feb0m.ps, aug0m.ps GMT maps of PO4 distributions at sea surface.
dif0m.ps : PO4 seasonal difference at sea surface (August - February)
po4mapnew.dat.gz : PO4 3D fields (12 months, 0 to 75 m). The file is compressed
by command gzip. To uncompress it, use "gunzip".
readmap.f : fortran program to read the map.
The file is on a regular 2deg per 2deg grid. First latitude is 90N , first
longitude is Greenwitch,
The standard levels of Levitus from 0 to 75 m are :
0, 10, 20, 30, 50, 75
File nutrient-doc contains all information about the creation of monthly maps.