Move pi (and few others) to marbl_constants_mod

Pi is now hard-coded to be 3.14159265358979323846_r8, rather than computed in
marbl_ciso_set_interior. Also, marbl_ciso no longer has its own
marbl_seconds_in_year variable - uses marbl_constants_mod:spy instead.

src/marbl_ciso_mod.F90

@@ -73,9 +73,6 @@ module marbl_ciso_mod
      real (r8) :: Ca14CO3 ! local copy of model autotroph Ca14CO3
   end type autotroph_local_type
 
-  ! Module variables
-  real(r8) :: pi
-
   !-----------------------------------------------------------------------
   !  scalar constants for 14C decay calculation
   !-----------------------------------------------------------------------
@@ -354,6 +351,7 @@ subroutine marbl_ciso_set_interior_forcing( &
     use marbl_constants_mod    , only : R13c_std
     use marbl_constants_mod    , only : R14c_std
     use marbl_constants_mod    , only : spd
+    use marbl_constants_mod    , only : spy
     use marbl_diagnostics_mod  , only : store_diagnostics_ciso_interior
 
     implicit none
@@ -379,7 +377,6 @@ subroutine marbl_ciso_set_interior_forcing( &
     logical (log_kind) :: zero_mask
 
     real (r8) :: &
-         marbl_seconds_in_year, & 
          work1,     & ! temporaries
          ztop         ! depth of top of cell
 
@@ -538,14 +535,8 @@ subroutine marbl_ciso_set_interior_forcing( &
     ! Set module variables
     !-----------------------------------------------------------------------
 
-    ! FIXME #36: move this calculations to the init phase when 
-    !            the initialization is brought into this module
-
-    pi  = 4.0_r8 * atan( 1.0_r8 )
-
     !  Define decay variable for DI14C, using earlier defined half-life of 14C
-    marbl_seconds_in_year = 86400._r8 * 365._r8
-    c14_lambda_inv_sec = log(c2) / (c14_halflife_years * marbl_seconds_in_year)
+    c14_lambda_inv_sec = log(c2) / (c14_halflife_years * spy)
 
     !----------------------------------------------------------------------------------------
     ! Set cell attributes
@@ -1303,7 +1294,9 @@ subroutine fract_keller_morel( &
     !
     !   Developed by X. Giraud, ETH Zürich, 21.07.2008
     !---------------------------------------------------------------------------
-
+
+    use marbl_constants_mod, only : pi
+
     implicit none
 
     real (r8), intent(in) :: &
@@ -1323,8 +1316,7 @@ subroutine fract_keller_morel( &
     real (r8) :: &
          var, theta, eps_up
 
-    real (r8) :: &
-         pi, Vol, Qc, Surf, radius_m
+    real (r8) :: Vol, Qc, Surf, radius_m
 
     real (r8) :: &
          eps_diff   = 0.7_r8, & ! fractionation by diffusion, O'Leary, 1984

src/marbl_constants_mod.F90

@@ -7,19 +7,21 @@ module marbl_constants_mod
   save
 
   ! General constants
-  real(kind=r8), parameter, public :: &
-      c0     =    0.0_r8       , &
-      c1     =    1.0_r8       , &
-      c2     =    2.0_r8       , &
-      c3     =    3.0_r8       , &
-      c10    =   10.0_r8       , &
-      c1000  = 1000.0_r8       , &
-      p001   =  0.001_r8       , &
-      p5     =    0.5_r8
+  real(kind=r8), parameter, public ::        &
+      c0     =    0.0_r8                   , &
+      c1     =    1.0_r8                   , &
+      c2     =    2.0_r8                   , &
+      c3     =    3.0_r8                   , &
+      c10    =   10.0_r8                   , &
+      c1000  = 1000.0_r8                   , &
+      p001   =    0.001_r8                 , &
+      p5     =    0.5_r8                   , &
+      pi     =    3.14159265358979323846_r8
 
 ! Unit Conversion
   real(kind=r8), parameter, public :: &
       spd       = 86400.0_r8,          & ! number of seconds in a day
+      spy       = 365.0_r8*spd,        & ! number of seconds in a year
       dps       = c1 / spd,            & ! number of days in a second
       yps       = c1 / (365.0_r8*spd), & ! number of years in a second
       mpercm    = .01_r8                 ! meters per cm