Mean and tidal currents in Baltimore canyon

Abstract

The mean and tidal current fields within Baltimore Canyon and on the shelf and slope around it were observed with instrumented moorings at 12 sites. Currents on the shelf are similar to those observed elsewhere over the northeastern U.S. outer shelf with mean flow southwestward at 10 to 15 cm s−1 parallel to the shelf break. Tidal current velocity in the direction of the major axis of the M2 ellipse over the shelf is about 9 cm s−1. Currents within the canyon are complex. Mean flow near the bottom along the canyon axis is downcanyon at 5 cm s at a depth of 275 m, but upcanyon at 7 cm s−1 at 600‐m depth and negligible at depths of 1000 m and 1500 m. At 50 m above the bottom, mean flow at each of these sites is less than it is at 6 m above the bottom. The M2 tidal currents in the canyon tend to be aligned with topography and have velocities ranging up to 22 cm s−1. Maximum instantaneous current speeds were found near the bottom in the canyon axis with a peak speed for the entire survey of 106 cm s−1 near the bottom at the 275‐m level.