FN Archimer Export Format PT J TI Evolution of an oceanic anticyclone in the lee of Madeira Island: In situ and remote sensing survey BT AF CALDEIRA, Rui M. A. STEGNER, Alexandre COUVELARD, Xavier ARAUJO, Isabel B. TESTOR, Pierre LORENZO, Alvaro AS 1:1,2;2:3,4;3:2,5;4:1;5:6;6:7; FF 1:;2:;3:PDG-ODE-DYNECO-PHYSED;4:;5:;6:; C1 Univ Porto, CIIMAR Interdisciplinary Ctr Marine & Environm Re, P-4100 Oporto, Portugal. Univ Madeira, CCM Ctr Math Sci, Funchal, Portugal. Ecole Polytech, Meteorol Dynam Lab, F-75230 Paris, France. ENSTA , UME,Ctr Yvette, Paris, France. Ifremer, Lab Phys Oceans, Plouzane, France. Univ Paris 06, Lab Oceanog & Climat, LOCEAN IPSL, Paris, France. PLOCAN Plataforma Ocean Canarias, Las Palmas Gran Canaria, Canary Islands, Spain. C2 UNIV PORTO, PORTUGAL UNIV MADEIRA, PORTUGAL ECOLE POLYTECH, FRANCE ENSTA, FRANCE IFREMER, FRANCE UNIV PARIS 06, FRANCE PLOCAN, SPAIN SI BREST AUTRE SE PDG-ODE-DYNECO-PHYSED AUTRE IN WOS Ifremer jusqu'en 2018 copubli-france copubli-europe copubli-univ-france TC 26 UR https://archimer.ifremer.fr/doc/00197/30846/29209.pdf LA English DT Article DE ;boundary-layer;inertial instability;mode water;mixed layer;intrathermocline eddies;wake AB Island wakes are areas of a strong eddy activity influencing the availability and transport of organic matter in the ocean which, in turn impact biological productivity. Despite this, eddy formation in the lee of North Atlantic tropical islands is scarcely documented, except for the Canary Islands. Moreover, the occurrence of anticyclones leeward of Madeira has seldom been detected. During the summer of 2011, a multiplatform approach, combining satellite data with in situ measurements, was used to study an anticyclonic eddy generated in the lee of the Madeira Island. The main objective was to confirm recent numerical evidence suggesting that orographically perturbed winds can induce anticyclonic eddies leeward of Madeira, particularly during summer months. The high resolution sampling of the eddy's interior shows a strong downwelling of approximate to 100 m of the isopycnal layer below the mixed layer, typical of intrathermocline eddies. The 25 km radius of this anticyclonic structure exceeds the local deformation radius by a factor of 2. The vortex Rossby number remained moderate (Ro=0.26) even if the relative core vorticity reached a finite value (zeta/f = -0.7). The occurrence of strong trade winds (10-15 m s(-1)) prior to the detection of the first surface eddy signatures (July 2011) concurrent with opposite flowing geostrophic currents, shows that the orographic wind forcing is the main mechanism for generating this mesoscale long-lived eddy. After leaving the shelter of the island, the eddy traveled northwesterly following a perpendicular net Ekman transport pathway at a speed of 5 km/d, for at least 2 months. An interaction with a cyclonic partner generated in the area helped precipitate the northward trajectory. This study presents the first clear evidence of a wind-induced mesoscale anticyclone in the lee of Madeira. PY 2014 PD FEB SO Journal Of Geophysical Research-oceans SN 0148-0027 PU Amer Geophysical Union VL 119 IS 2 UT 000336261200034 BP 1195 EP 1216 DI 10.1002/2013JC009493 ID 30846 ER EF