Format description for 24-hour averaged GOES SST Files:

Each file is exactly 6300000 bytes long. Each byte consists of an unsigned integer value which represents a scaled form of the SST at a particular lat/lon location. Henceforth, these will be referred to as “counts”. The lat/lon boundary is 60.00 N southward to 44.95 S and 180.00 W, eastward to 30.05 W. The increment is 0.05 degree in latitude and longitude.

Byte-addressable read should be used to unpack the data from the file. The dimension of the data is INTEGER*1 (3000,2100) where 3000 is the number of longitudes and 2100 is the number of latitudes. The first count read in is at lon = 180.00 W, lat = 60.00 N. Subsequent counts are read eastward across constant latitude lines, at 0.05 degree longitude increments. The eastward-most longitude is 30.05 W. Once all counts for a particular latitude are read, counts are next read eastward across the latitude line 0.05 degrees south of the previous one. This continues until all counts have been read along the longitude range in the southward-most latitude, 44.95 S.

Thus, the INTEGER*1 (3000,2100) array for counts is laid out as follows (in the order read):

(1,1) --> 180.00 W, 60.00 N

(2,1) --> 179.95 W, 60.00 N

…

(2999,1) --> 30.10 W, 60.00 N

(3000,1) --> 30.05 W, 60.00 N

(1,2) --> 180.00 W, 59.95 N

(2,2) --> 179.95 W, 59.95 N

…

(2999,2) --> 30.10 W, 59.95 N

(3000,2) --> 30.05 W, 59.95 N

…

(1,2099) --> 180.00 W, 44.90 S

(2,2099) --> 179.95 W, 44.90 S

…

(2999,2099) --> 30.10 W, 44.90 S

(3000,2099) --> 30.05 W, 44.90 S

(1,2100) --> 180.00 W, 44.95 S

(2,2100) --> 179.95 W, 44.95 S

…

(2999,2100) --> 30.10 W, 44.95 S

(3000,2100) --> 30.05 W, 44.95 S

The SST in Kelvin is generated by multiplying the count by 0.15 and adding it to the baseline value of 270.0 K. Count values of 0, 2 and 4 represent flags, not SST’s so these are not converted to SST (0=space; 2=land; 4=cloud).

The time for each SST observation is obtained from the file name. The file name is of the form sst24o_YYYY_JJJ

where YYYY is the four digit year and JJJ is the day of the year. JJJ is translated to month and day. The hour is set to 12 (since the SST is a 24-hour average), and the minute and second are set to zero.