Absolutely referenced geostrophic velocity and transport on a section across the North Atlantic Current

• Published in: Deep-sea research. Part I, Oceanographic research papers Oceanographic research papers, 2000-02, Vol.47 (2), p.309-322
• Main Authors: Meinen, Christopher S, Randolph Watts, D, Allyn Clarke, R
• Format: Article
• Language: English
• Subjects: Absolute transport; Absolute velocity; Acoustic doppler current profiler; ADCP; CTD; Dynamics of the ocean (upper and deep oceans); Earth, ocean, space; Exact sciences and technology; External geophysics; Marine; North Atlantic current; Ocean currents; Oceanography; Physics of the oceans; POGO transport float; Velocity
• ISSN: 0967-0637; 1879-0119
• DOI: 10.1016/S0967-0637(99)00061-8

A transect of CTD profiles crossing the North Atlantic Current (NAC) along WOCE line ACM6 near 42.5°N during August 1–7, 1993, provides geostrophic shear velocity profiles, which were absolutely referenced using simultaneous POGO transport float measurements and velocity measurements from a ship-mounted acoustic doppler current profiler (ADCP). The NAC absolute transport was 112±23×10 6 m 3 s −1, which includes a portion of the transport of the Mann Eddy, a large permanent anticyclonic eddy commonly adjacent to the NAC. The NAC transport estimated relative to a level of no motion at the bottom would have underestimated the true total absolute transport by 20%. A surprisingly large 58×10 6 m 3 s −1 flowed southward just inshore of the NAC. This flow, centered near 1500 dbars about 200 km offshore of the shelf-break, was fairly barotropic with a peak velocity of greater than 20 cm s −1, and the water mass characteristics were of Labrador Sea Water. These absolute transport observations suggest southward recirculation inshore of the NAC at 42.5°N and a stronger NAC than has previously been observed.