Low-Frequency Fluctuations in the Strait of Gibraltar from MEDALPFX Sea Level Data

Abstract

Dep. Oceanogr., Dalhousie Univ., Halifax, N.S. B3H 4J1, Canada J (Journal-Article) M (Marine) Thirteen months of hourly sea level data from four stations in the Strait of Gibraltar, along with appropriate atmospheric pressure data, are used to investigate tidal and low-frequency fluctuations in the strait. Apparent recording errors in the data weaken a study of the tides on their own, but low-passed and complex demodulated (at M sub(2)) time series show that nonastronomical variations in the alongstrait M sub(2) sea level slope are correlated with the varying phase lag from Tarifa to Gibraltar. More importantly, regression of the low-passed sea level difference across the strait on the varying tidal amplitude suggests that the mean surface inflow is only about 10% different from what it would be in the absence of tides. The most important result of the paper is that the ratio of fluctuations in the first two species is consistent wi...