'espesor500=z(lev=500)-z(lev=1000)'
'at=6371221'
'w=7.29E-5'
'pi=3.1415926'
'f=2*w*sin(lat*pi/180)'
'dx=at*cos(lat*pi/180)*cdiff(lon,x)*pi/180'
'dy=at*cdiff(lat,y)*pi/180'
'ut=-(1/f)*cdiff(espesor500,y)/dy'
'vt=(1/f)*cdiff(espesor500,x)/dx'
'clear'
'set gxout shaded'
'set lev 500'
'd t'
'set gxout contour'
'set ccolor 0'
'd espesor500'