Tidal Variability of SST Frontal Locations on Georges Bank, 1986-1989

Timothy P. Mavor and James J. Bisagni

Sea surface temperature (SST) fronts, determined from AVHRR data, are examined in the Georges Bank region for a 4 year (1986-1989) time period. The AVHRR images were processed first by a multi-image cloud-clearing algorithm. The declouded images were then passed through an edge-detection algorithm. The resulting frontal locations clearly show the tidal mixing front near the 50 m isobath on Georges Bank, as well as the presence of a persistent front near the shelf break. Preliminary work on the detected frontal locations indicates the advection of the mean position of the tidal mixing front over the period of a tidal cycle. Seasonal variations in the position of SST fronts in the Georges Bank region also show the summer development of the tidal mixing front. Determination of the mean and seasonal variation for the frontal locations will help in the calculation of probable areas of off and on-bank flow.