How to reverse the latitudes while saving a variable in an nc file

I am trying to save the variable curl into an nc file. But when the file is saved it is reversed on the latitudinal dimension. Meaning, the variable curl is saved as a mirror image of itself (mirrored on the equatorial plane). This is the code that I have used to save the variable. Please help me understand where I am going wrong.

    nccreate('curl_mat.nc', 'longitude','Dimensions',{'longitude' length(lonx)});
    nccreate('curl_mat.nc', 'latitude','Dimensions',{'latitude' length(latx)});
    nccreate('curl_mat.nc', 'time','Dimensions',{'time' length(tnew)});
    nccreate('curl_mat.nc', 'curl', 'Dimensions',{'longitude' length(lonx) 'latitude' length(latx) 'time' length(tnew)});
    
    
    ncwrite('curl_mat.nc', 'time', tnew);
    ncwriteatt( 'curl_mat.nc', 'time', 'units', ...
          'days since 1950-01-01 00:00:00' );
    
    ncwrite('curl_mat.nc', 'longitude', lonx);
    ncwriteatt( 'curl_mat.nc', 'longitude', 'units', 'degrees east');
    
    ncwrite('curl_mat.nc', 'latitude', latx);
    ncwriteatt( 'curl_mat.nc', 'latitude', 'units', 'degrees north');


    ncwrite('curl_mat.nc', 'curl', curl);
    ncwriteatt('curl_mat.nc', 'curl' , 'units', 'N/m3');