Southern ocean annual climatology
   
Grid:1x1 degree, global, 38 levels from the surface to 5000 m, annual
climatology.
Author: Dirk Olbers of the Alfred Wegner Institute

     This data set is interpolated, based on the validated hydrographic station
data of the Southern Ocean Database at Alfred Wegener Institute, Bremerhaven. 
For interpolation the method of "optimum interpolation" has been used, which is
founded on the least squares method.  The data set contains the parameters
temperature (in situ), salinity and dissolved oxygen on 38 standard levels
resolved on a 1 by 1 degree longitude latitude grid.  

     The following is from the reference below.

      This atlas is based upon a combined data set obtained from several
scientific organizations.  Measurements from about 38,000 hydrographic stations
taken in the Southern Ocean since the beginning of the oceanographic
observations are available.  The largest data sets were provided by the Arctic
and Antarctic Research Institute of Saint Petersburg, Russia, and by the
Lamont-Doherty Geological Observatory, Palisades, USA.  Subsequent
contributions...

     In preparing the data set only those stations were used for which both
temperature and salinity values were known.  No bathythermograph data (XBT or
MBT) were used.  This ensured also a certain degree of the data uniformness. 
The data set is formed using two data types: Nansen cast (bottle) and CTD. 
Bottle data contribute to at least 90% of the whole data set.

     In spite of combining all available historical observations the data set
is still deficient in many ways.  Relatively good station coverage exists only
for a few areas of the ocean.  There is a rapid decrease in the number of
observations with increasing depth.  Observations made during austral summer
clearly prevail.

     The updated picture of the hydrographic structure of the Southern Ocean
presented in this atlas may serve the oceanographic community in many ways and
help unravel the role of this ocean in the global climate system.


Reference:

Olbers,D., Gouretski,V., Seiss, G., Schroeter, J., Hydrographic Atlas of the
     Southern Ocean, Alfred-Wegener-Institut fuer Polar- und Meeresforschung,
     Bremerhaven, 1992.