Observational datasets collected for ISMIP7 Antarctic experiments: bed and surface topography, drainage basins, ocean climatologies, and ice-front and calving observations. Provided as a convenience for ice-sheet modellers rather than as part of the ISMIP7 protocol. Each dataset is third-party, with its own citation and licence — see the per-dataset attribution in the product README. The ISMIP7 protocol refers to this collection as the Observational MIPkit.
The files provided contain part of the dataset generated for the submitted manuscript, “Empirical constraints on ice-cliff calving.” (preprint). The dataset includes ice front positions, velocities, and cliff heights for four glaciers where we observed ice cliff heights above 90 m using ICESat-2 and that undergo ice-front retreat from 2019-2023.
These observations include four glaciers where the calving of tall cliffs resulted in rapid but short-lived retreat. Eventually, all cliffs subsequently advanced, during which dynamic thinning either rapidly reduced the cliff height, or the cliffs re-advanced with little/no change in height. Contrary to existing parameterizations of MICI, calving rates did not always monotonically increase with cliff height, even after very tall cliffs formed and retreat into thicker ice occurred. Nonetheless, the data should be useful to calibrate calving rates in locations where tall cliffs retreat rapidly.
Frost Glacier, East Antarctica
Fleming Glacier, Antarctic Peninsula
Commandant Charcot Glacier, East Antarctica
Tuttulikassaap Sermia (Hayes Glacier), Greenland
Each folder (labeled by glacier name) contains a shapefile of the ice front positions over the survey period. Each shapefile contains two columns:
'id': the date of the ice front trace in YYYYMMDD
'geometry': a linestring of the ice front in x,y polar stereographic coordinates (EPSG 3031/3413)
Each folder (labeled by glacier name) contains netcdf files with velocity data generated using auto-RIFT (Gardner et al., 2018) and provided by the NASA MEaSUREs ITS_LIVE project, cropped to the glacier area.
'v': mean annual velocity (m/y)
'x': x-coordinate (EPSG 3031/3413)
'y': y-coordinate (EPSG 3031/3413)
This folder contains a .csv file for each glacier. Ice cliff coordinates and heights were collected by ICESat-2 and are therefore point (not gridded) data.
'x': x-coordinate of ice cliff (EPSG 3031/3413)
'y': y-coordinate of ice cliff(EPSG 3031/3413)
'cliff_height': elevation of ice cliff above the waterline (m)
'date': date of ice cliff measurement (YYYY-MM-DD)