psmile_transrot_dble.F90

Go to the documentation of this file.

!-----------------------------------------------------------------------
! Copyright 2006-2010, NEC Europe Ltd., London, UK.
! All rights reserved. Use is subject to OASIS4 license terms.
!-----------------------------------------------------------------------
!BOP
!
! !ROUTINE: PSMILe_transrot_dble
!
! !INTERFACE:
!
      subroutine psmile_transrot_dble ( flong, flati, rmlon, rmlat )
!
! !USES:
!
!      use PRISM_constants, only : len_cvs_string
!
      use PSMILe, only : ch_id, len_cvs_string
!
! !INPUT PARAMETERS:
!
      Double Precision, Intent (In)  :: flong, flati
!
!     Input: fLong: Geographical longitude
!            fLati: Geographical latitude
!            ...all in degrees ...
!
! !OUTPUT PARAMETERS:
!
      Double Precision, Intent (Out) :: rmlat, rmlon
!
!     Output:rmlon: transformed longitude
!            rmlat: transformed latitude
!            ...all in degrees ...
!
! !LOCAL VARIABLES
!
      Double Precision :: pif, pi

!rr   Double Precision :: grlam
      Double Precision :: fl
      Double Precision :: sinphi, phi
      Double Precision :: coslam, cosphi
!
! !DESCRIPTION:
!
!
! Routine kindly provided by C. Koeberle, R. Gerdes AWI Bremerhaven
! originally used to rotate part of the Atlantic model grid.
!
! The grid is rotated by 90 degree. The points are translated 
! by 90 deg towards the Equator. North and South pole are
! located on the Equator on the transformed grid.
!
!------------------------------------------------------------
!
! !REVISION HISTORY:
!
!   Date      Programmer   Description
! ----------  ----------   -----------
! 08.10.09    R. Redler    created
!
!EOP
!----------------------------------------------------------------------
!
!  $Id: psmile_transrot_dble.F90 2614 2010-09-30 12:26:43Z redler $
!  $Author: redler $
!
   Character(len=len_cvs_string), save :: mycvs = 
       '$Id: psmile_transrot_dble.F90 2614 2010-09-30 12:26:43Z redler $'
!
!----------------------------------------------------------------------

#ifdef VERBOSE
      print 9990, trim(ch_id), flong, flati
      call psmile_flushstd
#endif /* VERBOSE */

!rr
!rr  Model grid is rotated 30 deg to the west
!rr
!rr   GRlam = -30.0

      pi  = 4.*atan(1.)
      pif = pi/180.
!
!  Make sure that longitude is 0..360 deg.
!
      fl = Mod(flong+360.0d0,360.0d0)
!
!   Latitude
!
!rr   sinphi=cos( flati*pif ) * sin( (fl-grlam)*pif )
      sinphi=cos( flati*pif ) * sin( fl*pif )
      phi   =asin( sinphi )
      cosphi=cos(phi)
      rmlat =phi/pif
!
!   Longitude
!
      if (cosphi.ne.0.0) then
        coslam=sin( fLati*pif )/cosphi
        if(abs(coslam).gt.1.0.and.abs(coslam)-1.0.le.1.e-14) &
        coslam=sign(1.0d0,coslam)
        rmlon =acos( coslam )/pif
      else
        rmlon =0.0
        if (phi.lt.0.0) rmlon=180.0
      endif
!
!rr   ... should be >180deg. in the western model hemisphere
!rr
!rr   if (fl-grlam.gt.90.and.fl-grlam.lt.270.) rmlon=360.-rmlon
!rr   if (fl.gt.90.and.fl.lt.270.) rmlon=360.-rmlon
!
!     preserve sign when crossing the greenwich meridian
!
      if ( fl > 90 .and. fl < 270.0 ) rmlon = -rmlon
#ifdef VERBOSE
      print 9980, trim(ch_id), rmlon, rmlat
      call psmile_flushstd
#endif /* VERBOSE */
!
9990 format (1x, a, ': psmile_transrot_dble: in : ', 2f8.2)
9980 format (1x, a, ': psmile_transrot_dble: out: ', 2f8.2, ' eof')

      end subroutine psmile_transrot_dble