Collaborative Research: Understanding Arctic System Change Through Synthesis of Hydrographic and Sea Ice Observations from the early 21st Century

Observations made since the turn of this century indicate that the Arctic physical environment and associated ecosystems are undergoing remarkable changes and to predict future changes we need to be able to quantify how much of Arctic climate variability and change is linked to the ocean circulation, how the distribution of sea ice responds to the amplified Arctic warming predicted by climate models, and how primary productivity, species distributions and associated ecosystem structures will change with the evolving Arctic state. Our understanding of the driving mechanisms for these processes depends on our knowledge of the Arctic system and our ability to simulate its time-evolving state in a way that is consistent with observations. This project will employ an advanced approach for synthesizing oceanographic observations to develop a tool that establishes a baseline understanding of the Arctic system. Outcomes of this research will include better quantification of the Arctic system's changes since the turn of the century, and improved understanding of the dynamical causes for these changes. It is likely that the resulting analyzed fields of ocean and sea ice properties will be widely utilized by the community in future research. This project will bring together hydrographic observations obtained from ship, aircraft and autonomous instruments, sea ice data from in situ buoys, satellites and manned vessels, and boundary-layer meteorology within a state estimation infrastructure to develop a physical and dynamical description of the evolving Arctic Ocean during roughly the first decade of the 21st century. Taking advantage of a growing observational database, the project's two main objectives are: the creation of a dynamically-consistent and comprehensive synthesis of all available Arctic hydrographic and sea ice observations using the adjoint-based Arctic Sub-polar gyre sTate Estimate for the period 2002-present; and scientific investigations, using the synthesis products, of physical mechanisms driving the evolving Arctic system. The team will quantify four key science issues: the time-average, seasonal cycle, and interannual variability of the upper-ocean hydrography and circulation; the interannual changes in Arctic Ocean heat and freshwater (FW) content; changes in the sea ice state and air-sea fluxes; and connections between the Arctic and the Sub-polar gyre, focusing on heat and FW exchanges and feedback. Products generated will be the time-mean, mean seasonal cycle, and time-varying quantities in the Arctic Ocean, its neighboring seas and sub-polar North Atlantic of the full set of variables characterizing the coupled physical ocean-sea ice state, heat, FW, momentum and vorticity budgets, and inferred air-sea fluxes and time-mean oceanic turbulent mixing. These products will be made available to researchers and students, policy makers, industry, and the general public. A substantial outreach activity will be undertaken, in collaboration the MIT Museum, to assemble diverse multimedia projects that use scientific results, including those from this project, to visualize changes due to ongoing major shifts in the Arctic Ocean. The goal is to engage the general audience interested in the multimedia projects with actual scientific datasets to establish tangible links between the two perspectives. Exhibitions and accompanying events are planned with a goal of creating material that may be readily used for broader dissemination. The project will support two female early career scientists.