Emerging Issue Summary
CHANGING SEA ICE/OCEAN CONDITIONS

Highlights:
  • Sea ice extent, type, and concentration information is available daily from the National Ice Center (NIC) for the North Slope adjacent ocean areas. These observations are derived from a suite of satellite data that, depending on cloud cover, varies from 200 m to 25 km in spatial resolution. Improved resolution is desirable.
  • Historical ice data derived from satellites for the North Slope go back to 1979 and are available through the National Snow and Ice Data Center (NSIDC), National Oceanographic Data Center (NODC), and the Canadian Ice Service (CIS).
  • Wind, wave, and ice observations for the open ocean are provided daily during the open water season from a combination of satellite observations and National Oceanic and Atmospheric Administration (NOAA) buoys; however, there is not the long historical record of these observations as in the case of sea ice.
  • There is an overarching need for high quality, user-friendly access to data and model projections for sea ice and ocean changes that are specific to local conditions.
  • Historic information (both remotely sensed and local traditional ecological knowledge) can be useful in assessing ice conditions.
  • More research is needed to understand fate and effects of oil spills in sea ice during freeze-up and spring melts.
  • A series of actions, beginning with a synthesis workshop, is recommended.
Ice
Chukchi Sea ice buckling under changing sea conditions. (Ben and Deb Greene, NSB)


Overview and Management Relevance:

Changing sea ice and ocean conditions will affect marine ecosystems and resource access, development and management. Each potential impact presents its own unique set of questions and need for data acquisition and model development. For instance, oil spill response requires evaluation of existing technologies as well as scenario modeling and risk assessment in the context of potential ice conditions. Alaska Clean Seas (ACS) presently has a contingency planning process for oil spills in ice-covered waters, but these plans do not account for the rapidly changing ice conditions projected over the next decade. In the case of sea ice as a platform for subsistence hunting, data must be collected in the form of traditional local knowledge as well as correlation of changing ice conditions with records of changing harvest locations and success. Effects of wave regime on erosion patterns will depend on detailed local bathymetry. Understanding the potential effects of ice melt on contaminant load requires models of ice changes and atmospheric models of airborne contaminants and deposition on snow and ice. All of these issues share an overarching need for high quality, user-friendly access to present and historical data and model projections for sea ice and ocean changes specific to local conditions. The website for the “Sea Ice Outlook” (http://www.arcus.org/search/seaiceoutlook) is a step in the right direction. We understand the Alaska Ocean Observing System (AOOS) is also addressing this problem; NSSI-GINA personnel should coordinate their efforts with AOOS to avoid duplication.

In the Arctic, much of the focus to date has been on changes in sea ice, water temperatures, and related water movements (currents). However, ocean acidification may become increasingly important or even as important as changes in sea ice, water temperatures, and related water movements in the coming decades. The importance of ocean acidification in the Arctic and the need for monitoring or research needs to be assessed.

Aside from the issue of ocean acidification, the emerging issues related to sea ice and ocean condition all require that historic ice records be extracted and compiled in a user-friendly form to be made available across agencies, recognizing the important distinctions between shore-fast and pack ice. Some recent ice extent mapping projects have recognized the distinction between shore-fast and pack ice; however, the historical data sets typically do not make this important distinction. Reliable satellite data exist since 1979. There are also other less quantitative data sources that provide some information into the 1800s, including traditional and local knowledge, whaling records, and submarine observations. For instance, see the work of Shapiro and Metzner (1979) on this topic.1

The National Ice Center (NIC) provides daily estimates of sea ice cover. According to the NIC, “The resolution of the initial product is 25 km. However, this resolution is relative due to the nature of the shape file in GIS software. Further, inputs to the data can range in resolution from 200 m to 25 km. These inputs include RADARSAT, DMSP OLS, AVHRR, and QUIKSCAT. The SSM/I contour uses the NASA Team 2 algorithm and is contoured using the 10.1 percent value. In the Lowgrain Ice Edge, the information is removed at a 2,000 meter interval to provide a smaller, more portable product.” The NIC has acquired data back to 2004. Weekly ice charts similar to these dating back to the 1970s can be obtained from the Canadian Ice Service. The National Snow and Ice Data Center, located at the University of Colorado, maintains the passive microwave data of ice extent dating back to 1979.

Identification, evaluation, and recommendation of applicable models and nested models are needed for regions of interest. Where necessary, these models will have to be downscaled to address specific issues and local conditions (e.g., Beaufort and Chukchi Seas), and produce user-friendly projections (e.g., 2, 5, 10, 20 years) that can be used across agencies. There are many models available – the task would be to identify which models can be downscaled to regional and local resolution and to determine how reliable they are when applied on a local level. Where reliable models do not exist, historical, hind-cast, and re-analysis of data can be used to project future trends.

From these models and trend analyses, we foresee an increased ability to proceed to impact modeling, allowing improved predictions for things like erosion, species distribution, oil spill response, infrastructure needs, subsistence impacts, etc., by incorporating the unique variables and approaches necessary to address individual issues. The models need to provide an estimate of the range of conditions of changing sea ice, wave regime, and open water extent to support engineering design of offshore and coastal land structures.

Recent reconstruction of sea ice historical extent reveals that recent conditions represent the lowest ice extent in 800 years (Journal of Climate Dynamics). If recent changes in sea ice cover and increasing temperatures in the Bering Sea persist, they will have profound effects on marine communities. Development and maintenance of a database of the spatial extent and characteristics of sea ice as well as indices of timing and extent of the spring bloom is a high priority.

Many of the emerging issues are interrelated. To foster a system science approach that would provide information needed for design and management to support NSSI stakeholders, a series of Synthesis/System workshops is needed to bring together scientists and agencies across disciplines under the umbrella of NSSI, allowing consideration of whole systems as they relate to sea ice.

The success of these endeavors will depend on a strong commitment to sustainable long-term monitoring.

Recommendations:

  1. Assess the importance of ocean acidification in the Arctic and the need for monitoring and related research.
  2. Conduct under NSSI sponsorship a series of interdisciplinary synthesis/system workshops to discuss specific emerging issues and their relationship to sea ice.
  3. Continue the research needed to better understand ice fate and effects of oil spills in sea ice during fall freeze up and spring melt.
  4. Task NSSI-GINA to compile North Slope relevant data from NIC, NSIDC, NODC, and MMS information on sea ice and open ocean conditions. Put these data in a format that is user-friendly, accessible, and can be easily visualized.
  5. Based on synthesis meetings, identify additional model needs and output locations, time scale, and spatial resolution of relevance to North Slope users. Candidate models then need to be evaluated and an appropriate model(s) recommended.
  6. Use the selected models to make 2-, 5-, 10-, and 20-year projections of changes in sea ice and, to the extent that it is possible, biological communities.
  7. In the absence of appropriate models, use historical data and other means to create retrospective hind casting relevant to North Slope users. This should be done in parallel to the modeling effort.
  8. The sea ice and wave climate predictions resulting from the modeling effort should then be coupled with specific impact models such as ocean circulation, changing food web, contaminant transport, shore erosion, anthropogenic near-shore operations, habitats, oil spill response, and subsistence hunting.

 

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1 Shapiro, L.H. and R. C. Metzner. 1979. Historical references to ice conditions along the Beaufort Sea Coast of Alaska. Environmental Assessment of the Alaskan Continental Shelf (OCSEAP) Annual Reports, 1979, Volume 9 (Hazards), pp. 632-682.