Shearmeter Floats in the Area of the WHOI Brazil Basin Tracer Release Experiment: Technical and Oceanographic Data

• Main Authors: Duda, Timothy F., Guest, Brian J., Wooding, Christine M., Jones, Clayton M., Lelievre, Scott
• Other Authors: WOODS HOLE OCEANOGRAPHIC INSTITUTION MA
• Format: Text
• Language: English
• Published: 2002
• Subjects: Physical and Dynamic Oceanography; *OCEANOGRAPHIC DATA; *OCEAN BASINS; MATHEMATICAL MODELS; TIME SERIES ANALYSIS; FLOATS; ABYSSAL ZONES; OCEAN BOTTOM; TIDES; BOTTOM WATERS; BRAZIL BASI; GARRETT MUNK MODEL; BBTRE(BRAZIL BASIN TRACER RELEASE EXPERIMENT); Antarctic; Munk; Antarc*
• Online Access: http://www.dtic.mil/docs/citations/ADA400088; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA400088

Six drifting floats designed to measure shear were deployed in the vicinity of the Brazil Basin Tracer Release Experiment. The one-year long time series of oceanographic conditions obtained by the floats are for direct comparison with long-term tracer dispersion. The purpose of the tracer dispersion experiment was to study mixing of Antarctic Bottom Water at approximately 4000 m depth with less dense water above. Two of the floats returned shear records, one from about 1660 m depth and one from about 2800 m depth. Mean shear at 1660 m was 2.2 x 10(exp -3)/s with N = 1.1. cph, about 1.9 times the Garrett-Munk model amount. Mean shear at 2800 m was 1.1 x 10(exp -3) with N = 0.5 cph, about 2.2 times Garrett-Munk. There was no apparent depth structure to the shear recorded by the near-bottom float moving over the mountainous seafloor. The two shear time series and the local tidal velocities were not strongly correlated, but the tide and shear series did have some similarities. Some variability in the 1660-m shear may be due to atmospheric forcing. Three floats deeper than 2800 m returned one-year long trajectories. Two trajectories were persistently eastward. --Original contains color plates: All DTIC reproductions will be in black and white.