CCPP Scientific Documentation
v5.0.0
subroutine rrtmg_lw::rtrnmr ( real (kind=kind_phys), dimension(nbands), intent(in)  semiss,
real (kind=kind_phys), dimension(nlay), intent(in)  delp,
real (kind=kind_phys), dimension(0:nlp1), intent(in)  cldfrc,
real (kind=kind_phys), dimension(nbands,nlay), intent(in)  taucld,
real (kind=kind_phys), dimension(ngptlw,nlay), intent(in)  tautot,
real (kind=kind_phys), dimension(nbands,0:nlay), intent(in)  pklay,
real (kind=kind_phys), dimension(nbands,0:nlay), intent(in)  pklev,
real (kind=kind_phys), dimension(ngptlw,nlay), intent(in)  fracs,
real (kind=kind_phys), dimension(nbands), intent(in)  secdif,
integer, intent(in)  nlay,
integer, intent(in)  nlp1,
real (kind=kind_phys), dimension(0:nlay), intent(out)  totuflux,
real (kind=kind_phys), dimension(0:nlay), intent(out)  totdflux,
real (kind=kind_phys), dimension(nlay), intent(out)  htr,
real (kind=kind_phys), dimension(0:nlay), intent(out)  totuclfl,
real (kind=kind_phys), dimension(0:nlay), intent(out)  totdclfl,
real (kind=kind_phys), dimension(nlay), intent(out)  htrcl,
real (kind=kind_phys), dimension(nlay,nbands), intent(out)  htrb 
)
private
Parameters
semisslw surface emissivity
delplayer pressure thickness (mb)
cldfrclayer cloud fraction
taucldlayer cloud opt depth
tautottotal optical depth (gas+aerosols)
pklayintegrated planck func at lay temp
pklevintegrated planck func at lev temp
fracsplanck fractions
secdifsecant of diffusivity angle
nlaynumber of vertical layers
nlp1number of vertical levels (interfaces)
totufluxtotal sky upward flux ( \(w/m^2\))
totdfluxtotal sky downward flux ( \(w/m^2\))
htrtotal sky heating rate (k/sec or k/day)
totuclflclear sky upward flux ( \(w/m^2\))
totdclflclear sky downward flux ( \(w/m^2\))
htrclclear sky heating rate (k/sec or k/day)
htrbspectral band lw heating rate (k/day)

rtrnmr General Algorithm

  1. Setup maximum/random cloud overlap.
  2. Initialize for radiative transfer
  3. Downward radiative transfer loop:
    • cloudy layer
    • total sky radiance
    • clear sky radiance
  4. Compute spectral emissivity & reflectance, include the contribution of spectrally varying longwave emissivity and reflection from the surface to the upward radiative transfer.
  5. Compute total sky radiance.
  6. Compute clear sky radiance.
  7. Upward radiative transfer loop:
    • cloudy layer radiance
    • total sky radiance
    • clear sky radiance
  8. Process longwave output from band for total and clear streams. calculate upward, downward, and net flux.

References bpade, eps, exp_tbl, f_one, f_zero, fluxfac, heatfac, lhlw0, lhlwb, module_radlw_parameters::nbands, module_radlw_parameters::ngb, module_radlw_parameters::ngptlw, tau_tbl, tblint, tfn_tbl, and wtdiff.

Referenced by rrtmg_lw_run().