time_manager.f90

CCSM Research Tools: Community Atmosphere Model (CAM)

   start_date = esmf_dateinit(rst_type, rst_start_ymd, rst_start_tod, rc)
   call chkrc(rc, sub//': error return from esmf_dateinit: setting start_date')

! Initialize current date.

   curr_date = esmf_dateinit(rst_type, rst_curr_ymd, rst_curr_tod, rc)
   call chkrc(rc, sub//': error return from esmf_dateinit: setting curr_date')

! Initialize stop date.

   if ( stop_ymd /= uninit_int ) then
      stop_date = esmf_dateinit(rst_type, stop_ymd, stop_tod, rc)
   else if ( nestep /= uninit_int ) then
      if ( nestep >= 0 ) then
         stop_date = esmf_dateincrementsec(start_date, dtime*nestep, rc)
      else
         stop_date = esmf_dateincrementday(start_date, -nestep, rc)
      end if
   else if ( nelapse /= uninit_int ) then
      if ( nelapse >= 0 ) then
         stop_date = esmf_dateincrementsec(curr_date, dtime*nelapse, rc)
      else
         stop_date = esmf_dateincrementday(curr_date, -nelapse, rc)
      end if
   else
      stop_date = esmf_dateinit(rst_type, rst_stop_ymd, rst_stop_tod, rc)
   end if
   call chkrc(rc, sub//': error return setting stop_date')

! Check that stop date is later than current date.

   call esmf_dateislater(curr_date, stop_date, islater, rc)
   call chkrc(rc, sub//': error return from esmf_dateislater: comparing start and stop dates')
   if ( .not. islater ) then
      write(6,*)sub,': stop date must be specified later than current date: '
      call esmf_dateget(curr_date, ymd, tod)
      write(6,*)' Current date (ymd tod): ', ymd, tod
      call esmf_dateget(stop_date, ymd, tod)
      write(6,*)' Stop date (ymd tod): ', ymd, tod
      call endrun
   end if
   call esmf_dateget(stop_date, rst_stop_ymd, rst_stop_tod)

! Restart a time manager.

   tm_id = esmf_timemgrrestartread(rst_type, rst_nstep, rst_step_days, rst_step_sec, rst_start_ymd, &
                                  rst_start_tod, rst_stop_ymd, rst_stop_tod, rst_ref_ymd, rst_ref_tod, &
                                  rst_curr_ymd, rst_curr_tod, rc)
   call chkrc(rc, sub//': error return from esmf_timemgrrestartread')

! Advance the timestep.  Data from the restart file corresponds to the
! last timestep of the previous run.

   call advance_timestep()

!  Set flag that this is the first timestep of the restart run.

   tm_first_restart_step = .true.

! Initialize date used for perpetual calendar day calculation.

   if ( rst_perp_cal ) then
      tm_perp_date = esmf_dateinit(rst_type, rst_perp_ymd, 0, rc)
      call chkrc(rc, sub//': error return from esmf_dateinit: setting tm_perp_date')
      tm_perp_calendar = .true.
   end if

! Set variables from "comtim.h interface" for backwards compatibility.

! Calculation of ending timestep number (nestep) assumes a constant stepsize.
   ntspday = 86400/dtime
   diff = esmf_timeinit()
   call esmf_datediff(start_date, stop_date, diff, islater, rc)
   call chkrc(rc, sub//': error return from esmf_datediff calculating nestep')
   call esmf_timeget(diff, ndays, nsecs, rc)
   call chkrc(rc, sub//': error return from esmf_timeget calculating nestep')
   nestep = ntspday*ndays + nsecs/dtime
   if ( mod(nsecs,dtime) /= 0 ) nestep = nestep + 1

! Print configuration summary to log file (stdout).

   if (masterproc) then
      call timemgr_print()
   end if

end subroutine timemgr_restart
!=========================================================================================

subroutine timemgr_print()

   implicit none

! Local variables
   character(len=*), parameter :: sub = 'timemgr_print'
   integer :: rc
   integer :: day, sec, ymd, tod
   character(len=32) :: cal     ! Calendar to use in date calculations.
   integer ::&                  ! Data required to restart time manager:
      type      = uninit_int,  &! calendar type
      nstep     = uninit_int,  &! current step number
      step_days = uninit_int,  &! days component of timestep size
      step_sec  = uninit_int,  &! seconds component of timestep size
      start_ymd = uninit_int,  &! start date
      start_tod = uninit_int,  &! start time of day
      stop_ymd  = uninit_int,  &! stop date
      stop_tod  = uninit_int,  &! stop time of day
      ref_ymd   = uninit_int,  &! reference date
      ref_tod   = uninit_int,  &! reference time of day
      curr_ymd  = uninit_int,  &! current date
      curr_tod  = uninit_int    ! current time of day
!-----------------------------------------------------------------------------------------

   call esmf_timemgrrestartwrite(tm_id, type, nstep, step_days, step_sec, &
                                start_ymd, start_tod, stop_ymd, stop_tod, ref_ymd, &
                                ref_tod, curr_ymd, curr_tod, rc)
   call chkrc(rc, sub//': error return from esmf_timemgrrestartwrite')

   write(6,*)' ********** Time Manager Configuration **********'

   if ( type == esmf_no_leap ) then
      cal = 'NO_LEAP'
   else if ( type == esmf_gregorian ) then
      cal = 'GREGORIAN'
   end if

   write(6,*)'  Calendar type:            ',trim(cal)
   write(6,*)'  Timestep size (seconds):  ', (step_days*86400 + step_sec)
   write(6,*)'  Start date (ymd tod):     ', start_ymd, start_tod
   write(6,*)'  Stop date (ymd tod):      ', stop_ymd, stop_tod
   write(6,*)'  Reference date (ymd tod): ', ref_ymd, ref_tod
   write(6,*)'  Current step number:      ', nstep
   write(6,*)'  Ending step number:       ', nestep
   write(6,*)'  Current date (ymd tod):   ', curr_ymd, curr_tod

   if ( tm_perp_calendar ) then
      call esmf_dateget(tm_perp_date, ymd, tod)
      write(6,*)'  Use perpetual diurnal cycle date (ymd): ', ymd
   end if

   write(6,*)' ************************************************'

end subroutine timemgr_print
!=========================================================================================

subroutine advance_timestep()

! Increment the timestep number.

   implicit none
   
! Local variables
   character(len=*), parameter :: sub = 'advance_timestep'
   integer :: rc
!-----------------------------------------------------------------------------------------

   call esmf_timemgradvance(tm_id, rc)
   call chkrc(rc, sub//': error return from esmf_timemgradvance')

! Set first step flag off.

   tm_first_restart_step = .false.

end subroutine advance_timestep
!=========================================================================================

function get_step_size()

! Return the step size in seconds.

   implicit none
   
! Return value
   integer :: get_step_size

! Local variables
   character(len=*), parameter :: sub = 'get_step_size'
   integer :: days, seconds
   integer :: rc
!-----------------------------------------------------------------------------------------

   call esmf_timemgrgetstepsize(tm_id, days, seconds, rc)
   call chkrc(rc, sub//': error return from esmf_timemgrgetstepsize')
   get_step_size = 86400*days + seconds

end function get_step_size
!=========================================================================================

function get_nstep()

! Return the timestep number.

   implicit none
   
! Return value
   integer :: get_nstep

! Local variables
   character(len=*), parameter :: sub = 'get_nstep'
   integer :: rc
!-----------------------------------------------------------------------------------------

   get_nstep = esmf_timemgrgetnstep(tm_id, rc)
   call chkrc(rc, sub//': error return from esmf_timemgrgetnstep')

end function get_nstep
!=========================================================================================

subroutine get_curr_date(yr, mon, day, tod, offset)

! Return date components valid at end of current timestep with an optional
! offset (positive or negative) in seconds.

   implicit none
   
! Arguments
   integer, intent(out) ::&
      yr,    &! year
      mon,   &! month
      day,   &! day of month
      tod     ! time of day (seconds past 0Z)

   integer, optional, intent(in) :: offset  ! Offset from current time in seconds.
                                            ! Positive for future times, negative 
                                            ! for previous times.

! Local variables
   character(len=*), parameter :: sub = 'get_curr_date'
   integer :: rc
   type(esmf_date) :: date
   type(esmf_time) :: off
   integer :: ymd
!-----------------------------------------------------------------------------------------

   date = esmf_timemgrgetcurrdate(tm_id, rc)
   call chkrc(rc, sub//': error return from esmf_timemgrgetcurrdate')

   if (present(offset)) then
      if (offset > 0) then
         date = esmf_dateincrementsec(date, offset, rc)
         call chkrc(rc, sub//': error incrementing current date')
      else if (offset < 0) then
         off = esmf_timeinit(0, -offset, rc)
         call chkrc(rc, sub//': error setting offset time type')
         date = esmf_datedecrement(date, off, rc)
         call chkrc(rc, sub//': error decrementing current date')
      end if
   end if

   call esmf_dateget(date, ymd, tod, rc)
   call chkrc(rc, sub//': error return from esmf_dateget')
   yr = ymd/10000
   mon = mod(ymd, 10000) / 100
   day = mod(ymd, 100)

end subroutine get_curr_date
!=========================================================================================

subroutine get_perp_date(yr, mon, day, tod)

! Return time of day valid at end of current timestep and the components
! of the perpetual date.

   implicit none
   
! Arguments
   integer, intent(out) ::&
      yr,    &! year
      mon,   &! month
      day,   &! day of month
      tod     ! time of day (seconds past 0Z)

! Local variables
   character(len=*), parameter :: sub = 'get_perp_date'
   integer :: rc
   type(esmf_date) :: date
   integer :: ymd, idum
!-----------------------------------------------------------------------------------------

   date = esmf_timemgrgetcurrdate(tm_id, rc)
   call chkrc(rc, sub//': error return from esmf_timemgrgetcurrdate')

   call esmf_dateget(date, idum, tod, rc)
   call chkrc(rc, sub//': error return from esmf_dateget')
   call esmf_dateget(tm_perp_date, ymd, idum, rc)
   call chkrc(rc, sub//': error return from esmf_dateget')
   yr = ymd/10000
   mon = mod(ymd, 10000) / 100
   day = mod(ymd, 100)

end subroutine get_perp_date
!=========================================================================================

subroutine get_prev_date(yr, mon, day, tod)

! Return date components valid at beginning of current timestep.

   implicit none
   
! Arguments
   integer, intent(out) ::&
      yr,    &! year
      mon,   &! month
      day,   &! day of month
      tod     ! time of day (seconds past 0Z)

! Local variables
   character(len=*), parameter :: sub = 'get_prev_date'
   integer :: rc
   type(esmf_date) :: date
   integer :: ymd
!-----------------------------------------------------------------------------------------

   date = esmf_timemgrgetprevdate(tm_id, rc)
   call chkrc(rc, sub//': error return from esmf_timemgrgetprevdate')

   call esmf_dateget(date, ymd, tod, rc)
   call chkrc(rc, sub//': error return from esmf_dateget')
   yr = ymd/10000
   mon = mod(ymd, 10000) / 100
   day = mod(ymd, 100)

end subroutine get_prev_date
!=========================================================================================

subroutine get_start_date(yr, mon, day, tod)

! Return date components valid at beginning of initial run.

   implicit none
   
! Arguments
   integer, intent(out) ::&
      yr,    &! year
      mon,   &! month