Warming of Greenland Sea deep water induced by abyssal mixing

• Other Authors: Walter, Maren
• Language: English
• Published: Staats- und Universitätsbibliothek [Host] 2004
• Subjects: Greenland; Greenland Sea
• Online Access: http://nbn-resolving.de/urn:nbn:de:gbv:46-diss000008518; http://webdoc.sub.gwdg.de/ebook/diss/Bremen/2004/E-Diss851_mwalter_thesis.pdf

Greenland Sea, Deep Water, Mixing, Turbulence, ADCP, LADCP, Warming, Finescale, Shear, Strain, Density, Overturns, Ventilation. - In the absence of deep convection, the Greenland Sea Deep Water has experienced a slow but significant warming during the 1980s and 9́0s. Enhanced vertical mixing can explain the observed trends of several propertiesincluding anthropogenic tracers, but the necessary mixing ratesare at the higher end of those observed elsewhere in the ocean.In this work, the mixing is studied by means of the spatial distribution and strength of eddy diffusivities. These are calculated from energy dissipationrates, which in turn are estimated with two complementary methods.Thorpe scales provide a direct estimate of the dissipation from densityoverturns. The second method uses a spectral estimate of the finescale variances of velocity shear density strain as proxies for the energy content of the internal wave field, and the equlibrium energy dissipation rate. Both methods are applied on a data set obtained duringsummer 1998, comprising loweredADCP measurements of the velocity field in the central Greenland Sea and near the surrounding ridge systems, as well . @Bremen, Univ., Diss., 2004