THE CIRCULATION AND HYDROGRAPHY OF CONCEPTION BAY, NEWFOUNDLAND

The hydrography and circulation of Conception Bay (Newfoundland) are described based on hydrographic, current-meter and drifter data collected over four years (1988-1991). The seasonal cycles of temperature (-1.6 to 13-17 degrees C) and salinity (31-32.5) in the bay closely follow those on the adjacent shelf Exchange of bottom water was observed in April 1989. Deepwater exchange was observed from late fall to early winter of 1989-90. Tidal currents are weak, 1-2 cm s(-1) for the M(2) and K-1 constituents. Observed Eulerian mean currents (<3 cm s(-1)) are smaller than the standard deviation (1-11 cm s(-1)); however, there is a persistent outflowing current of 10 to 20 cm s(-1) within 2 km of the shoreline on the eastern side of the outer bay. The Lagrangian correlation length scale is from 4 to 10 km, in agreement with the weak coherence squared (less than or equal to 0.4) found between the fixed current-meter sites separated by greater than 4-5 km. The variable currents (up to 20 cm s(-1)) tend to be cyclonic. Cyclonic eddies were observed near the mouth on the eastern ems side of the bay, adjacent to the outflow A simplified fractal dispersion model gives residence dimes of 42 d similar to those obtained from a scaling analysis (30-40 d) and a diagnostic numerical model (30 d).