Summaries of Workshop Panels and Breakout Discussions
STAKEHOLDERS
The workshop began with a panel discussion on stakeholder needs and key information gaps that could be addressed to help inform the decision-making process. Understanding stakeholder needs is an important step in defining the problem (asking the right questions) and developing solutions. Gary Hufford from the National Oceanic and Atmospheric Administration/ National Weather Service (NOAA/NWS) gave an overview of some of the recent gaps and needs of the Alaska Region NWS program. These include ice coverage and extent needed for crab fishing in the Bering Sea, ice recession time and extent needed for commercial activities, and ice conditions for the safety of subsistence hunters. He noted that there are specific types of information needed to better understand sea ice conditions including seasonal and longer freeze-up and recession times, ice extent, definitive ice type, ice thickness, ice shape, optimized observations, and improved coupled models. Vera Metcalf of the Eskimo Walrus Commission also emphasized that understanding sea ice conditions is critically important for subsistence hunters. They must take a variety of factors into consideration during hunting (which includes towing the mammals onto the ice) and also for their safety. These factors include wind direction and weather, ocean currents, the existence of icebergs, and the thickness of ice.
The US Coast Guard places a great deal of importance on safety in this region, as noted by LCDR Ken Boda. In addition to safety, he emphasized the importance of security (national and economic), stewardship (to protect natural resources and promote science), and operational planning for the future. In terms of seasonal capabilities, the Coast Guard needs to know the timing of sea ice advance and retreat, capabilities for ships, and the footprint of the ice. Understanding what to expect from sea ice on a decadal scale is also important to plan for icebreaking capability and infrastructure in the future. Capt. Michael Terminel from Edison Chouest Offshore pointed out that increasing interest in natural resources is awakening the Arctic region for a number of industry stakeholders. He demonstrated the importance of forecasting weather conditions, and indicated that satellite and radar imagery is a key factor in tracking ice ridges and multiyear ice (this has
implications for ship navigation). Like Metcalf, he also noted the critical importance of wind and ocean currents in driving ice conditions.
OBSERVATIONS
During a discussion on key gaps and challenges in observations for future sea ice prediction, Hajo Eicken of the University of Alaska Fairbanks noted a number of gaps in our current understanding of sea ice. These observational challenges include predicting the seasonal decay of ice and heat fluxes over decaying ice. He indicated that when interacting with the modeling community, the decadal timescale is very important, and snow on sea ice is a particularly relevant factor on this scale. He also mentioned that it is important to accurately define the questions that stakeholders would like answered (while also acknowledging that different stakeholders have different needs). He indicated that a path forward may be to define the sea ice services that stakeholders require, translate those needs into specific prognostic variables, and determine the predictive success that is acceptable to the stakeholders.
Walt Meier of the National Snow and Ice Data Center also emphasized the importance of filling gaps in observations, although he pointed out a number of products that are already available for ice extent and concentration, ice thickness, and ice motion. Some current limitations include quantitative error estimates, the harmonization of spatial and temporal scales, melt state and albedo, snow depth, information on ice deformation, in situ and airborne measurements, integrated products, and data access. He also mentioned the importance of continuity and contingency plans in satellite missions (to avoid large gaps in data availability). Ron Lindsay of the University of Washington discussed the importance of in-depth conversations between stakeholders and researchers. This is essential, not only to be sure that we are getting the observations that we actually need, but also to determine where some possible improvements in skill would most help the stakeholders. He noted that, using this information, we can begin to focus on those problems that we can more readily solve and would also be most helpful (instead of using this time on questions that have a limited likelihood of being solved, or on issues that are of limited importance to stakeholders).
Following the panel discussion, members of the breakout groups convened to address additional challenges and strategies associated with sea ice observations. Breakout group rapporteurs mentioned that there is a wide range of needs on many spatial and temporal scales, and that key parameters should be clearly defined depending on stakeholder needs. One group suggested that there are linkages between the need for specific ice parameters and broader scale questions such as: Is there ice? What is it like? Where is it going? This helps to drive observational needs for defining ice extent, ice character, and ice motion. Other issues that were discussed in the breakout groups include quantifying uncertainty, assimilating observations into models, improving bathymetry data, the
need for long-term and sustained observations, contingency plans for satellite systems, and better coordination within the modeling, observational, and stakeholder communities.
MODELING
The modeling panel discussion focused on the challenges in modeling and ways to improve interaction with the observational community. Cecilia Bitz of the University of Washington suggested that trying to initialize a model based entirely on observations is a current gap in our understanding. Fully coupled numerical and statistical models will need to be used for prediction, and observations are needed for initial conditions and validation of predictions. She indicated that an important path forward is to communicate the limits of predictability to stakeholders and others, and to use models to determine the most needed measurements. A focus on the coupling between ice, atmosphere, and the ocean was discussed by Elizabeth Hunke from Los Alamos National Laboratory. She indicated that better observations are needed (particularly snow on ice) to continue to make model improvements. She also noted that sea ice predictability is critically dependent on the predictability of the applied forcing and the ice equilibrium state associated with the applied forcing. The strength of feedbacks (including atmosphere and ocean fluxes) needs to be better understood.
Andrey Proshutinsky from the Woods Hole Oceanographic Institution commented on the oceans role in sea ice changes (including three components of influence: atmospheric circulation changes, heat release and ice melt, and sea ice dynamics). He noted that the modeling challenges include reanalysis and reconstruction of sea ice and ocean conditions, implementation of high-resolution models, climate and process studies based on modeling, and systematic model calibration and validation. Possible advances in modeling could address these issues. Examples include increased model resolution, development of a landfast ice model, inclusion of tidal and atmospheric pressure forcing, and improvements of data assimilation methods. Like many of the other panelists, he also mentioned the importance of collaboration with the observational community and stakeholders.
During the breakout group sessions, participants noted that there is a strong stakeholder need for both seasonal predictions (used in planning for fishing, research cruises, industry activities, etc.) and decadal predictions (used in infrastructure planning, national security planning, environmental assessments, endangered species status, etc.). The groups indicated that making predictions on the interannual time frame is particularly difficult. Suggested next steps include work on the question of atmospheric forcing (this can help bridge the gap between the seasonal and decadal timescales), and on the treatment of the ocean in models (models cannot currently resolve vertical stratification and heat fluxes). Other topics that the groups discussed include the transition from first-year ice to multiyear ice, the type of model (statistical, physical) and initializations that
should be used for seasonal predictions, coordination opportunities with stakeholders and observationalists, and sensitivity and process studies (including oceanic and atmospheric components) that will improve particular types of forecasts.
CHALLENGES AND OPPORTUNITIES
The workshop concluded with a discussion on the challenges and opportunities in sea ice prediction in the coming decades. Cross-cutting issues and coordination opportunities were discussed by the panelists and participants. Jim Overland from NOAA/ Pacific Marine Environmental Laboratory suggested that researchers should focus on the specific science question of why the ice extent is so low (related to the existence of thin, mobile sea ice). He also noted that models have improved in the past five years in certain aspects, but that significant work remains, particularly in reducing the range of model projections. He points out that, in the “real world” Arctic region, there are important dynamic changes occurring on scales that we cannot yet measure (e.g., large temperature anomalies across small areas). Brendan Kelly of Interagency Arctic Research Policy Committee brought the discussion back to the importance of sustained dialog and in-depth conversations with stakeholders. He noted the significance of making sure that we are asking the right questions and that we are defining the problem appropriately to address stakeholder needs. He challenged the participants to act as ambassadors to their communities in an effort to help others understand the depth and scope of stakeholder needs related to sea ice prediction.
Pablo Clemente-Colón of the National Ice Center commented on the rapidly changing seasonality of Arctic sea ice conditions and the impact that it will have on the type and frequency of measurements being taken. He noted that changes in the amount and location of multiyear ice will directly affect the placement of buoys, for example. To help solve this problem, he suggested that new strategies for in situ observing capabilities will need to be developed, in addition to improvements of currently existing observing systems that could include the integration of new unmanned airborne system and autonomous underwater vehicle technologies. Jean-Claude Gascard of the Universite Pierre et Marie Curie agreed that the main parameters characterizing Arctic sea ice have changed drastically during the past 30 years, and that powerful feedback mechanisms link sea ice with the atmosphere and ocean. He reiterated the significance of the reduction of multiyear ice and noted that a thinner sea ice regime can exhibit less predictability than a thicker regime. He also pointed out the need for process-oriented studies in the atmospheric, sea ice, and oceanic domains, but acknowledged that there are still questions related to what we can predict and how well it can be done. Opportunities for collaboration between observationalists and modelers exist in addressing the issue of trends in variability, with specificity by region. He noted that the data collected over the past 30 years provides unique
opportunities for synergies between the observational community and modelers (reanalysis of the past 30 years is important to improve model prediction in the future).
During the final breakout group discussion session, participants noted the need for an ongoing and sustained conversation with stakeholders on what data they want, what they need, and what they can use coupled with a conversation of what forecasters might currently provide, what they might provide soon, and the associated challenges. The groups also noted the importance of changing ice conditions in the Arctic (e.g., the transition from multiyear ice to first-year ice), the need to improve observational capabilities to meet modeling needs, the issue of data continuity, and the opportunity to take advantage of new technologies and collaborations to increase our current understanding. Participants acknowledged that the Arctic is a complex, integrated system including ocean, ice, and atmospheric components and should be treated as an integrated whole.
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