module constants_mod ! ! Stefan Petri ! ! ! Defines useful constants for Earth. ! ! ! Constants are defined as real parameters. ! Constants are accessed through the "use" statement. ! ! The GFDL-provided FMS/MOM distribution uses for some different values ! than Aeolus. But when coupling MOM/FMS with Aeolus, we want ! to use consistent values throughout the model. ! Thus, this an alternate implementation of constants_mod for use ! when coupling with Aeolus. ! ! It might be more flexible and even cleaner to read namelist parameters ! at runtime. However, lots of modules in coupler, ocean, and CM2 atmosphere ! expect these to be compile-time constants. And it turned out to be really ugly ! to change all those modules for this small purpose. ! use mpp_mod, only: mpp_pe, mpp_root_pe use mpp_io_mod, only: mpp_close implicit none private character(len=128) :: version='$Id$' character(len=128) :: tagname='$Name: siena_201207 $' !dummy variable to use in HUGE initializations !real :: realnumber !------------ physical constants --------------- ! ! radius of the earth ! ! ! rotation rate of the planet (earth) ! ! ! acceleration due to gravity ! ! ! gas constant for dry air ! ! ! RDGAS / CP_AIR ! ! ! specific heat capacity of dry air at constant pressure ! ! ! specific heat capacity taken from McDougall (2002) "Potential Enthalpy ..." ! ! ! average density of sea water ! ! ! reciprocal of average density of sea water ! ! ! (kg/m^3)*(cal/kg/deg C)(joules/cal) = (joules/m^3/deg C) ! real, public, parameter :: RADIUS = 6371.0e3 real, public, parameter :: OMEGA = 7.292e-5 real, public, parameter :: GRAV = 9.80 real, public, parameter :: RDGAS = 287.04 real, public, parameter :: KAPPA = 2./7. real, public, parameter :: CP_AIR = RDGAS/KAPPA real, public, parameter :: CP_OCEAN = 3989.24495292815 real, public, parameter :: RHO0 = 1.035e3 real, public, parameter :: RHO0R = 1.0/RHO0 real, public, parameter :: RHO_CP = RHO0*CP_OCEAN !------------ water vapor constants --------------- ! ! Humidity factor. Controls the humidity content of the atmosphere through ! the Saturation Vapour Pressure expression when using DO_SIMPLE. ! ! ! gas constant for water vapor ! ! ! specific heat capacity of water vapor at constant pressure ! ! ! density of liquid water ! ! ! latent heat of evaporation ! ! ! latent heat of fusion ! ! ! latent heat of sublimation ! ! ! temp where fresh water freezes ! real, public, parameter :: ES0 = 1.0 real, public, parameter :: RVGAS = 461.50 real, public, parameter :: CP_VAPOR = 4.0*RVGAS real, public, parameter :: DENS_H2O = 1000. real, public, parameter :: HLV = 2.500e6 real, public, parameter :: HLF = 3.34e5 real, public, parameter :: HLS = HLV + HLF real, public, parameter :: TFREEZE = 273.16 !-------------- radiation constants ----------------- ! ! molecular weight of air ! ! ! molecular weight of water ! ! ! molecular weight of ozone ! ! ! molecular weight of carbon ! ! molecular weight of carbon dioxide ! ! molecular weight of molecular oxygen ! ! molecular weight of CFC-11 (CCl3F) ! ! molecular weight of CFC-21 (CCl2F2) ! ! ! diffusivity factor ! ! ! seconds in a day ! ! ! Avogadro's number ! ! ! mean sea level pressure ! ! ! mean sea level pressure ! real, public, parameter :: WTMAIR = 2.896440E+01 real, public, parameter :: WTMH2O = WTMAIR*(RDGAS/RVGAS) !pjp OK to change value because not used yet. !real, public, parameter :: WTMO3 = 47.99820E+01 real, public, parameter :: WTMOZONE = 47.99820 real, public, parameter :: WTMC = 12.00000 real, public, parameter :: WTMCO2 = 44.00995 real, public, parameter :: WTMO2 = 31.9988 real, public, parameter :: WTMCFC11 = 137.3681 real, public, parameter :: WTMCFC12 = 120.9135 real, public, parameter :: DIFFAC = 1.660000E+00 real, public, parameter :: SECONDS_PER_DAY = 8.640000E+04, SECONDS_PER_HOUR = 3600., SECONDS_PER_MINUTE=60. real, public, parameter :: AVOGNO = 6.023000E+23 real, public, parameter :: PSTD = 1.013250E+06 real, public, parameter :: PSTD_MKS = 101325.0 !real, public, parameter :: REARTH = 6.356766E+08 !pjp Not used anywhere. ! ! factor used to convert flux divergence to heating rate in degrees per day ! ! ! factor used to convert flux divergence to heating rate in degrees per day ! ! ! mixing ratio of molecular oxygen in air ! ! ! reference atmospheric density ! ! ! minimum value allowed as argument to log function ! real, public, parameter :: RADCON = ((1.0E+02*GRAV)/(1.0E+04*CP_AIR))*SECONDS_PER_DAY real, public, parameter :: RADCON_MKS = (GRAV/CP_AIR)*SECONDS_PER_DAY real, public, parameter :: O2MIXRAT = 2.0953E-01 real, public, parameter :: RHOAIR = 1.292269 real, public, parameter :: ALOGMIN = -50.0 !------------ miscellaneous constants --------------- ! ! Stefan-Boltzmann constant ! ! ! Von Karman constant ! ! ! ratio of circle circumference to diameter ! ! ! degrees per radian ! ! ! radians per degree ! ! ! equal to RAD_TO_DEG. Named RADIAN for backward compatability. ! ! ! converts rho*g*z (in mks) to dbars: 1dbar = 10^4 (kg/m^3)(m/s^2)m ! ! ! degrees Kelvin at zero Celsius ! ! ! a small number to prevent divide by zero exceptions ! !real, public, parameter :: STEFAN = 5.6734e-8 real, public, parameter :: STEFAN = 5.670367e-8 ! http://physics.nist.gov/cgi-bin/cuu/Value?sigma [CODATA 2014] real, public, parameter :: VONKARM = 0.40 real, public, parameter :: PI = 3.14159265358979323846 real, public, parameter :: RAD_TO_DEG=180./PI real, public, parameter :: DEG_TO_RAD=PI/180. real, public, parameter :: RADIAN = RAD_TO_DEG real, public, parameter :: C2DBARS = 1.e-4 real, public, parameter :: KELVIN = 273.15 real, public, parameter :: EPSLN = 1.0e-40 !----------------------------------------------------------------------- ! version and tagname published ! so that write_version_number can be called for constants_mod by fms_init public :: version, tagname !----------------------------------------------------------------------- public :: constants_init contains subroutine constants_init if (mpp_pe() == mpp_root_pe()) then write(*,*) version write(*,*) tagname write(*,*) 'RADIUS =', RADIUS write(*,*) 'OMEGA =', OMEGA write(*,*) 'GRAV =', GRAV write(*,*) 'RDGAS =', RDGAS write(*,*) 'CP_AIR = RDGAS/KAPPA = ', CP_AIR write(*,*) 'HLV =', HLV write(*,*) 'HLF =', HLF write(*,*) 'HLS = HLV+HLF =', HLS write(*,*) 'WTMH2O = WTMAIR*(RDGAS/RVGAS) = ', WTMH2O write(*,*) 'RADCON = ((1.0E+02*GRAV)/(1.0E+04*CP_AIR))*SECONDS_PER_DAY = ', RADCON write(*,*) 'RADCON_MKS = (GRAV/CP_AIR)*SECONDS_PER_DAY = ', RADCON_MKS write(*,*) 'STEFAN =', STEFAN end if end subroutine constants_init end module constants_mod ! ! ! 1. Renaming of constants. ! ! ! 2. Additional constants. ! ! ! Constants have been declared as type REAL, PARAMETER. ! ! The value a constant can not be changed in a users program. ! New constants can be defined in terms of values from the ! constants module using a parameter statement.

! ! The name given to a particular constant may be changed.

! ! Constants can be used on the right side on an assignment statement ! (their value can not be reassigned). ! ! ! !

!    use constants_mod, only:  TFREEZE, grav_new => GRAV
!    real, parameter :: grav_inv = 1.0 / grav_new
!    tempc(:,:,:) = tempk(:,:,:) - TFREEZE
!    geopotential(:,:) = height(:,:) * grav_new
!

! ! !