dset ^wymidx-jjas.dat undef -99999 options little_endian Title Webster and Yang Monsoon Index jjas xdef 1 linear 0.0 2.5 ydef 1 linear 0.0 2.5 tdef 72 linear 00Z01Jan1948 1yr zdef 1 levels 850 vars 1 idx 1 0 Monsoon Index using 850hPa wind data ENDVARS