Scope of activities
The Glaciers & Sea-level Collaboration Team, first created under Arctic Research Plan 2013-2017 as the Glaciers & Fjords Collaboration Team, will continue operations under Arctic Research Plan 2017-2021. The team's scope of activities will include implementation of Research Objectives and Performance Elements listed under Research Goal 5, which is described as follows in the Plan:
Global mean sea level is estimated to have risen by 1.2 to 1.9 mm per year over the 20th century and that rate rose to 3.0 ± 0.7 mm per year between 1993 and 2010 (Hay et al. 2015). For the period 2003- 2009, roughly 25 percent of the observed sea level rise appears to be due to surface mass imbalance of glaciers, excluding those of coastal Greenland and Antarctica (Gardner et al. 2013). This is similar to the contribution from ice sheets, of which roughly two-thirds is derived from Greenland Ice Sheet mass loss (Shepherd et al. 2012).
The increase in the net rate of ice loss from the Greenland Ice Sheet and other Arctic glaciers and ice caps (land ice) stems from warmer air temperatures that escalate melting on ice surfaces, and warmer ocean temperatures that increase calving of icebergs from marine-terminating glaciers. These forcings also modulate the dynamics of the ice, whose motion is governed by gravity and the constraints of surrounding topography. Although significant progress has been made in describing the current state of land ice, key questions remain about the specific processes that add and remove ice in the Arctic System, particularly regarding the interactions of the ice with the atmosphere and ocean. Given the rapidity with which the Arctic is seen to be warming, much may be learned about the future state of Arctic land ice by studying ongoing processes active in subarctic glacier systems.
As land ice and associated icebergs melt, the resultant effects include: contributions of freshwater and nutrients to the coastal zone with direct effects on marine ecosystems (Wadham et al. 2016) and coastal currents (Marsh et al. 2010); increasing storm-induced flooding associated with the rising sea levels (Tebaldi et al. 2012); reduced deep water formation in the ocean with consequences for climate (Weijer et al. 2012); and altered wind fields on various scales.
These effects, particularly those involving sea level rise and altered coastal currents, have regional and global implications. Regionally, the altered coastal currents will impact transport processes, such as spill response and search and rescue operations. Globally, coastal infrastructure, such as municipal gravity-fed sewage systems, subways, ports, military installations, roads, buildings, and property can be damaged by storm surge.
Present estimates of land ice loss rates and sea level rise rates involve large error bars, indicating the need for expanded observation and improved process understanding to allow enhanced modeling and projection over a variety of spatial and temporal scales. These processes are strongly influenced by the atmosphere above, the adjacent or underlying ocean, and the solid earth below the ice. Consequently, it is necessary to take a systems approach that accounts for atmospheric, oceanographic, and solid earth conditions and processes and that examines the interactions and feedbacks among these components.
The Land Ice and Sea Level Goal focuses on land ice conditions and processes and their consequences. Progress in the implementation of this Goal will also contribute to and benefit from research linkages to other aspects of this Plan. This Goal also addresses the call for policy-driven research that meets fundamental regional and national needs. For example, the changes that are occurring in the Arctic land ice cover affect the well-being of Arctic residents, the functioning of the marine environment, regional and national security, and impact and depend upon processes occurring far beyond the Arctic.
Alaska Science Center (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
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 () 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 () Network, a self-organized, international, open network of scientists, grew out of the U.S. Climate Variability and Predictability () working group. maintains close coordination with of the Study of Environmental Arctic Change () Land-Ice Action Team, whose goals are often commensurate. A 2013 U.S. 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 Land-Ice Action Team met in December 2015 to continue planning for GrIOOS and a report will be released shortly. The 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 ’s Operation IceBridge. International linkages, both directly and through synergies with the newly formed Land Ice/Sea Level Rise Action Team and the expanding activities of the International Network, will be enhanced.