Lagrangian Study of the Iceland-Faroe Front. Part II: Analysis and Synthesis

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ABSTRACTOCE-0623210Intellectual Merit: A Lagrangian study of the inflow of shallow and warm North Atlantic water across the Iceland-Faroe Ridge, along the Iceland-Faroe Front (IFF), and into the Norwegian Sea has previously been funded as a cooperative effort between the University of Rhode Island (URI) and the Institute of Marine Research (IMR) in Bergen, Norway. A major objective of that study was to understand the basic features of the IFF: its mean and time varying structure, from which side of the Iceland Basin its waters come, and where and how they continue downstream. Sixty floats from URI were deployed at 200 dbar to the south of the Iceland-Faroe Ridge to examine the shallow pathways of warm North Atlantic waters across the Ridge and beyond into the Norwegian Sea, and 30 floats from IMR were deployed at 800 dbar just north of the Ridge to focus on the flow of Arctic intermediate waters. These floats will have completed their mission and surfaced by the spring of 2006, and preliminary processing is expected to be complete by the end of that summer. The primary purpose of this analysis and synthesis project is to continue the original scientific objectives of the field program, but also extend those ideas to incorporate new ideas and collaborations. The RAFOS float data will be used to map the pathways, develop quantitative estimates of the transport across the Iceland-Faroes Ridge, the eddy variability in the IFF, and the exchanges and mixing with the Norwegian Sea Water to its north, and a description of the bifurcation of the IFF into the northern and southern Faroe Current. As is well-known, floats can be very effective at identifying pathways of transport and mixing, while the corresponding velocities and their variability in and along the front give information on the front's structure and downstream evolution. Broader Impacts: The analysis of these observations will enhance our understanding of the penultimate link in the northward transport of warm water in the thermohaline circulation (the final step being deep convection in the Nordic Seas). The dynamics of the ocean that controls the pathways and the transport of warm water over the Iceland- Faroes Ridge also serve to control the climate over northern Europe. The results of the RAFOS float analysis will be shared closely with collaborators, both observationalists and numerical modelers, in Norway and Sweden so that a coherent and comprehensive picture of the both the shallow and intermediate circulation can be made. All the data and results from this project will be made available to the community through submissions to data centers, presentations at national and international meetings, and publication of technical reports and scientific papers.