Each files contains 12 monthly mean for each year 1991 to 2100:
Sea Surface Temperature (actually 0-10m mean) (SST, degC)
Sea Surface Salinity (actually 0-10m mean) (SSS, psu)
Surface incident photosynthetically available radiation (PAR, uEin/m2/s)
Nitrate concentration (0-10m), (NO3, mmol N/m3)
Phosphate concentration (0-10m), (PO4, mmol P/m3)
Iron concentration (0-10m), (Fe, mmol Fe/m3)
Silicic acid (0-10m), (SiO2, mmol Si/m3)
Note that the atmospheric-ocean component of the earth system model used to produce the forcing fields has its own internal interannual variability. Though the frequency of phenomena such as ENSO are captured, they do not occur in same years as the real ocean
The model output list here was used in:
Bardon, L., B.A. Ward, S. Dutkiewicz, and B.B. Cael. Testing the skill of a species distribution model in a virtual environment. Geophysical Research Letters, in press.