Journal
JOURNAL OF PHYSICAL OCEANOGRAPHY
Volume 35, Issue 9, Pages 1689-1711Publisher
AMER METEOROLOGICAL SOC
DOI: 10.1175/JPO2780.1
Keywords
-
Categories
Ask authors/readers for more resources
Observations of the three-dimensional structure and evolution of a thermohaline intrusion in a wide, deep fjord are presented. In an intensive two-ship study centered on an acoustically tracked neutrally buoyant float, a cold, fresh, low-oxygen tongue of water moving southward at about 0.03 in s(-1) out of Possession Sound, Washington, was observed. The feature lay across isopycrial surfaces in a 50-80-m depth range. The large-scale structures of temperature, salinity, velocity, dissolved oxygen, and chlorophyll were mapped with a towed, depth-cycling instrument from one ship while the other ship measured turbulence close to the float with loosely tethered microstructure profilers. Observations from both ships were expressed in a float-relative (Lagrangian) reference frame, minimizing advection effects. A float deployed at the tongue's leading edge warmed 0.2 degrees C in 24 h, which the authors argue resulted from mixing. Diapycnal heat fluxes inferred from microstructure were 1-2 orders of magnitude too small to account for the observed warming. Instead, lateral stirring along isopycnals appears responsible, implying isopycnal diffusivities O(1 m(2) s(-1)). These are consistent with estimates, using measured temperature microstructure, from an extension of the Osborn-Cox model that allows for lateral gradients. Horizontal structures with scales 0(100 in) are seen in time series and spatial maps, supporting this interpretation.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available