dset ^extAll.gr
undef -999.0
title sio_2016_mask.dat
options little_endian
ydef 1 linear 0 1
xdef 1 linear 0 1
zdef 20 linear 1 1
tdef 9 linear 1Aug2018 1mo
vars 4
extNH      20 1,0,0  NH Extent using all points
extNH2     20 1,0,0  NH Extent using points north of jcrt
extAK      20 1,0,0  AK Extent using all points
extAKmax   20 1,0,0  AK maximup possible Extent using all points
ENDVARS