Variables
In general, IGM adopts name convention of PISM. Variable names serves to identify when outputing them, or in the code, they can be accessed (read and write) by state.varname. 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 | \(m~y^{-1}\) ice-eq |
| ubar | (ny,nx) | x- depth-average velocity of ice | \(m~y^{-1}\) |
| vbar | (ny,nx) | y- depth-average velocity of ice | \(m~y^{-1}\) |
| U | (nz,ny,nx) | x-horiz. 3D velocity field of ice | \(m~y^{-1}\) |
| V | (nz,ny,nx) | y-horiz. 3D velocity field of ice | \(m~y^{-1}\) |
| W | (nz,ny,nx) | z-vert. 3D velocity field of ice | \(m~y^{-1}\) |
| 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 | \(m~y^{-1}\) |
| icemask | (ny,nx) | Mask to restrict the smb comp. | - |
| dtopgdt | (ny,nx) | Erosion rate | \(m~y^{-1}\) |
| 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) | \(kg~m^{-2}~y^{-1}\) |