params

! BROADLY USED PARAMETERS:
!_________________________________________________
! i/o file unit numbers
      INTEGER kout, kin
! output
      PARAMETER(kout=53)
! input
      PARAMETER(kin=12)
!_________________________________________________
! altitude, wavelength, time (or solar zenith angle) grids
      INTEGER kz, kw, kt
! altitude
      PARAMETER(kz=125)
! wavelength
      PARAMETER(kw=1200)
! time/sza
      PARAMETER(kt=500)
!_________________________________________________

! Choice of data set for cross sections and quantum yields

      INTEGER, PARAMETER :: vers=2

! overwrites mabs and myld to enforce TUV or MCM dataset
! used for calculation of photolysis data AND transmission
! vers = 0: choose XS/QY individually
! vers = 1: TUV standard version
! vers = 2: MCM/GECKO-A standard version

! Parameters for character lengths/array size of log messages:
      INTEGER, PARAMETER ::  nlog = 10, llog = 100
      INTEGER, PARAMETER ::  lspc = 25

! Option for alternative quantum yield estimate for OH-subst. aldehydes
! swOH = 1: Use estimate of unsubstituted aldehyde
! swOH = 2: Use glycolaldehyde (qy = 0.75) as surrogate
      INTEGER, PARAMETER ::  swOH = 2
      REAL(4), PARAMETER ::  qyOH = 0.75
!_________________________________________________
! number of weighting functions
      INTEGER ks, kj, lcl
!  wavelength dependent
      PARAMETER(ks=60)
!  wavelength and altitude dependent
      PARAMETER(kj=500)
!  length of character of labels
      PARAMETER(lcl=50)

! delta for adding points at beginning or end of data grids
      REAL deltax
      PARAMETER (deltax = 1.E-5)

! some constants...

! pi:
      REAL pi
      PARAMETER(pi=3.1415926535898)

! radius of the earth, km:
      REAL radius
      PARAMETER(radius=6.371E+3)

! Planck constant x speed of light, J m

      REAL hc
      PARAMETER(hc = 6.626068E-34 * 2.99792458E8)

! largest number of the machine:
      REAL largest
      PARAMETER(largest=1.E+36)

! small numbers (positive and negative)
      REAL pzero, nzero
      PARAMETER(pzero = +10./largest)
      PARAMETER(nzero = -10./largest)

! machine precision

      REAL precis
      PARAMETER(precis = 1.e-7)

! More physical constants:
!_________________________________________________________________
! Na = 6.022142E23  mol-1       = Avogadro constant
! kb = 1.38065E-23  J K-1       = Boltzmann constant
! R  = 8.31447      J mol-1 K-1 = molar gas constant
! h  = 6.626068E-34 J s         = Planck constant
! c  = 2.99792458E8 m s-1       = speed of light in vacuum
! G  = 6.673E-11    m3 kg-1 s-2 = Newtonian constant of gravitation
! sb = 5.67040E-8   W m-2 K-4   = Stefan-Boltzmann constant
!_________________________________________________________________
! (1) From NIST Reference on Constants, Units, and Uncertainty
! http://physics.nist.gov/cuu/index.html Oct. 2001.
! (2) These constants are not assigned to variable names;  in other
! words this is not Fortran code, but only a text table for quick
! reference.  To use, you must declare a variable name/type and
! assign the value to that variable. Or assign as parameter (see
! example for pi above).