source: LMDZ6/trunk/libf/phylmd/ecrad/radiation/radiation_ice_optics_baran2016.F90 @ 5327

Last change on this file since 5327 was 4773, checked in by idelkadi, 11 months ago
  • Update of Ecrad in LMDZ The same organization of the Ecrad offline version is retained in order to facilitate the updating of Ecrad in LMDZ and the comparison between online and offline results. version 1.6.1 of Ecrad (https://github.com/lguez/ecrad.git)
  • Implementation of the double call of Ecrad in LMDZ


File size: 2.3 KB
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1! radiation_ice_optics_baran2016.F90 - Baran et al. (2016) scheme for ice optical properties
2!
3! (C) Copyright 2016- ECMWF.
4!
5! This software is licensed under the terms of the Apache Licence Version 2.0
6! which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
7!
8! In applying this licence, ECMWF does not waive the privileges and immunities
9! granted to it by virtue of its status as an intergovernmental organisation
10! nor does it submit to any jurisdiction.
11!
12! Author:  Robin Hogan
13! Email:   r.j.hogan@ecmwf.int
14!
15
16module radiation_ice_optics_baran2016
17
18  implicit none
19
20  ! The number of ice coefficients depends on the parameterization
21  integer, parameter :: NIceOpticsCoeffsBaran2016 = 5
22
23contains
24
25 
26  !---------------------------------------------------------------------
27  ! Compute ice-particle scattering properties using a
28  ! parameterization as a function of ice water mixing ratio and
29  ! temperature
30  subroutine calc_ice_optics_baran2016(nb, coeff, ice_wp, &
31       &  qi, temperature, od, scat_od, g)
32
33    use parkind1, only : jprb
34    !use yomhook,  only : lhook, dr_hook, jphook
35
36    ! Number of bands
37    integer, intent(in)  :: nb
38    ! Coefficients read from a data file
39    real(jprb), intent(in) :: coeff(:,:)
40    ! Ice water path (kg m-2) and mixing ratio (kg kg-1)
41    real(jprb), intent(in) :: ice_wp, qi
42    ! Temperature (K)
43    real(jprb), intent(in) :: temperature
44    ! Total optical depth, scattering optical depth and asymmetry factor
45    real(jprb), intent(out) :: od(nb), scat_od(nb), g(nb)
46   
47    ! Powers of temperature, some multiplied by qi
48    real(jprb) :: qi_T, T2, qi_over_T4
49   
50    !real(jphook) :: hook_handle
51
52    !if (lhook) call dr_hook('radiation_ice_optics:calc_ice_optics_baran2016',0,hook_handle)
53
54    T2 = temperature * temperature
55
56    if (qi < 1.0e-3_jprb) then
57      qi_T = qi * temperature
58      qi_over_T4 = 1.0_jprb / (T2 * T2)
59    else
60      qi_T = 1.0e-3_jprb * temperature
61      qi_over_T4 = 1.0_jprb / (T2 * T2)
62    end if
63
64    od      = ice_wp * coeff(1:nb,1) * qi_over_T4
65    scat_od = od * (coeff(1:nb,2) + coeff(1:nb,3) * qi_T)
66    g       = coeff(1:nb,4) + coeff(1:nb,5) * qi_T
67
68    !if (lhook) call dr_hook('radiation_ice_optics:calc_ice_optics_baran2016',1,hook_handle)
69
70  end subroutine calc_ice_optics_baran2016
71
72end module radiation_ice_optics_baran2016
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