US Climate Variability and Predictability Program

Greenland Ice Sheet/Ocean Working Group Report

Woods Hole Oceanographic Institution
Growing evidence suggests that a significant part of the recent mass loss from the Greenland Ice Sheet was triggered by changes at the marine margins of its outlet glaciers. The relevant dynamics and thermodynamics at the ice/ocean interface are complex and poorly understood making it challenging to understand the ongoing changes and include the appropriate physics in ice sheet and earth systems model. A parallel issue is the increasing release of freshwater from the Greenland Ice Sheet into the Atlantic. Ice/Ocean interaction processes determine both the timing and location of the freshwater export pathways.

The US CLIVAR Working Group on Greenland Ice Sheet/Ocean Interactions, consisting of oceanographers, glaciologists, glacial hydrologists and atmospheric scientists (including observationalists and modelers), began working together in 2011 with the goal of promoting interaction amongst the diverse communities interested in this problem. Specific objectives were to summarize the state of knowledge, identify the most pressing questions and make specific recommendations on how to move forward. They have been achieved through a series of steps including:

1) A white paper (eventually a BAMS article) summarizing the state of knowledge (Straneo et al. 2012; Straneo et al. 2013).
2) An open workshop on Greenland Ice Sheet/Ocean Interactions held in Beverly, MA in June 2013, ~100 scientists (including many early career) and U.S. program managers.
3) A workshop report synthesizing research priorities and making specific recommendations on how to move forward (Heimbach et al. 2014).
4) A townhall meeting organized by NSF, AGU 2013, to discuss the report recommendations.
5) US CLIVAR Variations Newsletter Spring 2014 (Eds Heimbach, Straneo, Sergienko)

The US CLIVAR Working Group as such is now at the end of its term. Following the success and interest expressed by the international community, we are in the process of assembling an international working group, GRISO, focused on promoting progress on two of the top priorities identified in the report: 1) Integrated field and modeling experiments to be conducted at several megasites; 2) establishment of a long-term observing system for Greenland Ice/Ocean interactions.
We have been discussing how this working group may fit under CliC and CLIVAR activities.
Abstract file
Presentation file