;
; field1='U'
; field2='V'
; winds=['PSFC','tk']
;

if ((winds(0) eq 'PSFC') $
	and (winds(1) eq 'tk') $
	and (field1 eq 'U') $
	and (field2 eq 'V')) then begin


print, 'computing wind stress'

title='Wind stress (!NN!N.m!U-2!N)'

temp=overvector_y
press=overvector_x
gasconst=192.
rho=press/(gasconst*temp)

vonkar=0.4
heightlay=5.66  ;; a calculer ??
roughness=0.01
cd=vonkar/(alog(heightlay/roughness))
cd=cd^2

velocity2=what_I_plot^2 + overcontour^2

stress=rho*cd*velocity2
what_I_plot=stress

;;overcontour=-10.*alog(overvector_x/610.)
overcontour=overvector_x

overvector_x=0
overvector_y=0

;;tmpfield=reform(u[*,*,0,*])
;;press_bg = total(tmpfield,3)/n_elements(tmpfield(0,0,*))
;;overcontour=press_bg


endif