The following is metadata information for an archive of numerical ice-sheet
model output shown in Figure 6 of the paper:

  Possible Role for Tectonics in the Evolving Stability of the Greenland Ice 
  Sheet (2019). R.B. Alley, D. Pollard, B.R. Parizek, S. Anandakrishnan,
  M. Pourpoint, N.T. Stevens, J.A. MacGregor, K. Christianson, A. Muto, 
  and N. Holschuh. Journal of Geophysical Research-Earth Surface, in review.

The output is from simulations of the Greenland Ice Sheet with the Penn State 
3-D ice-sheet model, run for 10,000 years to near equilibrium starting from 
modern conditions. There are 2 files for each simulation:

  fort.92.nc  
     Netcdf-format file with 2-D maps of selected variables at regular time 
     intervals through a run. The main variables are:
     alatd, alond    latitudes and longitudes at grid centers.
     h               ice thickness.
     hs              surface elevation (ice, land, or ocean).
     hb              bedrock elevation.
     utop, vtop      surface ice velocities (in eastward, northward directions).
     maskwater       0 if grounded ice or land, 1 if floating ice or ocean.
     time            model years (the final model state at year 10,000 is 
                     shown in Fig. 6 of the paper).

  fort.22
     Tabular ascii files with time series of overall quantities indicated
     in the header, including:
     time = model year
     toti = total ice volume (cubic km)
     totig = total grounded ice volume (cubic km)
     totif = total floating ice volume (cubic km)
     tota = total ice area (square km)
     totag = total grounded ice area (square km)
     totaf = total floating ice area (square km)
     h(m)  = average ice thickness (m)
     eof(m) = equivalent global sea level change contained in the ice (m)

Each sub-directory contains these files for one simulation. The simulations 
are for various degrees of surface air warming above modern, and for 
3 different configurations of basal sliding coefficients, as indicated by the 
subdirectory names:

  Run_[C,D]-<mm>_T<nn>

where 
  nn is -2,0,2,4 or 6, the surface air warming in degrees C.

  mm is -20 or -6, the exponent in the basal sliding configuration, 
                   with -20 = no perturbation, -6 = slippery base.

  C or D indicates whether the basal-sliding perturbation is applied 
                   everywhere (C), or only northward of 70 N (D).

For instance, the simulation in Run_C-6-T2 has slippery base applied 
                   everywhere, and +2 degrees C of surface air warming. 

There are no Run_D-20_T* runs, which would be identical to Run_C-20_T*.
                      
The dataset consists of 15 subdirectories as above, and the read-me
file README_ALLEYETAL2019.txt (this file).