Intense anticyclones at the global Argentine Basin array of the Ocean Observatory Initiative

Abstract. We analyzed physical oceanic parameters gathered by a mooring array at mesoscale spatial sampling deployed in the Argentine Basin within Ocean Observatory Initiative, National Science Foundation major research facility. The was maintained 42∘ S and W, historically sparsely sampled region with small ocean variability, over 34 months from March 2015 to January 2018. data documented four anticyclonic extreme-structure events 2016. structures had different characteristics (size, vertical extension, origin, lifetime Rossby number). They all featured near-inertial waves (NIWs) trapped depth low Richardson values well below mixed layer. Low suggest favorable conditions for mixing. features likely act as mixing pycnocline, bringing heat salt South Atlantic Central Water Antarctic Intermediate Waters. intense were unique 29-year-long satellite altimetry record site. is populated many anticyclones, associated NIWs probably plays an important role setting up upper-water-mass basin.