A Modular Approach to Building an Arctic Observing System for the IPY and Beyond in the Switchyard Region of the Arctic Ocean

This collaboration consists of 0633878 (Schlosser, Columbia University, LEAD), 0633885 (Steele, University of Washington) and 0633343 (Kwok, NASA). In this continuation of the Switchyard project (Steele/Schlosser/Kwok, 0230427), researchers will establish a long-term Arctic Ocean observing system component in the switchyard region of the Arctic Ocean north of Greenland and Ellesmere Island, Canada. The project will continue and expand two aircraft-based hydrographic surveys between Alert and the North Pole for long-term observation. The Columbia University team will use a Twin Otter aircraft to measure hydrographic properties and a set of tracers aimed at resolving relative age structure (CFC s, tritium/3He) and freshwater components (18O and Ba) in the upper water column utilizing the Arctic CTD/rosette system on a section between Ellesmere Island and the North Pole. This modular system is deployed through a 12 hole drilled through the sea ice and traces T, S, and DO, while at the same time allowing the collection of up to 12 water samples. The University of Washington team led by M. Steele will measure hydrographic properties in the Lincoln Sea, up to 500 km away from shore, using helicopters and Twin Otter aircraft to capture the structure and transport of the water masses coming around the Canadian Basin on their way to Nares and Fram straits. To complete the quantitative assessment of the transport of the water masses from the Canadian Basin towards Nares Strait and Fram Strait, a University of Washington team led by C. Lee will deploy lightweight moorings across the shelf just west of Nares Strait to separate the individual transports through these straits. In situ observations will be augmented by R. Kwok from the Jet Propulsion Laboratory (JPL), who will examine satellite-derived observations of the sea ice motion and mass budget.