In situ and remote sensing signature of meddies east of the mid-Atlantic ridge

• Published in: Journal of Geophysical Research
• Main Authors: Bashmachnikov, Igor, Machín, Francisco, Mendonça, Alexandre de, Martins, Ana María
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union 2009
• Subjects: Meddy; Remote tracking; Northeast Atlantic; Northeastern Atlantic; Mid-Atlantic Ridge
• Online Access: http://hdl.handle.net/10261/15362; https://doi.org/10.1029/2008JC005032

16 pages, 11 figures, 2 tables, supporting information http://onlinelibrary.wiley.com/doi/10.1029/2008JC005032/suppinfo Mediterranean Water eddies (meddies) are thought to play an important climatic role. Nevertheless, their dynamics are not sufficiently known because of difficulties encountered in their observation. Though propagating below the main thermocline, a number of pieces of evidence of sea surface manifestation of meddies are collected. The present work is based on joint in situ and altimetry data analyses to prove that the meddies can be followed with remote sensing data for long periods of time. The in situ observations are based on data from an oceanographic cruise, which crossed three meddies, and reanalysis of historical data sets, including RAFOS floats paths. Suggested methodology permitted us to obtain uninterrupted tracks for several meddies for a period from several months to more than 2 years. It was found that the dynamically calm region to the north of the Azores current presents favorable conditions for meddy tracking. The meddy surface signal may become shattered and difficult to follow during interaction with a strong dynamic structures (the Azores current/surface vortexes) or peaking topography. Theoretical considerations support the observations and lead to the conclusion that the dynamic signature of meddies at the sea surface is an intrinsic property of meddy dynamics The work is accomplished under project OPALINA (PDCTE/CTA/49965/2003), sponsored by the European Space Agency (ESA) and the Foundation for Science and Technology of Portugal (FCT). We would like also to acknowledge the scientific projects DETRA (Regional Direction of Fisheries (DRP)) and LAMAR (Regional Foundation for Science and Technology (DRCT-2.1.2/F/008/2007)). We also thank a postdoctoral fellowship sponsored by DRCT together with Institute of Marine Research (IMAR/DRCT/REF. &D/MED.M1.1.2/008/2005//BPD/002/007) and a doctoral fellowship sponsored by DRCT together with University of the Azores ...