Sound Velocity Structure of the Labrador Sea, Irminger Sea, and Baffin Bay during the NORLANT-72 Exercise

• Main Authors: Fenner, Don F., Bucca, Paul J.
• Other Authors: NAVAL OCEANOGRAPHIC OFFICE NSTL STATION MS
• Format: Text
• Language: English
• Published: 1974
• Subjects: Physical and Dynamic Oceanography; Acoustic Detection and Detectors; Acoustics; *ACOUSTIC VELOCITY; *NORTH ATLANTIC OCEAN; *UNDERWATER SOUND; POLAR REGIONS; SPATIAL DISTRIBUTION; TEMPERATURE; OCEAN CURRENTS; BATHYTHERMOGRAPH DATA; OCEAN RIDGES; SUMMER; DEEP WATER; ACOUSTIC DATA; SEA WATER; CONVERGENCE; MIXING; SALINITY; *LABRADOR SEA; *BAFFIN BAY; *IRMINGER SEA; NORLANT 72 PROGRAM; DENMARK STRAIT; LRAPP(LONG RANGE ACOUSTIC PROPAGATION PROJECT); LONG RANGE ACOUSTIC PROPAGATION PROJECT; DAVIS STRAIT; DEEP SOUND CHANNEL; OCEAN CURRENT MEANDERS; NORTH ATLANTIC CURRENT; LABRADOR CURRENT; WEST GREELAND CURRENT; SUBARCTIC CONVERGENCE; BAFFINLAND CURRENT; Baffin Bay; Irminger Sea; Reykjanes; Baffin; Davis Strait; Denmark Strait; Labrador Sea; north atlantic current; North Atlantic; Subarctic
• Online Access: http://www.dtic.mil/docs/citations/ADC000461; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADC000461

During July-September 1972, 439 oceanographic observations were taken as part of the NORLANT-72 Exercise. One-third of these observations, mostly expendable bathythermographs, were converted into sound velocity profiles using Wilson's equation and historical salinities. These data were adequate for temporal and spatial analysis in the central Labrador Sea and along tracks between this region and the Denmark Strait, Reykjanes Ridge, and the Carey Islands in northern Baffin Bay. Oceanographic data also were adequate to define meandering of the Subarctic Convergence in the central Labrador Sea throughout the three exercise phases. Sound velocity profiles throughout the exercise area were extremely complex and variable, particularly in the central Labrador Sea and just south of Davis Strait. At one station astride the Subarctic Convergence, the sound velocity at the deep sound channel (DSC) axis varied by 9.5 m/sec over less than 48 hours. In the intense transition zone south of Davis Strait, this parameter varied by 20.9 m/sec over a distance of 155 nm. The depth of the DSC axis was much less variable than the sound velocity at the axis in both regions. Temporal and spatial variability appear to be equally significant as controls over DSC structure throughout the exercise area.