r (height data): 
%     hs.CData = Z(:,:,k); 
%     
%     % Get anti-aliased U and V: 
%     tmpu = interp2(Lon,Lat,filt2(U(:,:,k),1,skip*2,'lp'),Lonf,Latf); 
%     tmpv = interp2(Lon,Lat,filt2(V(:,:,k),1,skip*2,'lp'),Lonf,Latf); 
%     tmpu(land) = nan; 
% 
%     % Update quiver arrows: 
%     q.UData = tmpu; 
%     q.VData = tmpv; 
%     
%     txt.Color=col(k,:); 
%     axis(ax) % ensures axis limits match in every frame
%     gif % writes this frame
%  end
% 
%% 
% 
% <<../markdown_figures/tmd_logo_v2.