ALBERT

Description: The Extended Ellett Line is a hydrographic section between Iceland and Scotland that is occupied annually by scientists from the National Oceanography Centre (NOC) and the Scottish Association for Marine Science (SAMS), UK. The measurement programme began as a seasonally-occupied hydrographic section in the Rockall Trough in 1975, building on early surface observations made underway from ocean weather ships. In 1996 the section was extended to Iceland, sampling three basins: the Rockall Trough, the Hatton-Rockall Basin and the Iceland Basin. These three basins form the main routes though which warm saline Atlantic water flows northwards into the Nordic Seas and Arctic Ocean. The section crosses the eastern North Atlantic subpolar gyre; as well as the net northward flow there is a large recirculation of the upper layers as part of the wind-driven gyre. During its passage through the region, the warm saline water is subjected to significant modification by exchange of heat and freshwater with the atmosphere. The two deep basins (Rockall Trough and Iceland Basin) contain southward flowing dense northern overflow waters, and Labrador Sea Water in the intermediate layers. The specific objectives of the 2016 Extended Ellett Line cruise are: - To complete the annual Extended Ellett Line CTD section; - To collect water samples for measuring biogeochemical properties including dissolved oxygen, nutrients, carbon & trace metals; - To collect underway measurements of surface currents, surface temperature and salinity, bathymetry, surface meteorology; - To complete epibenthic sled tows at a deep location in the central Rockall Trough; - To capture water column and sea floor video with a downward-looking camera attached to the CTD; - To listen for whales and dolphins with a towed hydrophone; and - To deploy Argo floats provided by the UK Met Office as a contribution to the International Argo Project.