Tidal and long-term volume transport through Jewfish Creek, Florida Keys

A 14-mo current meter record together with channel calibration measurements are used to investigate the dynamics of long-term volume transport through Jewfish Creek, the main channel connecting Blackwater Sound in northeastern Florida Bay with Barnes Sound, a southern extension of Biscayne Bay. Seasonal variations dominate the longterm flow through this channel as water generally flows into Blackwater Sound during fall, winter and early spring months, then out of the sound in late spring and summer. Low-frequency reversals occur over time scales of several days to about 2 wks throughout the study period. Flow into or out of Florida Bay typically averaged +/-30-50 m(3) s(-1) over these time scales. Low-frequency motions account for 80% of the total variance in along-channel volume transport. Harmonic analysis quantifies the amplitude of the dominant M-2 tidal constituent at 27 m(3) s(-1) and over half of any M-2 tidal cycle 380 x 10(3) m(3) of water moves past the study site. Water level records indicate that the tidal transport is forced by Atlantic tides entering Barnes Sound through Biscayne Bay; Blackwater Sound is virtually tideless. Low-frequency flow through the channel is driven by a broad range of wind stress components acting to create water level differences between the two subbasins. Water level is most responsive to the 030-210 degrees wind stress component and over all time scales between about 2 d and 4 wks this component of wind stress accounts for 50-85% of the total variance in water level differences between Barnes Sound and Blackwater Sound. These water level differences explain 88% of the variance in low-frequency flow through Jewfish Creek.