6. Variables - instructed-glacier-model/igm GitHub Wiki

Whenever this is possible, IGM adopts name convention of PISM. Here is a minimal list of key variables:

Variable names Shape Description Unit
t () Time variable (scalar) y
dt () Time step (scalar) y
x,y (nx) Coordinates vectors m
thk (ny) Ice thickness m
topg (ny,nx) Basal topography (or bedrock) m
usurf (ny,nx) Surface topography m
smb (ny,nx) Surface Mass Balance m/y ice-eq
ubar (ny,nx) x- depth-average velocity of ice m/y
vbar (ny,nx) y- depth-average velocity of ice m/y
U (nz,ny,nx) x-horiz. 3D velocity field of ice m/y
V (nz,ny,nx) y-horiz. 3D velocity field of ice m/y
W (nz,ny,nx) z-vert. 3D velocity field of ice m/y
arrhenius (ny,nx) Arrhenius Factor MPa^(-3) y^(-1)
slidingco (ny,nx) Sliding Coefficient MPa m^(-1/3) y^(-1/3)
divflux (ny,nx) Divergence of the flux m/y
icemask (ny,nx) Mask to restrict the smb comp. -
dtopgdt (ny,nx) Erosion rate m/y
xpos,ypos (nb particles) x,y position of particles m
rhpos (nb particles) rel. pos of particles in ice column m
air_temp (nt,ny,nx) seasonal air temperature 2 m above ground °C
precipitation (nt,ny,nx) seasonal precipitation (water eq) kg m^(-2) y^(-1)