||CARS2006 spans the southern 2/3 of the worlds oceans, from 70S to 26N, except in the Atlantic where is reaches only to 10N. The six water properties mapped in are temperature, salinity, oxygen, nitrate, silicate, phosphate. It comprises historic mean fields and average seasonal cycles, derived from all available historical subsurface ocean property measurements (primarily research vessel instrument casts and autonomous profiling buoys.)
CARS does not provide information for any given year. CARS is created by averaging/interpolating all available oceanographic cast data, most of which was collected in the last 50 years. Especially when trying to provide an estimate at every location and every depth in the worlds oceans, there is not enough data to resolve any one year, so we ignore the year of collection of each observation and retain only the day-of-year - and then fit a mean and mean-seasonal-cycle at each point.