HR: 16:00h
AN: OS12C-01 INVITED     [PDF]
TI: Observing and Modeling the Arctic-Atlantic Climate Connection
AU: * Rhines, P
EM: rhines@ocean.washington.edu
AF: University of Washington, Box 357940, Seattle, WA 98195 United States
AB: Communication of fresh water, heat, volume and tracers between Arctic and subpolar oceans bears on the meridonal overturning circulation and climate. The spectrum of fresh water transport will be discussed, and illustrated using observations from Davis Strait and several numerical circulation models. Glaring sensitivity in both models and observations is seen on shallow continental shelves and in neighboring boundary currents. The steric height contributed by low-salinity surface waters provides a dominant resistance to deep convection, and its geography is particularly rich and difficult to resolve. As a result, our image of the balance between Labrador Sea Water and deeper overflow waters in the construction of North Atlantic Deep Water is model-dependent and observational-array dependent. It follows that the intensity and focus of decadal variability of models also depends on this balance. A somewhat analogous problem exists in the atmospheric storm track overhead, whose location and intensity bears heavily on these oceanic fluxes. The Atlantic storm track involves continous propagation of cyclonic systems from mid-latitudes to high in the Arctic. These storms are embedded in the larger cyclonic backgroung low which invades the Arctic in years of high NAO index. Wind ducts exist in the complex, strong topographies of the Canadian Arctic Archipelago and the Greenland ice cap, and the slipperiness of upper-ocean low-salinity water (owing to its buoyant inhibition of mixing) makes it susceptible to this stress. Strategy for long-term observations of ocean circulations and atmospheric forcing critcial to decadal climate variability in the Arctic/SubArctic system will be discussed.
UR: http://www.ocean.washington.edu/research/gfd/gfd.html
DE: 1620 Climate dynamics (3309)
DE: 4207 Arctic and Antarctic oceanography
DE: 4215 Climate and interannual variability (3309)
DE: 4255 Numerical modeling
DE: 4532 General circulation
SC: Ocean Sciences [OS]
MN: 2003 Fall Meeting