'set lev 1000 200'

'W=7.292E-5'

'G=9.80616'

'AT=6371221.3'

'DEG2RAD=3.141592654/180'

'F=2*W*SIN(lat*DEG2RAD)'

'DX=AT*COS(LAT*DEG2RAD)*CDIFF(LON,X)*DEG2RAD'

'DY=AT*CDIFF(LAT,Y)*DEG2RAD'

'UG=-G/F*CDIFF(Z,Y)/DY'

'VG= G/F*CDIFF(Z,X)/DX'

'div=hdivg(u,v)'

'divg=hdivg(ug,vg)'

'un=u-ug'

'vn=v-vg'

'divn=hdivg(un,vn)'

'clear'

'set lev 500'

'set gxout shaded'