RAFOS float trajectories in Meddies during the Semaphore Experiment, 1993-1995

Abstract

As part of the Semaphore Experiment four Meddies (Mediterranean Water Eddies) were discovered in the Canary Basin and tracked with freely drifting RAFOS floats. An additional Meddy was discovered off Lisbon by Pingree (1995) and also tracked with RAFOS floats. One large and energetic Meddy, discovered 1700 km west of Cape St. Vincent, Portugal, set a distance and speed record as it translated another 1700 km southwestward at 3.9 cm/sec during the 1.5 years. This Meddy traveled 57% of the distance from Cape St. Vincent toward the spot McDowell and Rossby (1978) found a possible Meddy north of the Dominican Republic. Four Meddies collided with tall seamounts which seemed to disrupt the normal swirl velocity perhaps fatally in three cases. One Meddy appeared to bifurcate when it collided with seamounts. This report describes the float trajectories in the Meddies and summarizes the main results.