1. University of Plymouth, School of Earth, Ocean, and Environmental Science, Plymouth PL4 8AA, United Kingdom, University of Southampton, National Oceanography Centre Southampton, School of Ocean and Earth Science, European Way, SO14 3ZH Southampton, United Kingdom, University of Montpellier I and II, CNRS-IRD, UMR Hydrosciences-CCMSE, 34095 Montpellier Cedex 5, France, and Centro de Estudios Avanzados de Blanes (CEAB), Camí de Santa Bárbara, E-17300 Blanes, Spain