Enhance understanding and improve predictions of the changing sea ice cover
Arctic sea ice is a geophysical phenomenon within a socio-ecological system, and as such it provides a variety of services (Eicken et al. 2009). They are: regulating services, e.g., the impact of sea ice on the surface energy budget plays a vital role in regulating the global climate; provisioning services, e.g., sea ice yields food for communities that harvest marine mammals for which the ice is a habitat; cultural services, i.e., non-material benefits of a cultural, spiritual, and educational nature contributing to the dailylife of communities; and supporting services, e.g., micro-organisms, although not harvested directly, are an important component of a food web that sustains marine mammals and fish. Viewed from this geophysical/socio-ecological perspective, enhancing understanding and improving predictions of the changing sea ice cover will benefit from cooperation between sea ice researchers and numerous potential collaborators, including northern residents, who have particular Local and Indigenous Knowledge of the ice.
The Arctic sea ice cover is changing dramatically. The end-of-summer minimum sea ice extent (areal coverage) and the end-of-winter maximum sea ice extent have decreased by 40 percent and 9 percent, respectively, over the course of the satellite passive microwave observation period 1979-2015 (Fetterer et al. 2002, updated daily).The age and thickness distributions of the ice cover are also decreasing as the area of seasonal ice increases at the expense of the older, thicker perennial ice (Kwok and Rothrock 2009; Perovich et al. 2015). The resultant decrease in sea ice volume contributes to an increase in observed ice drift speeds (Kwok et al. 2013), and is likely responsible for higher deformation and ridging rates (Zhang et al. 2012). Pressure ridges are the thickest sea ice features and result from collisions between moving icefloes.
As the sea ice changes, there are many environmental and socio-ecological consequences. They include: direct effects on marine ecosystems and northern communities (Harwood et al. 2015; Kedra et al. 2015; Pearce et al. 2015; Ray et al. 2016; Tremblay et al. 2015), and indirect effects on terrestrial ecosystems (Bhatt et al. 2013); increasing ocean surface wave height, storm surge intensity, and coastal erosion and inundation (Overeem et al. 2015; Vermaire et al. 2014; Thomson and Rogers 2014) that threaten habitats, northern communities, and civil and defense infrastructure (Gibbs and Richmond 2015); rising sea surface temperatures (Timmermans and Proshutinsky 2015) and ocean primary production (Frey et al. 2015); a reduction in the earth's reflectivity, accounting for about 25 percent of the warming due to increasing atmospheric CO2 (Pistone et al., 2014); and tropospheric warming, which is amplifying global warming in the Arctic (Serreze and Barry 2011), and might be weakening the jet stream and contributing to more extreme weather in mid-latitude regions (e.g., Francis et al. 2014).
The changing sea ice cover, particularly the decreasing minimum extent and associated increase in the area of summer open water, is opening the region to increased ship traffic for cargo and tourism (e.g., Stephenson and Smith, 2015) and extraction of natural resources such as oil and gas, minerals, and fish (e.g., National Petroleum Council, 2015). In turn, growth in such activities has implications for homeland and national security such as search and rescue policy, oil spill preparedness and response, and domain awareness. Current model projections of sea ice extent show that a nearly ice-free Arctic Ocean at the end of summer is a distinct possibility later this century, although there remains considerable uncertainty as to when that will happen (e.g., Stroeve et al. 2012). Agencies responsible for emergency response and security have documented the need for capabilities that are informed by science ( 2013; 2013; U.S. Navy 2014).
During the period of consistent satellite passive microwave observations (1979-present), most numerical models have projected a slower rate of ice loss than the observed rate, with the best-performing models typically including more sophisticated ice processes (e.g., Stroeve et al. 2012). Enhancing understanding and improving predictions of the changing sea ice cover over a range of spatial and temporal scales (hourly, daily, weekly, seasonal, annual, decadal) requires research that addresses the physicalproperties and processes of the ice itself (e.g., ice thickness, topography, and strength; ice motion and deformation; distribution and properties of snow on ice; and melt pond characteristics). These sea ice characteristics, in turn, are strongly influenced by the atmosphere above and the ocean below the ice. Consequently, it is necessary to take a systems approach that accounts for atmospheric and oceanographic conditions and processes and examines the interactions and feedbacks among the sea ice, atmosphere, and ocean.
The Sea Ice Goal focuses on ice and ocean conditions and processes. Progress in the implementation of the Sea Ice Goal will also contribute to and benefit from research undertaken under the Atmosphere, Marine Ecosystems, Coastal, and Environmental Intelligence Goals. The Sea Ice Goal, and its broader connections to these other components of the Arctic environmental system, 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 sea ice cover affect the well-being of Arctic residents (Well-being), the functioning of the marine environment (Stewardship), regional and national security (Security), and potentially regions far beyond the Arctic (Arctic-Global System).
The work focuses on the following objectives