6.2. Initial conditions
6.2.1. Topography
The initial conditions for the ice topography can be chosen in the run-specs headers by the parameter ANF_DAT
(“ANF”
being a remaining Germanicism in the code, derived from the German word “Anfang” = start, beginning, initial):
1
: Present-day initial topography.2
: Ice-free initial topography with relaxed lithosphere.3
: Initial values from previous simulation.
For specifying the topography files, see Section “Model domain, grid and time/Topography”.
6.2.2. Temparature
In case of ANF_DAT = 1
, initial conditions for the 3D temperature field must also be prescribed. This is done by the parameter TEMP_INIT
:
1
: Constant value in the entire ice sheet (defined by parameterTEMP_INIT_VAL
).2
: In each ice column equal to the local ice surface temperature.3
: Ice temperature linearly increasing with depth.4
: Ice-temperature profiles from analytical solution for 1D steady-state advection-diffusion equation under the assumption of linearly varying \(v_z\) (Robin [56] solution).5
: Ice temperature from previous simulation.
The settings ANF_DAT = 3
, or ANF_DAT = 1
and TEMP_INIT = 5
, require specifying an initial-value file, which is typically a time-slice output file from a previous simulation (see Section “Output files”). This is done by assigning the parameter ANFDATNAME
a text string with the file name. In addition, the path where this file is located must be given as an option -a /path/to/initial/value/directory
to the script sico.sh
when running SICOPOLIS (see Section “How to run a simulation”).