Ice-shelf surface, basal and bedrock topography data for the second Ice Shelf-Ocean Model Intercomparison Project (ISOMIP+)

• Main Authors: Cornford, Stephen, Asay-Davis, Xylar
• Format: Dataset
• Language: English
• Published: GFZ Data Services 2016
• Subjects: ice sheet-ocean interactions; ice shelves; ice shelf cavities; idealized modeling; Ice Sheet; Ice Shelf; Ice Shelves
• Online Access: https://doi.org/10.5880/PIK.2016.002

Abstract This data set includes four sets of ice-shelf topography data for use in the ISOMIP+ experiments described in Sec. 3 of Asay-Davis et al. (2015), to which this data set is supplementary material. The data set contains four NetCDF files, each of which includes six spatially two-dimensional fields: the ice upper surface, ice draft (ice sheet lower surface), bed topography, the fraction of open ocean, the fraction of floating ice and the fraction of grounded ice. Methods Methods: The topographic data was produced using subversion revision number r2825 of the BISICLES ice-sheet model (https://commons.lbl.gov/display/bisicles/BISICLES) configured to use the shallow shelf approximation (SSA, a commonly used approximation of the Stokes equation appropriate for ice shelves and fast flowing ice streams). The simulation used to produce the topography was the Ice1r followed by the Ice1ra experiment, as described in Sec. 2.2 of Asay-Davis et al. (2015). The bedrock topography for the experiment is described by an analytic function in Sec. 2.1 of Asay-Davis et al. (2015). In these experiments, BISICLES was first run to steady state without basal melting, then was allowed to retreat for 100 years forced by a basal melt parameterization (Ice1r) and finally was allowed to re-advance for 100 years with the melt parameterization turned off (Ice1ra). BISICLES makes use of adaptive mesh refinement (AMR) to focus resolution in fast flowing regions and near grounding lines. In the simulations, resolution was allowed to vary from 4 km to 1 km, and the topographic snapshots have been interpolated to simple rectangular mesh with a constant resolution of 1 km. TableOfContents List of datasets included in this data publication: Ocean1_input_geom_v1.01.nc: Topography data from the beginning of the Ice1r experiment, the topographic boundary conditions for the Ocean0 and Ocean1 experiments. Ocean2_input_geom_v1.01.nc: Topography data from the end of the Ice1r experiment (year 100), the topographic boundary conditions for the Ocean2 experiment. Ocean3_input_geom_v1.01.nc: 101 yearly snapshots of the topography data from the Ice1r experiment (years 0 to 100), the topographic boundary conditions for the Ocean3 experiment. Ocean4_input_geom_v1.01.nc: 101 yearly snapshots of the topography data from the Ice1ra experiment (years 100 to 200), the topographic boundary conditions for the Ocean4 experiment. inputs.spin: Configuration file for the initial BISICLES spinup to steady state without melting inputs.melt: Configuration files for the Ice1r and Ice1ra evolution shortshallow.py: Python script for computing the melt parameterization in the Ice1r and Ice1ra experiments. addMasksToBisicles.py: Python script use to compute the floating, grounded and open ocean fractions based on the topography data and the assumption of exact flotation of the ice shelf.