Subinertial Slope-Trapped Waves in the Northeastern Gulf of Mexico

Abstract

Current velocity from moored arrays of acoustic Doppler current profilers (ADCPs) deployed on the outer shelf and slope, south of Mobile Bay in the northeastern Gulf of Mexico, shows evidence of alongslope, generally westward-propagating subinertial baroclinic Kelvin waves with periods of about 16 and 21 days, amplitudes of 5?10 cm s?1, and wavelengths of about 500 km. The observed waves were highly coherent over the slope between about 200 and 500 m and accounted for a significant amount of the current variability below 200 m. The source of the waves could be attributed to effects of the Loop Current on the west Florida slope but is more likely due to direct forcing by Loop Current?generated eddies impacting the experimental area.