sptgpmd.f File Reference

Transform spectral to Mercator gradients. More...

Go to the source code of this file.

Functions/Subroutines
subroutine	sptgpmd (IROMB, MAXWV, KMAX, MI, MJ, KWSKIP, KGSKIP, NISKIP, NJSKIP, RLAT1, RLON1, DLAT, DLON, WAVE, XM, YM)
	This subprogram performs a spherical transform from spectral coefficients of scalar fields to gradient fields on a Mercator grid. More...

Detailed Description

Transform spectral to Mercator gradients.

Author

Iredell

Date

96-02-29

Definition in file sptgpmd.f.

Function/Subroutine Documentation

sptgpmd()

subroutine sptgpmd	(		IROMB,
			MAXWV,
			KMAX,
			MI,
			MJ,
			KWSKIP,
			KGSKIP,
			NISKIP,
			NJSKIP,
			RLAT1,
			RLON1,
			DLAT,
			DLON,
		real, dimension(*)	WAVE,
		real, dimension(*)	XM,
		real, dimension(*)	YM
	)

This subprogram performs a spherical transform from spectral coefficients of scalar fields to gradient fields on a Mercator grid.

The wave-space can be either triangular or rhomboidal. The wave and grid fields may have general indexing, but each wave field is in sequential 'IBM order', i.e. with zonal wavenumber as the slower index.

The Mercator grid is identified by the location of its first point and by its respective increments.

The transforms are all multiprocessed over sector points.

Transform several fields at a time to improve vectorization. Subprogram can be called from a multiprocessing environment.

Parameters

IROMB	Spectral domain shape (0 for triangular, 1 for rhomboidal)
MAXWV	Spectral truncation
KMAX	Number of fields to transform
MI	Number of points in the faster zonal direction
MJ	Number of points in the slower merid direction
KWSKIP	Skip number between wave fields (defaults to (MAXWV+1)*((IROMB+1)*MAXWV+2) if KWSKIP=0)
KGSKIP	Skip number between grid fields (defaults to MI*MJ if KGSKIP=0)
NISKIP	Skip number between grid i-points (defaults to 1 if NISKIP=0)
NJSKIP	Skip number between grid j-points (defaults to MI if NJSKIP=0)
RLAT1	Latitude of the first grid point in degrees
RLON1	Longitude of the first grid point in degrees
DLAT	Latitude increment in degrees such that D(PHI)/D(J)=DLAT*COS(PHI) where J is meridional index. DLAT is negative for grids indexed southward. (in terms of grid increment dy valid at latitude RLATI, the latitude increment DLAT is determined as DLAT=DPR*DY/(RERTH*COS(RLATI/DPR)) where DPR=180/PI and RERTH is Earth's radius)
DLON	Longitude increment in degrees such that D(LAMBDA)/D(I)=DLON where I is zonal index. DLON is negative for grids indexed westward.
WAVE	Wave fields
XM	Mercator x-gradients
YM	Mercator y-gradients

Author

Iredell

Date

96-02-29

Definition at line 53 of file sptgpmd.f.

References splaplac(), sptgpmv(), and spwget().