I would like to find 'decadal' climate and ocean data for Europe that I can download and use directly in ArcGIS? Specifically, I am looking for mean annual temperature, sea surface temperature, and salinity raster data for the decades from 1960 onwards.
Most of the available gridded dataset that includes your data is in this list: http://www.esrl.noaa.gov/psd/data/gridded/
You will find a lot of open data using our free Ocean Data tool http://marinexplore.com/explore/
You can select area by location name and narrow selection by polygon tool if need. After previewing data online you will be able to generate a download with CSV file for in-situ measurements and NetCDF file for gridded data.
You could try here University of East Anglia Climate research people They have a mass of data.