Run: Polar Stereographic

The COPYGB grid definition parameters for Polar Stereographic grids are listed below:

copygb -g"255 5 NX NY STARTLAT STARTLON 8 CENLON DX DY POLE 64" -x in.grb out.grb

where
	255 5	User-defined Polar Stereographic grid
	NX	Number of points on latitude circle
	NY	Number of points on longitude meridian
	STARTLAT	Southwest corner latitude * 1000 (lat = -90 ... 90)
	STARTLON	Southwest corner longitude * 1000 (lon = -180 ... 180)
	8
	CENLON	Center longitude * 1000
	DX	Longitudinal increment in meters
	DY	Latitudinal increment in meters
	POLE	Northern (0) or southern (128) hemisphere
	64

Please note that all of the grid definition parameters must be integers. All latitude and longitude values are given in thousandths of a degree. The grid increments are given in meters.

User-Defined Polar Stereographic Grid

Again, let's look at the wgrib output for a Polar Stereographic grid and use it to define the grid definition arguments for COPYGB. Run wgrib on a Polar Stereographic dataset:

Here is the grid definition:

polar stereo: Lat1 7.838000 Long1 -141.028000 Orient -105.000000
north pole (65 x 43) Dx 190500 Dy 190500 scan 64 mode 9

Translate this definition to the COPYGB grid specification as follows:

• NX = 65
• NY = 43
• STARTLAT = 7838
• STARTLON = -141028
• CENLON = -105000
• DX = 190500
• DY = 190500
• POLE = 0

Plug these numbers into the grid specification and run COPYGB follows:

Lastly, run wgrib on the COPYGB output and make sure the grid matches the one listed above: