ISMIP6 Model Viewer

What is this?

This is a visualization tool for exploring and comparing model outputs from the Ice Sheet Model Inter-comparison Project for CMIP6 (ISMIP6). ISMIP is an international collaborative effort to compare the behavior of ice sheet models under a standardized set of experiments. This tool is not affiliated with ISMIP – it’s just a visualizer of publicly-available ISMIP6 outputs, which are hosted here on source.coop.

The tool is a prototype article for a larger push we’re working on to build backend infrastructure for model-data comparisons. If you’re interested in that, feel free to check back here as we add more information or reach out to either shane.grigsby@astera.org or thomas.teisberg@astera.org.

We hope this tool is useful and interesting to the scientific community. If you find it useful or you find issues, we encourage you to email us or open an issue.

More about ISMIP6 and the context behind these models

This tool visualizes only model outputs from the ISMIP6 Antarctica ensemble for now. The general structure of those experiments is described on the ISMIP6 wiki. For details, please read the ISMIP6 Antarctica results paper in The Cryosphere.

Open Source

This tool is open source, and consists of two components: a front end viewer, and a back-end connection to the virtualized dataset. Both of these components are client side and run fully within your browser. Visit the ismip-viewer repository to contribute or report issues related to the viewer, or the icechunk-js library to contribute or report issues to the icechunk client.

Getting started

Feel free to play around with the dedicated viewer where you can add panels to compare models or experiments side-by-side, or just explore a single dataset at a time. The viewer panels are embeddable using MyST and Quarto (or directly using an iframe); we’ve done that below with a few example comparisons we think are interesting.

Subglacial temperature

  • Variable: litempbotgr – Basal temperature beneath grounded ice sheet (K)
  • Models: AWI/PISM1, DOE/MALI, LSCE/GRISLI2, NCAR/CISM
  • Experiment: exp05

There are few direct measurements of the temperature profile within or beneath ice sheets. As a result, basal temperature (temperature at the ice-bedrock interface) is poorly constrained. Models resolve a wide range of temperatures, ranging from deeply frozen to at or near the pressure melting point.

For an accessible introduction to this topic, see Bethan Davies’ page on glacier thermal regimes.

Grounding line retreat and sub-ice shelf melt

  • Variable: libmassbffl – Basal mass balance flux beneath floating ice (kg m-2 s-1)
  • Model: DOE/MALI
  • Experiments: exp05, exp07

libmassbffl shows the melt rates under floating ice shelves. It’s a good way to look at a major component of Antarctic mass loss and also visualize grounding line retreat. Experiments 5 and 7 represent the same assumptions but with different climate forcings. exp05 is a high-emissions scenario (RCP 8.5) while exp07 is a low-emission scenario (RCP 2.6).

This is a good comparison to zoom in on, play with the time slider to see how grounding lines evolve over time, and to use the color scale options as needed.

For an accessible introduction to this topic, see Bethan Davies’ pages on grounding lines and ice shelves.

Surface mass balance

  • Variable: acabf – Surface mass balance flux (kg m-2 s-1)
  • Models: DOE/MALI, AWI/PISM1
  • Experiments: exp05, exp07

Surface mass balance refers to the net accumulation and ablation occurring at the surface of an ice sheet. In most of Antarctica, this primarily means “how much snow is falling?” Antarctica is huge, so small differences in snowfall over big areas can make an enormous difference. Patterns of surface mass balance change over time and vary with the selected climate forcing, so be sure to explore the time slider and look at differences between the low-emission (exp07) and high-emissions (exp05) experiments.

For an accessible introduction to this topic, see Bethan Davies’ page on Antarctic Ice Sheet mass balance.