Do clear-sky calculations ! Now the total-sky calculation. If this is a clear profile ! and clear-sky fluxes have been calculated then we can simply ! copy over the clear-sky fluxes, otherwise we need to compute ! fluxes now. if (is_cloudy_profile .or. .not. config%do_clear) then do jlev = 1,nlev ! Compute combined gas+aerosol+cloud optical properties; ! note that for clear layers, the reflectance and ! transmittance have already been calculated if (cloud%fraction(jcol,jlev) >= config%cloud_fraction_threshold) then od_cloud_g = od_cloud(config%i_band_from_reordered_g_sw,jlev,jcol) od_total = od(:,jlev,jcol) + od_cloud_g ssa_total = 0.0_jprb g_total = 0.0_jprb where (od_total > 0.0_jprb) ssa_total = (ssa(:,jlev,jcol)*od(:,jlev,jcol) & & + ssa_cloud(config%i_band_from_reordered_g_sw,jlev,jcol) & & * od_cloud_g) & & / od_total end where where (ssa_total > 0.0_jprb .and. od_total > 0.0_jprb) g_total = (g(:,jlev,jcol)*ssa(:,jlev,jcol)*od(:,jlev,jcol) & & + g_cloud(config%i_band_from_reordered_g_sw,jlev,jcol) & & * ssa_cloud(config%i_band_from_reordered_g_sw,jlev,jcol) & & * od_cloud_g) & & / (ssa_total*od_total) end where ! Apply delta-Eddington scaling to the cloud-aerosol-gas ! mixture if (config%do_sw_delta_scaling_with_gases) then call delta_eddington(od_total, ssa_total, g_total) end if ! Compute cloudy-sky reflectance, transmittance etc at ! each model level call calc_two_stream_gammas_sw(ng, & & cos_sza, ssa_total, g_total, & & gamma1, gamma2, gamma3) call calc_reflectance_transmittance_sw(ng, & & cos_sza, od_total, ssa_total, & & gamma1, gamma2, gamma3, & & reflectance(:,jlev), transmittance(:,jlev), & & ref_dir(:,jlev), trans_dir_diff(:,jlev), & & trans_dir_dir(:,jlev) ) end if end do ! Use adding method to compute fluxes for an overcast sky call adding_ica_sw(ng, nlev, incoming_sw(:,jcol), & & albedo_diffuse(:,jcol), albedo_direct(:,jcol), & & spread(cos_sza,1,ng), reflectance, transmittance, ref_dir, trans_dir_diff, & & trans_dir_dir, flux_up, flux_dn_diffuse, flux_dn_direct) ! Store overcast broadband fluxes flux%sw_up(jcol,:) = sum(flux_up,1) if (allocated(flux%sw_dn_direct)) then flux%sw_dn_direct(jcol,:) = sum(flux_dn_direct,1) flux%sw_dn(jcol,:) = sum(flux_dn_diffuse,1) & & + flux%sw_dn_direct(jcol,:) else flux%sw_dn(jcol,:) = sum(flux_dn_diffuse,1) & & + sum(flux_dn_direct,1) end if ! Likewise for surface spectral fluxes flux%sw_dn_diffuse_surf_g(:,jcol) = flux_dn_diffuse(:,nlev+1) flux%sw_dn_direct_surf_g(:,jcol) = flux_dn_direct(:,nlev+1) ! Save the spectral fluxes if required if (config%do_save_spectral_flux) then call indexed_sum_profile(flux_up, config%i_spec_from_reordered_g_sw, & & flux%sw_up_band(:,jcol,:)) call indexed_sum_profile(flux_dn_direct, config%i_spec_from_reordered_g_sw, & & flux%sw_dn_band(:,jcol,:)) if (allocated(flux%sw_dn_direct_band)) then flux%sw_dn_direct_band(:,jcol,:) & & = flux%sw_dn_band(:,jcol,:) end if call add_indexed_sum_profile(flux_dn_diffuse, & & config%i_spec_from_reordered_g_sw, & & flux%sw_dn_band(:,jcol,:)) end if else ! No cloud in profile and clear-sky fluxes already ! calculated: copy them over flux%sw_up(jcol,:) = flux%sw_up_clear(jcol,:) flux%sw_dn(jcol,:) = flux%sw_dn_clear(jcol,:) if (allocated(flux%sw_dn_direct)) then flux%sw_dn_direct(jcol,:) = flux%sw_dn_direct_clear(jcol,:) end if flux%sw_dn_diffuse_surf_g(:,jcol) = flux%sw_dn_diffuse_surf_clear_g(:,jcol) flux%sw_dn_direct_surf_g(:,jcol) = flux%sw_dn_direct_surf_clear_g(:,jcol) if (config%do_save_spectral_flux) then flux%sw_up_band(:,jcol,:) = flux%sw_up_clear_band(:,jcol,:) flux%sw_dn_band(:,jcol,:) = flux%sw_dn_clear_band(:,jcol,:) if (allocated(flux%sw_dn_direct_band)) then flux%sw_dn_direct_band(:,jcol,:) = flux%sw_dn_direct_clear_band(:,jcol,:) end if end if end if ! Cloud is present in profile else ! Set fluxes to zero if sun is below the horizon flux%sw_up(jcol,:) = 0.0_jprb flux%sw_dn(jcol,:) = 0.0_jprb if (allocated(flux%sw_dn_direct)) then flux%sw_dn_direct(jcol,:) = 0.0_jprb end if flux%sw_dn_diffuse_surf_g(:,jcol) = 0.0_jprb flux%sw_dn_direct_surf_g(:,jcol) = 0.0_jprb if (config%do_clear) then flux%sw_up_clear(jcol,:) = 0.0_jprb flux%sw_dn_clear(jcol,:) = 0.0_jprb if (allocated(flux%sw_dn_direct_clear)) then flux%sw_dn_direct_clear(jcol,:) = 0.0_jprb end if flux%sw_dn_diffuse_surf_clear_g(:,jcol) = 0.0_jprb flux%sw_dn_direct_surf_clear_g(:,jcol) = 0.0_jprb end if if (config%do_save_spectral_flux) then flux%sw_dn_band(:,jcol,:) = 0.0_jprb flux%sw_up_band(:,jcol,:) = 0.0_jprb if (allocated(flux%sw_dn_direct_band)) then flux%sw_dn_direct_band(:,jcol,:) = 0.0_jprb end if if (config%do_clear) then flux%sw_dn_clear_band(:,jcol,:) = 0.0_jprb flux%sw_up_clear_band(:,jcol,:) = 0.0_jprb if (allocated(flux%sw_dn_direct_clear_band)) then flux%sw_dn_direct_clear_band(:,jcol,:) = 0.0_jprb end if end if end if end if ! sun above horizon end do if (lhook) call dr_hook('radiation_homogeneous_sw:solver_homogeneous_sw',1,hook_handle) end subroutine solver_homogeneous_sw end module radiation_homogeneous_sw