The Eastern Eurasian Basin: Rerouting fresh water between the Eastern and Western Arctic in response to atmospheric and oceanic forcings

University Of Alaska Fairbanks Campus, Fairbanks AK

Investigators

Abstract

Large amounts of freshwater from rivers enter the Arctic Ocean through the eastern Eurasian Basin (EEB) during the spring, summer, and fall. The EEB acts like a railroad switch, controlling where that freshwater moves within the Arctic Ocean and sub-polar seas. The freshwater input from rivers is increasing as the Arctic warms. This makes understanding processes in the Eastern Eurasian Basin especially important. This study aims to understand how the EEB redistributes ice and fresh water between the eastern and western Arctic in response to changes in the atmosphere. Three biennial cruises, planned for August-September, will take measurements between Franz Josef Land and the central East Siberian Sea, following a path that moves from shallow water to the deep sea. The sampling program connects observations using moorings, ship sampling, and drifters. These efforts will inform the scientific community and the broader public about major changes in the EEB that could impact the state of Arctic ice cover, marine ecosystems, and areas further south. The proposed observations are also important for developing estimates for future summer sea-ice conditions, which are valuable information for national security, the transportation industry, and weather forecasting. A graduate student and a K-12 teacher will join the cruises to engage in research. Together with a researcher, they will share and reach out to classrooms and the general public. The project will support one graduate student. The eastern Eurasian Basin (EEB), including its shelves distributes ice and Arctic riverine water between the Eastern and Western Arctic. This provides the shortest pathway for Arctic freshwater to the sub-polar seas where weak stratification leads to deep convection, a key mechanisms of global thermohaline circulation. Recent observations have captured unprecedented changes in the EEB, likely representing a fundamental shift to a new, less stable, more dynamic mode. The goal of our study is to develop a comprehensive and quantitative understanding of how the EEB functions, accumulating and releasing major Arctic riverine transports and redistributing ice and fresh water between the Eastern and Western Arctic in response to atmospheric and oceanic forcings. Quantifying EEB freshwater inventories and transports, following alternating atmospheric regimes, will be critical to future understanding of the Arctic Ocean's oceanography. This program will provide sustained measurements in critical areas; data and products, critically-needed benchmarks for Arctic satellite sea-ice and altimeter measurements, will be publicly available. 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.