pesg::hgrid_ak_rr Interface Reference

Private Member Functions
subroutine	hgrid_ak_rr (lx, ly, nx, ny, A, K, plat, plon, pazi, delx, dely, glat, glon, garea, ff)
	Use a and k as the parameters of an Extended Schmidt-transformed Gnomonic (ESG) mapping centered at (plat,plon) and twisted about this center by an azimuth angle of pazi counterclockwise (these angles in radians). More...
subroutine	hgrid_ak_rr_c (lx, ly, nx, ny, a, k, plat, plon, pazi, delx, dely, glat, glon, garea, dx, dy, angle_dx, angle_dy, ff)
	Use a and k as the parameters of an extended Schmidt-transformed gnomonic (ESG) mapping centered at (plat,plon) and twisted about this center by an azimuth angle of pazi counterclockwise (these angles in radians). More...

Detailed Description

Definition at line 44 of file pesg.f90.

Constructor & Destructor Documentation

hgrid_ak_rr()

subroutine pesg::hgrid_ak_rr::hgrid_ak_rr ( integer(spi), intent(in)  lx, integer(spi), intent(in)  ly, integer(spi), intent(in)  nx, integer(spi), intent(in)  ny, real(dp), intent(in)  A, real(dp), intent(in)  K, real(dp), intent(in)  plat, real(dp), intent(in)  plon, real(dp), intent(in)  pazi, real(dp), intent(in)  delx, real(dp), intent(in)  dely, real(dp), dimension(lx:lx+nx ,ly:ly+ny ), intent(out)  glat, real(dp), dimension(lx:lx+nx ,ly:ly+ny ), intent(out)  glon, real(dp), dimension(lx:lx+nx-1,ly:ly+ny-1), intent(out)  garea, logical, intent(out)  ff  )

private

Use a and k as the parameters of an Extended Schmidt-transformed Gnomonic (ESG) mapping centered at (plat,plon) and twisted about this center by an azimuth angle of pazi counterclockwise (these angles in radians).

Assume the radius of the earth is unity, and using the central mapping point as the coordinate origin, set up the grid with central x-spacing delx and y-spacing dely. The grid index location of the left-lower corner of the domain is (lx,ly) (typically both NEGATIVE). The numbers of the grid spaces in x and y directions are nx and ny. (Note that, for a centered rectangular grid lx and ly are negative and, in magnitude, half the values of nx and ny respectively.) Return the latitude and longitude, in radians again, of the grid points thus defined in the arrays, glat and glon, and return a rectangular array, garea, of dimensions nx-1 by ny-1, that contains the areas of each of the grid cells

If all goes well, return a lowered failure flag, ff=.false. . But if, for some reason, it is not possible to complete this task, return the raised failure flag, ff=.TRUE. .

Parameters

[in]	lx	center-relative grid index in x of left edge of the domain
[in]	ly	center-relative grid index in y of lower edge of the domain
[in]	nx	number of grid spaces in x
[in]	ny	number of grid spaces in y
[in]	A	parameter of the ESG mapping centered at (plat,plon)
[in]	K	parameter of the ESG mapping centered at (plat,plon)
[in]	plat	latitude of projection center of mapping (radians)
[in]	plon	longitude of projection center of mapping (radians)
[in]	pazi	azimuth of orientation of mapping at its center
[in]	delx	central x-spacing of the grid (radians)
[in]	dely	central y-spacing of the grid (radians)
[out]	glat	grid points' latitudes
[out]	glon	grid points' longitudes
[out]	garea	array of grid-cell areas (steradians)
[out]	ff	failure flag

Author

R. J. Purser

Definition at line 1221 of file pesg.f90.

Member Function/Subroutine Documentation

hgrid_ak_rr_c()

subroutine pesg::hgrid_ak_rr::hgrid_ak_rr_c ( integer(spi), intent(in)  lx, integer(spi), intent(in)  ly, integer(spi), intent(in)  nx, integer(spi), intent(in)  ny, real(dp), intent(in)  a, real(dp), intent(in)  k, real(dp), intent(in)  plat, real(dp), intent(in)  plon, real(dp), intent(in)  pazi, real(dp), intent(in)  delx, real(dp), intent(in)  dely, real(dp), dimension(lx:lx+nx ,ly:ly+ny ), intent(out)  glat, real(dp), dimension(lx:lx+nx ,ly:ly+ny ), intent(out)  glon, real(dp), dimension(lx:lx+nx-1,ly:ly+ny-1), intent(out)  garea, real(dp), dimension(lx:lx+nx-1,ly:ly+ny ), intent(out)  dx, real(dp), dimension(lx:lx+nx ,ly:ly+ny-1), intent(out)  dy, real(dp), dimension(lx:lx+nx ,ly:ly+ny ), intent(out)  angle_dx, real(dp), dimension(lx:lx+nx ,ly:ly+ny ), intent(out)  angle_dy, logical, intent(out)  ff  )

private

Use a and k as the parameters of an extended Schmidt-transformed gnomonic (ESG) mapping centered at (plat,plon) and twisted about this center by an azimuth angle of pazi counterclockwise (these angles in radians).

Using the central mapping point as the coordinate origin, set up the grid with central x-spacing delx and y-spacing dely in nondimensional units, (i.e., as if the earth had unit radius) and with the location of the left- lower corner of the grid at center-relative grid index pair, (lx,ly) and with the number of the grid spaces in x and y directions given by nx and ny. (Note that, for a centered rectangular grid lx and ly are negative and, in magnitude, half the values of nx and ny respectively.) Return the latitude and longitude, again, in radians, of the grid pts thus defined in the arrays, glat and glon; return a rectangular array, garea, of dimensions nx-1 by ny-1, that contains the areas of each of the grid cells in nondimensional "steradian" units.

In this version, these grid cell areas are computed by 2D integrating the scalar jacobian of the transformation, using a 4th-order centered scheme. The estimated grid steps, dx and dy, are returned at the grid cell edges, using the same 4th-order scheme to integrate the 1D projected jacobian. The angles, relative to local east and north, are returned respectively as angle_dx and angle_dy at grid cell corners, in radians counterclockwise.

if all goes well, return a .FALSE. failure flag, ff. If, for some reason, it is not possible to complete this task, return the failure flag as .TRUE.

Parameters

[in]	lx	center-relative x grid index for left edge of the domain
[in]	ly	center-relative y grid index for lower edge of the domain
[in]	nx	numbers of the grid spaces in x
[in]	ny	numbers of the grid spaces in y
[in]	a	Extended Schmidt Gnomonic parameter
[in]	k	Extended Schmidt Gnomonic parameter
[in]	plat	latitude of the projection center of the mapping (radians)
[in]	plon	longitude of the projection center of the mapping (radians)
[in]	pazi	azimuth of the orientation of the mapping at its center
[in]	delx	central x-spacing of the grid (radians)
[in]	dely	central y-spacing of the grid (radians)
[out]	glat	grid points' latitudes (radians)
[out]	glon	grid points' longitudes (radians)
[out]	garea	array of grid-cell areas (steradians)
[out]	dx	grid steps in x at grid cell edges (radians)
[out]	dy	grid steps in y at grid cell edges (radians)
[out]	angle_dx	x angles relative to local east (radians)
[out]	angle_dy	y angles relative to local north (radians)
[out]	ff	failure flag

Author

R. J. Purser

Definition at line 1338 of file pesg.f90.

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The documentation for this interface was generated from the following file:

• /scratch1/NCEPDEV/da/George.Gayno/ufs_utils.git/UFS_UTILS/sorc/grid_tools.fd/regional_esg_grid.fd/pesg.f90