mo_constants.f90

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!> \file mo_constants.f90
!> \brief \copybrief mo_constants
!> \details \copydetails mo_constants
 
!> \brief Provides computational, mathematical, physical, and file constants
!> \details Provides computational constants like epsilon, mathematical constants such as Pi,
!! physical constants such as the Stefan-Boltzmann constant, and file units for some standard streams
!! such as standard in.
!> \author Matthias Cuntz
!> \date Nov 2011
!> \copyright Copyright 2005-\today, the CHS Developers, Sabine Attinger: All rights reserved.
!! FORCES is released under the LGPLv3+ license \license_note
module mo_constants
 
  use mo_kind, only : sp, dp, i4, i8
  use, intrinsic :: iso_fortran_env, only : input_unit, output_unit, error_unit
 
  implicit none
 
  ! Mathematical
  !> Pi in double precision
  real(dp), parameter :: pi_dp = 3.141592653589793238462643383279502884197_dp    ! Pi
  !> Pi in single precision
  real(sp), parameter :: pi_sp = 3.141592653589793238462643383279502884197_sp
  !> Pi/2 in double precision
  real(dp), parameter :: pio2_dp = 1.57079632679489661923132169163975144209858_dp  ! Pi/2
  !> Pi/2 in single precision
  real(sp), parameter :: pio2_sp = 1.57079632679489661923132169163975144209858_sp
  !> 2*Pi in double precision
  real(dp), parameter :: twopi_dp = 6.283185307179586476925286766559005768394_dp    ! 2*Pi
  !> 2*Pi in single precision
  real(sp), parameter :: twopi_sp = 6.283185307179586476925286766559005768394_sp
  !> Square root of 2 in double precision
  real(dp), parameter :: sqrt2_dp = 1.41421356237309504880168872420969807856967_dp  ! Sqrt(2)
  !> Square root of 2 in single precision
  real(sp), parameter :: sqrt2_sp = 1.41421356237309504880168872420969807856967_sp
  !> 2/3 in double precision
  real(dp), parameter :: twothird_dp = 0.6666666666666666666666666666666666667_dp      ! 2/3
  !> 2/3 in single precision
  real(sp), parameter :: twothird_sp = 0.6666666666666666666666666666666666667_sp
  !> 1/3 in double precision
  real(dp), parameter :: onethird_dp = 0.3333333333333333333333333333333333333_dp      ! 1/3
  !> 1/3 in single precision
  real(sp), parameter :: onethird_sp = 0.3333333333333333333333333333333333333_sp      ! 1/3
  !> degree to radian conversion (pi/180) in double precision
  real(dp), parameter :: deg2rad_dp = pi_dp / 180._dp                       ! deg2rad
  !> degree to radian conversion (pi/180) in double precision
  real(sp), parameter :: deg2rad_sp = pi_sp / 180._sp
  !> radian to conversion (180/pi) in double precision
  real(dp), parameter :: rad2deg_dp = 180._dp / pi_dp                       ! rad2deg
  !> radian to degree conversion (180/pi) in single precision
  real(sp), parameter :: rad2deg_sp = 180._sp / pi_sp
 
  ! Time conversion
  !> Seconds per day [s] in single precision
  real(sp), public, parameter :: secday_sp = 86400.0_sp
  real(dp), public, parameter :: secday_dp = 86400.0_dp  !< secday [s]
  real(dp), public, parameter :: dayhours = 24.0_dp  !< hours per day
  real(dp), public, parameter :: yearmonths = 12.0_dp  !< months per year
  real(dp), public, parameter :: yeardays = 365.0_dp  !< days in a year
  real(dp), public, parameter :: daysecs = 86400.0_dp  !< sec in a day
  real(dp), public, parameter :: hoursecs = 3600.0_dp  !< seconds per hour
 
  ! Physical
  !> Psychrometric constant [kPa K^-1] in double precision
  real(dp), parameter :: psychro_dp = 0.0646_dp                 ! psychrometric constant [kPa C-1]
  !> Psychrometric constant [kPa K^-1] in sibgle precision
  real(sp), parameter :: psychro_sp = 0.0646_sp
  !> Gravity accelaration [m^2 s^-1] in double precision
  real(dp), parameter :: gravity_dp = 9.81_dp                      ! Gravity acceleration [m^2/s]
  !> Gravity accelaration [m^2 s^-1] in single precision
  real(sp), parameter :: gravity_sp = 9.81_sp
  !>  Solar constant in [J m^-2 s^-1] in double precision
  real(dp), parameter :: solarconst_dp = 1367._dp                   ! Solar constant in [W m-2 = kg s-3]
  !>  Solar constant in [J m^-2 s^-1] in single precision
  real(sp), parameter :: solarconst_sp = 1367._sp
  !> Specific heat for vaporization of water in [J m-2 mm-1] in double precision
  real(dp), parameter :: specheatet_dp = 2.45e06_dp                ! Specific heat in [W s m-2 mm-1 = kg s-2 mm-1]
  !> Specific heat for vaporization of water in [J m-2 mm-1] in single precision
  real(sp), parameter :: specheatet_sp = 2.45e06_sp
  !> Standard temperature [K] in double precision
  real(dp), parameter :: t0_dp = 273.15_dp                    ! Celcius <-> Kelvin [K]
  !> Standard temperature [K] in single precision
  real(sp), parameter :: t0_sp = 273.15_sp
  !> Stefan-Boltzmann constant [W m^-2 K^-4] in double precision
  real(dp), parameter :: sigma_dp = 5.67e-08_dp                  ! Stefan-Boltzmann constant [W/m^2/K^4]
  !> Stefan-Boltzmann constant [W m^-2 K^-4] in single precision
  real(sp), parameter :: sigma_sp = 5.67e-08_sp
  !> Earth radius [m] in single precision
  real(sp), parameter :: radiusearth_sp = 6371228._sp
  !> Earth radius [m] in double precision
  real(dp), parameter :: radiusearth_dp = 6371228._dp
 
  ! standard atmospehere
  !> Standard pressure [Pa] in double precision
  real(dp), parameter :: p0_dp = 101325._dp                   ! Standard pressure [Pa]
  !> Standard pressure [Pa] in single precision
  real(sp), parameter :: p0_sp = 101325._sp
  !> standard density  [kg m^-3] in double precision
  real(dp), parameter :: rho0_dp = 1.225_dp                    ! Standard air density
  !> standard density  [kg m^-3] in single precision
  real(sp), parameter :: rho0_sp = 1.225_sp
  !> specific heat capacity of air [J kg^-1 K^-1] in double precision
  real(dp), parameter :: cp0_dp = 1005.0_dp                   ! Standard specific heat of air
  !> specific heat capacity of air [J kg^-1 K^-1] in single precision
  real(sp), parameter :: cp0_sp = 1005.0_sp
  !> specific heat capacity of water [J kg^-1 K^-1] in double precision
  real(dp), parameter :: cp_w_dp = 4.19_dp
  !> specific heat capacity of water [J kg^-1 K^-1] in single precision
  real(sp), parameter :: cp_w_sp = 4.19_sp
 
  !> Pi in double precision
  real(dp), parameter :: pi_d = 3.141592653589793238462643383279502884197_dp      ! Pi
  !> Pi in single precision
  real(sp), parameter :: pi = 3.141592653589793238462643383279502884197_sp
  !> Pi/2 in double precision
  real(dp), parameter :: pio2_d = 1.57079632679489661923132169163975144209858_dp    ! Pi/2
  !> Pi/2 in single precision
  real(sp), parameter :: pio2 = 1.57079632679489661923132169163975144209858_sp
  !> 2*Pi in double precision
  real(dp), parameter :: twopi_d = 6.283185307179586476925286766559005768394_dp      ! 2*Pi
  !> 2*Pi in single precision
  real(sp), parameter :: twopi = 6.283185307179586476925286766559005768394_sp
  !> Square root of 2 in double precision
  real(dp), parameter :: sqrt2_d = 1.41421356237309504880168872420969807856967_dp    ! Sqrt(2)
  !> Square root of 2 in single precision
  real(sp), parameter :: sqrt2 = 1.41421356237309504880168872420969807856967_sp
  !> Euler''s constant in double precision
  real(dp), parameter :: euler_d = 0.5772156649015328606065120900824024310422_dp     ! Euler
  !> Euler''s constant in single precision
  real(sp), parameter :: euler = 0.5772156649015328606065120900824024310422_sp
 
  ! Standard file units
  !> Standard input file unit
  ! integer, parameter :: nin  = 5   ! standard input stream
  integer, parameter :: nin = input_unit   ! standard input stream
  !> Standard output file unit
  ! integer, parameter :: nout = 6   ! standard output stream
  integer, parameter :: nout = output_unit   ! standard output stream
  !> Standard error file unit
  ! integer, parameter :: nerr = 0   ! error output stream
  integer, parameter :: nerr = error_unit   ! error output stream
  !> Standard file unit for namelist
  integer, parameter :: nnml = 100 ! namelist unit
 
  ! computational, these values need to be the same!!!
  real(sp), public, parameter :: nodata_sp = -9999.0_sp                  !< [-]     global no data value
  real(dp), public, parameter :: nodata_dp = -9999.0_dp                  !< [-]     global no data value
  integer(i4), public, parameter :: nodata_i4 = int(nodata_dp)           !< [-]     global no data value
  integer(i8), public, parameter :: nodata_i8 = int(nodata_dp, kind=i8)  !< [-]     global no data value
  !> epsilon(1.0) in double precision
  real(dp), public, parameter :: eps_dp = epsilon(1.0_dp)
  !> epsilon(1.0) in single precision
  real(sp), public, parameter :: eps_sp = epsilon(1.0_sp)
 
end module mo_constants