var/da/da_radiance/gsi_constants.f90

   1 module gsi_constants
   2 !$$$   module documentation block
   3 !                .      .    .                                       .
   4 ! module:    constants
   5 !   prgmmr: treadon          org: np23                date: 2003-09-25
   6 !
   7 ! abstract:  This module contains the definition of various constants
   8 !            used in the gsi code
   9 !
  10 ! program history log:
  11 !   2003-09-25  treadon - original code
  12 !   2004-03-02  treadon - allow global and regional constants to differ
  13 !   2004-06-16  treadon - update documentation
  14 !   2004-10-28  treadon - replace parameter tiny=1.e-12 with tiny_r_kind
  15 !                         and tiny_single
  16 !   2004-11-16  treadon - add huge_single, huge_r_kind parameters
  17 !   2005-01-27  cucurull - add ione
  18 !
  19 ! Subroutines Included:
  20 !   sub init_constants  - compute derived constants, set regional/global constants
  21 !
  22 ! Variable Definitions:
  23 !   see below
  24 !
  25 ! attributes:
  26 !   language: f90
  27 !   machine:  ibm RS/6000 SP
  28 !
  29 !$$$
  30   use gsi_kinds, only: r_single,r_kind,i_kind
  31   implicit none
  32
  33 ! Declare constants
  34   integer(i_kind) izero,ione
  35   real(r_kind) rearth,grav,omega,rd,rv,cp,cv,cvap,cliq
  36   real(r_kind) csol,hvap,hfus,psat,t0c,ttp,jcal,cp_mass
  37   real(r_kind) fv,deg2rad,rad2deg,pi,tiny_r_kind,huge_r_kind
  38   real(r_kind) ozcon,rozcon,tpwcon,rd_over_g,rd_over_cp,g_over_rd
  39   real(r_kind) amsua_clw_d1,amsua_clw_d2,constoz,zero,one,two,four
  40   real(r_kind) one_tenth,quarter,three,five
  41   real(r_kind) rearth_equator,stndrd_atmos_ps
  42   real(r_kind) semi_major_axis,semi_minor_axis,n_a,n_b
  43   real(r_kind) eccentricity,grav_polar,grav_ratio
  44   real(r_kind) grav_equator,earth_omega,grav_constant
  45   real(r_kind) flattening,eccentricity_linear,somigliana
  46   real(r_kind) dldt,dldti,hsub,psatk,tmix,xa,xai,xb,xbi
  47   real(r_kind) eps,epsm1,omeps
  48   real(r_kind) elocp,cpr,el2orc,cclimit,climit,epsq
  49   real(r_kind) pcpeff0,pcpeff1,pcpeff2,pcpeff3,rcp,c0,delta
  50   real(r_kind) h1000,factor1,factor2,rhcbot,rhctop,dx_max,dx_min,dx_inv
  51   real(r_kind) h300,half,cmr,cws,ke2,row,rrow
  52   real(r_single) zero_single,tiny_single,huge_single
  53
  54
  55 ! Define constants common to global and regional applications
  56 !           name     value                  description                     units
  57 !           ----     -----                  -----------                     -----
  58   parameter(rearth_equator= 6.37813662e6_r_kind) ! equatorial earth radius (m)
  59   parameter(omega  = 7.2921e-5_r_kind)  !  angular velocity of earth       (1/s)
  60   parameter(cp     = 1.0046e+3_r_kind)  !  specific heat of air @pressure  (J/kg/K)
  61   parameter(cvap   = 1.8460e+3_r_kind)  !  specific heat of h2o vapor      (J/kg/K)
  62   parameter(csol   = 2.1060e+3_r_kind)  !  specific heat of solid h2o (ice)(J/kg/K)
  63   parameter(hvap   = 2.5000e+6_r_kind)  !  latent heat of h2o condensation (J/kg)
  64   parameter(hfus   = 3.3358e+5_r_kind)  !  latent heat of h2o fusion       (J/kg)
  65   parameter(psat   = 6.1078e+2_r_kind)  !  pressure at h2o triple point    (Pa)
  66   parameter(t0c    = 2.7315e+2_r_kind)  !  temperature at zero celsius     (K)
  67   parameter(ttp    = 2.7316e+2_r_kind)  !  temperature at h2o triple point (K)
  68   parameter(jcal   = 4.1855e+0_r_kind)  !  joules per calorie              ()
  69   parameter(stndrd_atmos_ps = 1013.25e2_r_kind) ! 1976 US standard atmosphere ps   (Pa)
  70
  71 ! Numeric constants
  72   parameter(izero  = 0)
  73   parameter(ione   = 1)
  74   parameter(zero_single = 0.0_r_single)
  75   parameter(zero   = 0.0_r_kind)
  76   parameter(one_tenth  = 0.10_r_kind)
  77   parameter(quarter= 0.25_r_kind)
  78   parameter(one    = 1.0_r_kind)
  79   parameter(two    = 2.0_r_kind)
  80   parameter(three  = 3.0_r_kind)
  81   parameter(four   = 4.0_r_kind)
  82   parameter(five   = 5.0_r_kind)
  83
  84 ! Constants for gps refractivity
  85   parameter(n_a=77.6_r_kind) !K/mb
  86   parameter(n_b=3.73e+5_r_kind) !K^2/mb
  87
  88 ! Parameters below from WGS-84 model software inside GPS receivers.
  89   parameter(semi_major_axis = 6378.1370e3_r_kind)    !                     (m)
  90   parameter(semi_minor_axis = 6356.7523142e3_r_kind) !                     (m)
  91   parameter(grav_polar = 9.8321849378_r_kind)        !                     (m/s2)
  92   parameter(grav_equator = 9.7803253359_r_kind)      !                     (m/s2)
  93   parameter(earth_omega = 7.292115e-5_r_kind)        !                     (rad/s)
  94   parameter(grav_constant = 3.986004418e14_r_kind)   !                     (m3/s2)
  95
  96 ! Derived geophysical constants
  97   parameter(flattening = (semi_major_axis-semi_minor_axis)/semi_major_axis)!()
  98   parameter(somigliana = &
  99        (semi_minor_axis/semi_major_axis) * (grav_polar/grav_equator) - one)!()
 100   parameter(grav_ratio = (earth_omega*earth_omega * &
 101        semi_major_axis*semi_major_axis * semi_minor_axis) / grav_constant) !()
 102
 103 ! Derived thermodynamic constants
 104   parameter ( dldti = cvap-csol )
 105   parameter ( hsub = hvap+hfus )
 106   parameter ( psatk = psat*0.001_r_kind )
 107   parameter ( tmix = ttp-20._r_kind )
 108   parameter ( elocp = hvap/cp )
 109   parameter ( rcp  = one/cp )
 110
 111 ! Constants used in GFS moist physics
 112   parameter ( h300 = 300._r_kind )
 113   parameter ( half = 0.5_r_kind )
 114   parameter ( cclimit = 0.001_r_kind )
 115   parameter ( climit = 1.e-20_r_kind)
 116   parameter ( epsq = 2.e-12_r_kind )
 117   parameter ( h1000 = 1000.0_r_kind)
 118   parameter ( rhcbot=0.85_r_kind )
 119   parameter ( rhctop=0.85_r_kind )
 120   parameter ( dx_max=-8.8818363_r_kind )
 121   parameter ( dx_min=-5.2574954_r_kind )
 122   parameter ( dx_inv=one/(dx_max-dx_min) )
 123   parameter ( c0=0.002_r_kind )
 124   parameter ( delta=0.6077338_r_kind )
 125   parameter ( pcpeff0=1.591_r_kind )
 126   parameter ( pcpeff1=-0.639_r_kind )
 127   parameter ( pcpeff2=0.0953_r_kind )
 128   parameter ( pcpeff3=-0.00496_r_kind )
 129   parameter ( cmr = one/0.0003_r_kind )
 130   parameter ( cws = 0.025_r_kind )
 131   parameter ( ke2 = 0.00002_r_kind )
 132   parameter ( row = 1000._r_kind )
 133   parameter ( rrow = one/row )
 134
 135 ! Constant used to process ozone
 136   parameter ( constoz = 604229.0_r_kind)
 137
 138 ! Constants used in cloud liquid water correction for AMSU-A
 139 ! brightness temperatures
 140   parameter ( amsua_clw_d1 = 0.754_r_kind )
 141   parameter ( amsua_clw_d2 = -2.265_r_kind )
 142
 143 contains
 144 #include "init_constants_derived.inc"
 145 ! Routine never used in wrfvar
 146 ! #include "init_constants.inc"
 147
 148 end module gsi_constants