source: trunk/LMDZ.GENERIC/libf/phystd/interpolateH2Ocont_PPC.F90 @ 1579

Last change on this file since 1579 was 716, checked in by rwordsworth, 12 years ago

Mainly updates to radiative transfer and gas management scheme.
Most CIA data now read from standard HITRAN datafiles. For the H2O
continuum, two options have been added: the standard CKD continuum,
and the empirical formula in PPC (Pierrehumbert 2010). Use the toggle
'H2Ocont_simple' in callphys.def to choose.

Note to Martians: I've changed the default values of 'sedimentation' and
'co2cond' in inifis to false. Both these are defined in the standard deftank
callphys.def file, so there shouldn't be any compatibility problems.

  • Property svn:executable set to *
File size: 2.9 KB
Line 
1     subroutine interpolateH2Ocont_PPC(wn,temp,presS,presF,abcoef,firstcall)
2
3!==================================================================
4!     
5!     Purpose
6!     -------
7!     Calculates the H2O continuum opacity, using the formulae
8!     provided in Pierrehumbert, PPC (2010). As this is based on
9!     the CKD continuum, it provides a useful check for the
10!     implementation of the more general interpolateH2Ocont_CKD.F90.
11!
12!     Authors
13!     -------
14!     R. Wordsworth (2012)
15!     
16!==================================================================
17
18      use watercommon_h, only: mH2O
19      use datafile_mod, only: datadir
20      implicit none
21
22      ! input
23      double precision wn                 ! wavenumber             (cm^-1)
24      double precision temp               ! temperature            (Kelvin)
25      double precision presS              ! self-pressure          (Pascals)
26      double precision presF              ! foreign (air) pressure (Pascals)
27
28      ! parameters
29      double precision, parameter :: T0 = 296.0
30      double precision, parameter :: p0 = 1.D+4
31
32      ! variables
33      double precision rho_w, x
34
35      ! output
36      double precision abcoef             ! absorption coefficient (m^-1)
37
38      logical firstcall
39
40      x = wn - 2500.
41
42      if(firstcall)then ! called by sugas_corrk only
43         print*,'----------------------------------------------------'
44         print*,'Testing H2O continuum...'
45
46         print*,'interpolateH2Ocont: At wavenumber ',wn,' cm^-1'
47         print*,'   temperature ',temp,' K'
48         print*,'   H2O pressure ',presS,' Pa'
49
50         rho_w = presS/((8.31446/(mH2O/1000.))*temp)
51
52         if(wn.gt.500 .and. wn.lt.1400)then
53            abcoef = exp(12.167 - 0.050898*wn + 8.3207e-5*wn**2 - 7.0748e-8*wn**3 + 2.3261e-11*wn**4)*(T0/temp)**4.25*(presS/p0)
54         elseif(wn.gt.2100 .and. wn.lt.3000)then
55            abcoef = exp(-6.0055 - 0.0021363*x + 6.4723e-7*x**2 - 1.493e-8*x**3 + 2.5621e-11*x**4 + 7.328e-14*x**5)*(T0/temp)**4.25*(presS/p0)
56         else
57            abcoef = 0.0
58         endif
59         abcoef = abcoef*rho_w
60
61         print*,'The self absorption is ',abcoef,' m^-1'
62         print*,'And optical depth / km : ',1000.0*abcoef
63
64      else
65
66         rho_w = presS/((8.31446/(mH2O/1000.))*temp)
67
68         if(wn.gt.500 .and. wn.lt.1400)then
69            abcoef = exp(12.167 - 0.050898*wn + 8.3207e-5*wn**2 - 7.0748e-8*wn**3 + 2.3261e-11*wn**4)*(T0/temp)**4.25*(presS/p0)
70         elseif(wn.gt.2100 .and. wn.lt.3000)then
71            abcoef = exp(-6.0055 - 0.0021363*x + 6.4723e-7*x**2 - 1.493e-8*x**3 + 2.5621e-11*x**4 + 7.328e-14*x**5)*(T0/temp)**4.25*(presS/p0)
72         else
73            abcoef = 0.0
74         endif
75         abcoef = abcoef*rho_w
76
77         ! unlike for Rayleigh scattering, we do not currently weight by the BB function
78         ! however our bands are normally thin, so this is no big deal.
79
80      endif
81
82      return
83    end subroutine interpolateH2Ocont_PPC
84
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