Most GFDL data is stored on 48x40 (R15 runs) or 96x80 (R30 runs)
In the original data as received from GFDL the data points are ordered
beginning at the southern most latitude and at 0 longitude.
Assuming the points are read into a two dimensional array in
order, the resulting layout is:

 R15

  As I = 1 to 48 , Longitude goes 0 to 352.5E, eastward increments of 7.5.
  As J = 1 to 40 , Latitude starts at the southern most
		   Gaussian latitude, SH latitudes given below.

	     1 -86.5980
	     2 -82.1909
	     3 -77.7578
	     4 -73.3188
	     5 -68.8776
	     6 -64.4353
	     7 -59.9925
	     8 -55.5492
	     9 -51.1057
	    10 -46.6620
	    11 -42.2183
	    12 -37.7744
	    13 -33.3305
	    14 -28.8865
	    15 -24.4425
	    16 -19.9984
	    17 -15.5543
	    18 -11.1102
	    19 - 6.6662
	    20 - 2.2220

  In many applications, DSS uses an approximation of this Gaussian
  distribution defined by a southern most latitude of -86.658 and
  a latitude increment of 4.444.


 R30

  As I = 1 to 96 , Longitude goes 0 to 356.25E, eastward increments of 3.75.
  As J = 1 to 80 , Latitude starts at the southern most
		   Gaussian latitude, SH latitudes given below.

	     1 -88.2883
	     2 -86.0711
	     3 -83.8407
	     4 -81.6074
	     5 -79.3730
	     6 -77.1380
	     7 -74.9027
	     8 -72.6673
	     9 -70.4317
	    10 -68.1960
	    11 -65.9603
	    12 -63.7245
	    13 -61.4886
	    14 -59.2528
	    15 -57.0169
	    16 -54.7810
	    17 -52.5451
	    18 -50.3092
	    19 -48.0733
	    20 -45.8374
	    21 -43.6014
	    22 -41.3655
	    23 -39.1295
	    24 -36.8936
	    25 -34.6576
	    26 -32.4217
	    27 -30.1857
	    28 -27.9497
	    29 -25.7138
	    30 -23.4778
	    31 -21.2418
	    32 -19.0058
	    33 -16.7699
	    34 -14.5339
	    35 -12.2979
	    36 -10.0619
	    37 - 7.8259
	    38 - 5.5899
	    39 - 3.3540
	    40 - 1.1180

  In many applications, DSS uses an approximation of this Gaussian
  distribution defined by a southern most latitude of -88.322 and
  a latitude increment of 2.236.