function plotfields( iter )
clear 
clear path 

global Nx Ny Nz
global lat long dz dm mdep
global delt_su su_its t_su delt
global descriptor this_path
global f deltaf Q beta r_expt r_heat H
global time rots it
global g Cp rho_bar alpha
global u v t w
global iterations


for k=1:Nz
k
figure(1)
subplot(2,2,1)
pcolor(squeeze(t(:,:,k)'));shading flat; colorbar; axis square
title(['t timestep ' num2str(eval(it)) ' level ' int2str(k) ]);
drawnow
subplot(2,2,2)
pcolor(squeeze(w(:,:,k)'));shading flat; colorbar; axis square
title(['w timestep ' num2str(eval(it)) ' level ' int2str(k) ]);
drawnow

pause

%subplot(2,2,3)
%pcolor(squeeze((v(:,:,k)'.^2+u(:,:,k)'.^2).^0.5));shading flat; colorbar; axis square
%title(['speed timestep ' num2str(eval(it)) ' level ' int2str(k) ]);
%drawnow
end

return