Researchers:Vladimir Alexeev and Jessica Cherry
Funding Source: NSF CA
Collaborators: Maria Tsukernik (NCAR), O. Byrkjedal, Wind Teknikk (Oslo, Norway, formerly at Bergen University)
Researchers: William Hibler, and Jennifer Hutchings, David Atkinson, Andrew Roberts, IARC, UAF
Funding source: NSF, Jamstec
Collaborators:
Jet Propulsion Laboratory, USA
National Center for Atmospheric Research, USA
Wood Hole Oceanographic Institution, USA
University of Tasmania, Australia
University of Wisconsin, USA
The ice-ocean-atmosphere project is an initiative to improve our understanding of the role of sea ice in the arctic climate system. Sea ice interacts with the ocean and atmosphere by acting as the interface for ocean-atmosphere heat and moisture fluxes, rejecting brine that influences mixing in the ocean, and by transporting freshwater. Freshwater transport into the Greenland Sea and down the Labrador Sea may have profound effects on oceanic overturning in the North Atlantic. Atmospheric circulation and global heat budget may be sensitive to changes in the sea-ice pack. The sea-ice mass balance (thickness distribution) and transport regulates all of these processes. Dynamical processes involving the deformation of ice, such as ridging and lead opening, are an important component of the evolution of the sea ice thickness distribution. Sea ice responds in a highly non-linear way to perturbations in atmospheric and oceanic forcing, due to the pack ice material properties and plastic deformation. Researchers are working towards an improved understanding of dynamic sea ice processes, and their influence on the Arctic climate.
Sea-ice deformation oscillates within a 12 hour time period at all times of years, and this oscillation has been observed throughout the arctic and Weddell Sea. Researchers are developing coupled ice-ocean tidal-inertial models to simulate this phenomena. There is a considerable field work and remote sensing element in this project, as we draw upon in-situ measurements and SAR data in process studies focused on understanding the nature of high frequency sea ice deformation.
Researchers are also interested in the long timescale (interannual and multi-decadal) variability of sea ice. In particular, the highly non-linear nature of the viscous-plastic sea ice model allows for multiple equilibrium states that suggests sea ice could flip between thick and thin aarctic sea-ice states through small perturbations to the atmospheric forcing. Modeling studies are being conducted to better understand this phenomena in the context of past arctic climate changes.
Correct representation of dynamic processes in sea ice models requires the constitutive relation for sea ice to be well known, so that the stress and strain state of the ice pack is correctly resolved. Researchers are working on the development of rheological models of sea ice that reproduce observed orientations of failure zones in the Arctic ice pack. This work takes a joint modeling, laboratory strain testing and in-situ observation approach and is in collaboration with Erland Schulson at Dartmouth College.