OPP-PRF: The Marginal Ocean Zone: Definition, Dynamics, and Implications for a Changing Arctic Ocean through Model-Observation Synthesis

University Of Washington, Seattle WA

Investigators

Abstract

The Arctic Ocean is one of the most rapidly changing regions of the World Ocean. Specifically, the Seasonal Ice Zone, which is the area covered by sea ice in winter but not in summer, is growing. As this area grows, the physical processes that influence ocean motion and ocean properties like temperature, salinity, and stratification are changing. These changing physics influence net primary productivity, air-sea gas exchange, as well as processes up the trophic levels, including impacting native communities, local fisheries, and global shipping patterns. However, it is challenging to take measurements of the ocean in this region. This research will combine all available data to determine the important physical processes responsible for ocean motion and properties in the Seasonal Ice Zone. This will advance current understanding of ocean-dynamics in the vicinity of the ice edge, and thus will influence current understanding on a host of interdisciplinary topics related to Arctic Ocean and sea ice change. Significant work has been done to characterize a sub-region of the Seasonal Ice Zone known as the Marginal Ice Zone, which represents the region within the 15% ice concentration contour. This definition, however, is ice-centric. This project will approach the question from an ocean perspective. The researchers hypothesize the existence of the Marginal Ocean Zone, a region of the ocean which exhibits distinct dynamics from both the Marginal Ice Zone and the open ocean. This research will characterize the hydrographic conditions across spatio-temporal scales in this region of the Arctic Ocean. Specifically, the project will synthesize all available data to derive a universal definition for the Marginal Ocean Zone based on ocean properties like temperature, salinity, and stratification. This project will then quantify the seasonal evolution of properties within the Marginal Ocean Zone as well as the regional differences in these dynamics. Subsequently, the project will quantify the importance of synoptic scale processes and atmospheric forcing on the mixed layer dynamics, as well as on the heat and freshwater content of the Marginal Ocean Zone. Long-term changes within the Arctic Ocean are influencing circulation patterns, dynamics, and climatic-scale feedbacks. This work will diagnose, quantify, and explain long-term changes within the Marginal Ocean Zone. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.