[Wrf-users] DY increases and does not take effect - WPS/ARWPost

Ricardo da Silva rmsilva at ucar.edu
Wed Jul 8 13:12:52 MDT 2009


Hi,

I've been trying to define a grid using WPS/geogrid, and checking grid
position and definitions using ARWPost + GrADS.

DX has been setup for 9259m, and DY for 12000m, but as far as I'm
increasing DY, the grid does not change. I reach a limit of 20000 m and
nothing happens. It always looks like using a single DS (DY=DX).

Greping the WPS code I've found this code
(WPS/geogrid/src/module_map_utils.f90):
---------------------------^^ cut here ^^-----------------------------
   SUBROUTINE ijll_merc(i, j, proj, lat, lon)

      ! Compute the lat/lon from i/j for mercator projection

      IMPLICIT NONE
      REAL,INTENT(IN)               :: i
      REAL,INTENT(IN)               :: j
      TYPE(proj_info),INTENT(IN)    :: proj
      REAL, INTENT(OUT)             :: lat
      REAL, INTENT(OUT)             :: lon


      lat = 2.0*ATAN(EXP(proj%dlon*(proj%rsw +
j-proj%knownj)))*deg_per_rad - 90.
      lon = (i-proj%knowni)*proj%dlon*deg_per_rad + proj%lon1
      IF (lon.GT.180.) lon = lon - 360.
      IF (lon.LT.-180.) lon = lon + 360.
      RETURN

   END SUBROUTINE ijll_merc
---------------------------^^ cut here ^^-----------------------------

line:
lat = 2.0*ATAN(EXP(proj%dlon*(proj%rsw + j-proj%knownj)))*deg_per_rad - 90.

it does not should be using proj%dlat instead of dlon?
If yes, it should be defined at set_merc subroutine?

Anybody help me?

Regards,

Ricardo.



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