% NOAA Optimum Interpolation (OI) Sea Surface Temperature (SST) V2
% Coverage GLOBAL, period 1854-2004
% Further reference on this data product are found at:
% http://www.cdc.noaa.gov/cdc/data.noaa.oisst.v2.html

% load data
load NOAA_SST.mat

% list what is in the file
who

%  LAND_MASK     180x89          128160  double array
%  LAT           180x89          128160  double array
%  LON           180x89          128160  double array
%  MONTH        1812x1            14496  double array
%  SST           180x89x1812  232225920  double array
%  YEAR         1812x1            14496  double array


% example: plot the SST for Jannuary 2002
time_index = find (YEAR == 2002 & MONTH == 1);

pcolor(LON,LAT, SST(:,:,time_index).*LAND_MASK);
shading flat; colorbar


% compute monthly means
for imon = 1:12
   in = find( MONTH == imon);
   SST_Monthly(:,:,imon) = mean(SST(:,:,in),3);
end
   
% compute anomalies from monthly means
SSTa=zeros(size(SST));
for it=1: length(YEAR)
   imon = MONTH(it);
   SSTa(:,:,it) = SST(:,:,it) - SST_Monthly(:,:,imon);
end