function perturb_restart(FPATH,MEMBER)

% set parameters
VNAMES={'temp'};
FAC=1e-10; 

% seed random generator
%reset(RandStream.getDefaultStream,MEMBER);
rng(MEMBER);

% open restart file
ncid = netcdf.open(FPATH,'NC_WRITE');

% loop over variables
for vname=VNAMES

% read variable
varid = netcdf.inqVarID(ncid,char(vname));
field = netcdf.getVar(ncid,varid);

% add noise
ind=find(~isnan(field) & field~=0);
for n=1:length(ind) 
  field(ind(n))=field(ind(n))+randn*FAC;
end

% store variable
netcdf.putVar(ncid,varid,field);

% end loop over variables 
end

% close file 
netcdf.close(ncid);

