A census of Meddies tracked by floats

Recent subsurface float measurements in 27 Mediterranean Water eddies (Meddies) in the Atlantic are grouped together to reveal new information about the pathways of these energetic eddies and how they are often modified and possibly destroyed by collisions with seamounts. Twenty Meddles were tracked in the Iberian Basin west of Portugal, seven in the Canary Basin. During February 1994 14 Meddles were simultaneously observed, 11 of them in the Iberian Basin. Most (69%) of the newly formed Meddles in the Iberian Basin translated southwestward into the vicinity of the Horseshoe Seamounts and probably collided with them. Some Meddles (31%) passed around the northern side of the seamounts and translated southwestward at a typical velocity of 2.0 cm/s into the Canary Basin. Some Meddles observed there were estimated to be up to similar to 5 yr old. Four Meddles in the Canary Basin collided with the Great Meteor Seamounts and three Meddles were inferred to have been destroyed by the collision. Overall an estimated 90% of Meddles collided with major seamounts. The mean time from Meddy formation to a collision with a major seamount was estimated to be around 1.7 yr. Combined with the estimated Meddy formation rate of 17 Meddies/yr from previous work, this suggests that around 29 Meddles co-exist in the North Atlantic. Therefore during February 1994 we observed about half of the population of Meddles. (C) 2000 Elsevier Science Ltd. All rights reserved.