Scope of activities

GSLCT is focused on observations and model development to better understand changes to land-ice and subsequent impact of these changes on sea level and downstream ecosystems. We continue to discover new ways that glacier ice (and the loss of ice) influences hydrology, ecology and sea level.  The changes in the land-ice system interact with and feedback to other areas of interest to IARPC, including the atmosphere, sea ice, and terrestrial ecosystems.  These interactions occur on a variety of time and space scales, and their consequences are important for enhancing the well-being of Arctic residents, regional and national security, stewardship of the Arctic environment, and the role of the Arctic in the global system.

Team leaders

Shad O'Neel
Alaska Science Center (Website)

Joe MacGregor
NASA Operation IceBridge (Website)

Performance elements from the Arctic research plan

5.1 Coordinate and integrate observations to improve understanding of the processes controlling the mass balance of Arctic land ice.

  • 5.1.1 Maintain support for aircraft and satellite missions that contribute to long-term observations of land ice, including: Landsat-8, ICESat-2, OIB, and the NASA-ISRO Synthetic Aperture Radar (NISAR) mission.
  • 5.1.2 Enable the collection of ground-based observations and associated aircraft measurements documenting variability of land ice on a variety of spatial and temporal scales, including: the Greenland Ice Sheet Monitoring Network (GLISN), the Oceans Melting Greenland (OMG) mission, the U.S. Geological Survey (USGS) Benchmark Glaciers Program in Alaska (and the the Ice2O project in Alaska.
  • 5.1.3 Support investigator-driven studies of land ice process studies across the Arctic, including ocean-glacier interactions, surface and subglacial hydrology, surface mass balance, local surface melt and refreezing, firn densification, glacial isostatic adjustment, iceberg melting, surface energy budget, and related observations.
  • 5.1.4 Enhance national and international communication and collaboration concerning land ice state and processes, for example, through support of the activities of the SEARCH Land Ice Action Team.

5.2 Improve numerical models to enhance projection of ice loss from Arctic land ice and the consequent impact on global sea level, and to better understand the predictability of these processes.

  • 5.2.1 Enable the development and assessment of ice sheet models, both as stand-alone models and within the context of earth system models, including: the Ice Sheet System Model (ISSM), the Community Ice Sheet Model (CISM), the Community Earth System Model (CESM), the Accelerated Climate Modeling for Energy (ACME) project, the Ice Sheet Model Intercomparison Project for CMIP6 (ISMIP6) and the Land Ice Verification and Validation (LIVV) Toolkit.
  • 5.2.2 Develop data sets to be used as boundary and forcing functions for ice sheet, ice cap, and glacier models, including improving regional reanalyses focused on the greater Arctic, improving global reanalysis systems in ways that are relevant to the Arctic, and promoting joint observation-modeling-reanalysis-forecasting activities.
  • 5.2.3 Support investigator-driven modeling projects designed to understand and parameterize important land ice processes, including studies of mélange rheologies and dynamics, wet and dry firn processes, meltwater infiltration and refreezing, interactions between the glacier front and subglacial outflow plumes, and basal sliding laws.


Photo by Jim Pottinger (PolarTREC 2011), Courtesy of ARCUS

Organized to enhance interagency collaborations on land ice loss process studies targeting specific dynamic regimes, under Arctic Research Plan 2013-2017 the Glaciers & Fjords Collaboration Team continued to encourage discussion on a variety of glaciological processes and parameterizations in models.

The Community Earth System Model (CESM) Land Ice Working Group continues to facilitate collaboration between agencies and academic scientists to develop a community ice sheet model, which incorporates the results of recent process studies, for use in Earth system models. The Ice Sheet Model Project (ISMIP6) has been formally endorsed by the Coupled Model Intercomparison Project (CMIP) Phase 6, and allows for ice sheets to be, for the first time, included in the CMIP definition of Earth System modeling. ISMIP6 experiments and data request protocols have been submitted for a publication. The suite of experiments designed to investigate the uncertainty in sea level due to ice sheet model initialization in standalone mode (i.e.: uncoupled to climate models) has been completed for the Greenland ice sheet by 15 international groups.  

The International Greenland Ice Sheet-Ocean Interactions (GRISO) Network, a self-organized, international, open network of scientists, grew out of the U.S. Climate Variability and Predictability (CLIVAR) working group. GRISO maintains close coordination with of the Study of Environmental Arctic Change (SEARCH) Land-Ice Action Team, whose goals are often commensurate. A 2013 U.S. CLIVAR workshop recommended a planning strategy for obtaining long-term time series of critical in situ glaciological, oceanographic, and atmospheric parameters to provide information on the time-evolving relationships between different climate forcings and the glacier flow, called the Greenland Ice-Ocean Observing System (GrIOOS). The SEARCH Land-Ice Action Team met in December 2015 to continue planning for GrIOOS and a report will be released shortly. The GRISO Network has been funded to develop a virtual data portal, leveraging existing infrastructure, to make interdisciplinary data submission and data availability easier and to promote uniform and appropriate data management practices.  

Priorities for 2017

The activities of the team will be subsumed under those of the team addressing Research to Understand and Project the Mass Budget of Glaciers, Ice Caps, and the Greenland Ice Sheet, and Their Consequences for Sea Level Rise in Arctic Research Plan 2017-2021. Long-term monitoring of the Greenland ice sheet and its glaciers will continue through NASA’s Operation IceBridge. International linkages, both directly and through synergies with the newly formed SEARCH Land Ice/Sea Level Rise Action Team and the expanding activities of the International GRISO Network, will be enhanced.

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