X axis: whole world in 360 1.00° steps, first point at 0.50° E, last point at 359.50° E
Y axis: regular grid with 180 1.00° steps, first point at 89.50° S, last point at 89.50° N

Monthly data available from Jan2003 to Dec2017 ( 180 months)
Variable lwe_thickness (monthly mean of daily Liquid_Water_Equivalent_Thickness) in cm
Full metadata.

Get grid points, average area or generate subset

Mask:	no mask mask1.txt mask5.txt   add a mask to the list
Latitude:	°N - °N
Longitude:	°E - °E
Boundaries:	halfway grid points interpolated
Make:	average max min set of grid points subset of the field
Demand at least:	% valid points in this region

Create a field with lower time resolution

New time scale:	annual (Jul-Jun) annual (Jan-Dec) biannual seasonal
New variable:	mean sd sum sum above sum below number min time of min max time of max first time last time of LWE
Threshold:	no cut less than greater than cm percentile normal 1971-2000
Minimum:	% valid data
First apply:	-month running mean
Missing data:	ignore, climatology, trend, persistence.

Create a field with lower spatial resolution

Average over blocks of longitude and latitude grid cells

getfieldtype: please ask me to add "lwe_thickness" to the lists in getfieldtype

Construct a statistical forecast model from this field

Please consider downloading this field from the authoritative site.
If you really want to get it here, GRACE LWE is available as a netcdf file (size 15.6357 MB).