Sensitivity of Arctic Ocean Change to Background Mixing

University Of Washington, Seattle WA

Investigators

Abstract

Morison 0909408 University of Washington Direct measurements of oceanic mixing are difficult, but decades of research suggest that deep background mixing is a consequence of dissipation of internal wave energy. The exact nature of this relationship is an open question, but it makes it possible to infer mixing from relatively simple observations of internal wave energy. The anticipated increase of summer ice-free waters in the Arctic should result in an increase in internal wave energy in the ocean and potentially unanticipated consequences for ocean processes and climate. The PI will analyze existing ocean data for internal waves and mixing using new methods, which in many cases have not been applied to the Arctic environment. The techniques will be tested against direct measurements of mixing done in an experiment by a collaborating Norwegian scientist. He will use existing data to examine the relation of mixing and internal waves and the relation of internal wave energy to the ice cover. He will also perform a simple study of the energetics of internal waves that combines existing ideas about the forcing of internal waves with new ice model results. Sensitivity studies with a large-scale ice ocean model will explore the Arctic Ocean model behavior under specified temporally and spatially varying background mixing and the potential for a positive ice-mixing feedback on climate.