source: trunk/LMDZ.GENERIC/libf/phystd/interpolateH2He.F90 @ 1145

Last change on this file since 1145 was 878, checked in by jleconte, 12 years ago

12/02/2013 == JL

  • Follows previous commit by Aymeric about bilinear interpolations:
    • Extended to all existing continua
    • generalized bilinearbig to work for various size inputs
  • because N2 and H2O continua databases are smaller, improvement around 15% for

an earth case.

File size: 4.2 KB
Line 
1     subroutine interpolateH2He(wn,temp,presH2,presHe,abcoef,firstcall,ind)
2
3!==================================================================
4!     
5!     Purpose
6!     -------
7!     Calculates the H2-He CIA opacity, using a lookup table from
8!     HITRAN (2011)
9!
10!     Authors
11!     -------
12!     R. Wordsworth (2011)
13!     
14!==================================================================
15
16      use datafile_mod, only: datadir
17
18      implicit none
19
20      ! input
21      double precision wn                 ! wavenumber             (cm^-1)
22      double precision temp               ! temperature            (Kelvin)
23      double precision presH2             ! H2 partial pressure    (Pascals)
24      double precision presHe             ! He partial pressure    (Pascals)
25
26      ! output
27      double precision abcoef             ! absorption coefficient (m^-1)
28
29      integer nS,nT
30      parameter(nS=2428)
31      parameter(nT=10)
32
33      double precision, parameter :: losch = 2.6867774e19
34      ! Loschmit's number (molecule cm^-3 at STP)
35      ! converts cm^5 molecule^-2 --> cm^-1 amagat^-2
36      ! see Richard et al. 2011, JQSRT for details
37
38      double precision amagatH2
39      double precision amagatHe
40      double precision wn_arr(nS)
41      double precision temp_arr(nT)
42      double precision abs_arr(nS,nT)
43
44      integer k,iT
45      logical firstcall
46
47      save wn_arr, temp_arr, abs_arr
48
49      character*100 dt_file
50      integer strlen,ios
51
52      character(LEN=*), parameter :: fmat1 = "(A20,F10.3,F10.3,I7,F7.1,E10.3,F5.3)"
53
54      character*20 bleh
55      double precision blah, Ttemp
56      integer nres
57
58      integer ind
59 
60      if(temp.gt.400)then
61         print*,'Your temperatures are too high for this H2-He CIA dataset.'
62         print*,'Please run mixed H2-He atmospheres below T = 400 K.'     
63         stop
64      endif
65
66      amagatH2 = (273.15/temp)*(presH2/101325.0)
67      amagatHe = (273.15/temp)*(presHe/101325.0)
68
69      if(firstcall)then ! called by sugas_corrk only
70         print*,'----------------------------------------------------'
71         print*,'Initialising H2-He continuum from HITRAN database...'
72
73!     1.1 Open the ASCII files
74         dt_file=TRIM(datadir)//'/continuum_data/H2-He_norm_2011.cia'
75
76         open(33,file=dt_file,form='formatted',status='old',iostat=ios)
77         if (ios.ne.0) then        ! file not found
78           write(*,*) 'Error from interpolateH2He'
79           write(*,*) 'Data file ',trim(dt_file),' not found.'
80           write(*,*) 'Check that your path to datagcm:',trim(datadir)
81           write(*,*) 'is correct. You can change it in callphys.def with:'
82           write(*,*) 'datadir = /absolute/path/to/datagcm'
83           write(*,*) 'Also check that the continuum data continuum_data/H2-He_norm_2011.cia is there.'
84           call abort
85         else
86
87            do iT=1,nT
88
89               read(33,fmat1) bleh,blah,blah,nres,Ttemp
90               if(nS.ne.nres)then
91                  print*,'Resolution given in file: ',trim(dt_file)
92                  print*,'is ',nres,', which does not match nS.'
93                  print*,'Please adjust nS value in interpolateH2He.F90'
94                  stop
95               endif
96               temp_arr(iT)=Ttemp
97
98               do k=1,nS
99                  read(33,*) wn_arr(k),abs_arr(k,it)
100               end do
101
102            end do
103     
104         endif
105         close(33)
106
107         print*,'interpolateH2He: At wavenumber ',wn,' cm^-1'
108         print*,'   temperature                 ',temp,' K'
109         print*,'   H2 partial pressure         ',presH2,' Pa'
110         print*,'   and He partial pressure     ',presHe,' Pa'
111
112      endif
113
114         call bilinearbig(nS,nT,wn_arr,temp_arr,abs_arr,wn,temp,abcoef,ind)
115
116         !print*,'the absorption is ',abcoef,' cm^5 molecule^-2'
117         !print*,'or ',abcoef*losch**2,' cm^-1 amagat^-2'
118
119         abcoef=abcoef*losch**2*100.0*amagatH2*amagatHe ! convert to m^-1
120
121         !print*,'We have ',amagatH2,' amagats of H2'
122         !print*,'and     ',amagatHe,' amagats of He'
123         !print*,'So the absorption is ',abcoef,' m^-1'
124
125         ! unlike for Rayleigh scattering, we do not currently weight by the BB function
126         ! however our bands are normally thin, so this is no big deal.
127
128      return
129    end subroutine interpolateH2He
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