Directly measured currents and estimated transport pathways of Atlantic Water between 59.5°N and the Iceland–Faroes–Scotland Ridge

• Published in: Tellus A: Dynamic Meteorology and Oceanography
• Main Authors: Katelin H. Childers, Charles N. Flagg, Thomas Rossby, Corinna Schrum
• Format: Article in Journal/Newspaper
• Language: English
• Published: Stockholm University Press 2015
• Subjects: ADCP; current measurements; northeast Atlantic transport patterns; repeat sampling from vessels in regular traffic; Faroes–Shetland Channel; Iceland–Faroes Ridge; Oceanography; GC1-1581; Meteorology. Climatology; QC851-999; Greenland; Reykjanes; Irminger Sea; Hatton Bank; Wyville Thomson Ridge; Wyville-Thomson Ridge; Lousy Bank; George Bligh Bank; Bill Bailey's Bank; Faroes; Iceland; North Atlantic; Northeast Atlantic
• Online Access: https://doi.org/10.3402/tellusa.v67.28067; https://doaj.org/article/4d2f9d8022c644ba9b09b39b6f181534

Using vessel-mounted acoustic Doppler current profiler data from four different routes between Scotland, Iceland and Greenland, we map out the mean flow of water in the top 400 m of the northeastern North Atlantic. The poleward transport east of the Reykjanes Ridge (RR) decreases from ~8.5 to 10 Sv (1 Sverdrup=106 m3 s−1) at 59.5°N to 61°N to 6 Sv crossing the Iceland–Faroes–Scotland Ridge. The two longest ~1200 km transport integrals have 1.4–0.94 Sv uncertainty, respectively. The overall decrease in transport can in large measure be accounted for by a ~1.5 Sv flow across the RR into the Irminger Sea north of 59.5°N and by a ~0.5 Sv overflow of dense water along the Iceland–Faroes Ridge. A remaining 0.5 Sv flux divergence is at the edge of detectability, but if real could be accounted for through wintertime convection to >400 m and densification of upper ocean water. The topography of the Iceland Basin and the banks west of Scotland play a fundamental role in controlling flow pathways towards and past Iceland, the Faroes and Scotland. Most water flows north unimpeded through the Iceland Basin, some in the centre of the basin along the Maury Channel, and some along Hatton Bank, turning east along the northern slopes of George Bligh Bank, Lousy Bank and Bill Bailey's Bank, whereupon the flow splits with ~3 Sv turning northwest towards the Iceland–Faroes Ridge and the remainder continuing east towards and north of the Wyville-Thomson Ridge (WTR) to the Scotland slope thereby increasing the Slope Current transport from ~1.5 Sv south of the WTR to 3.5 Sv in the Faroes–Shetland Channel.