RRS Discovery Cruise 223, 28 Sep-19 Nov 1996. VIVALDI ‘96

Abstract

RRS Discovery Cruise 223, VIVALDI ‘96, was a contribution to the UK WOCE Community Research Programme. The pattern of SeaSoar sections was designed to enable the upper ocean circulation in the Subpolar gyre of the North Atlantic to be mapped and in particular the course of the North Atlantic and Irminger Currents within the region to be determined. The sparse deep CTD survey was required to complement the upper ocean survey and provide estimates of total mass transport and an ‘oceanographic opinion poll’ of water mass properties, including CFCs. The cruise commenced by repeating the well-established Rockall Trough CTD Section from Barra Head to Rockall Island. This was then extended north to Lousy Bank from where a CTD section measured before by Saunders across the Iceland Basin was repeated. From then onwards the cruise consisted principally of SeaSoar/ADCP sections interspersed with deep CTD casts (see track plot, Fig.1). These were placed on the ‘Vivaldi Grid’ (round 3° of latitude and multiples of 300 km west of 20°W) where possible, though the complex topography was taken into account. East of Greenland a more intense CTD section of 6 stations (12995-13001) was made along 60°N to cut the East Greenland Current. In addition 7 profiling floats were deployed in the Irminger Basin