%build the surface U from the individual matlab saved decadal means
off=0;
for n=1:36;
n
fil=['PS' num2str(n) '.mat'];
load(['F:\trace\PS\' fil], 'lat','lon', 'PS1');
[NT, NN,N]=size(PS1);

PS(off+1:off+NT, 1:NN, 1:N)=PS1;
NTNT(n)=NT;
clear U1
off=off+NT;
end

save('F:\trace\PS\PS_dec.mat','PS', 'lat', 'lon')