The Extended Ellett Line Cruise 30th July – 17th August 2012
Who is participating?
Six scientists from the Scottish Association for Marine Science (SAMS), 1 scientist from the National Oceanography Centre (NOC), 8 undergraduate Marine Science students who are doing their degree at SAMS as part of the University of the Highlands and Islands (UHI) and 3 students from NOC will be sailing on the RRS Discovery. Colin Griffiths from SAMS is the Chief Scientist and we will meet them all as this blog gets underway.
What is the Extended Ellett Line?
Between the Scottish continental shelf and Rockall outcrop there is a deep ocean basin called the Rockall Trough. Since 1975, physical oceanographers have been sampling these waters annually at stations along a set line (red on Fig. 1) established by David Ellett from SAMS. In 1996, scientists from SAMS and NOC extended the line to Iceland (green on Fig. 1)
Fig. 1. Extended Ellett Line
Why is it important?
There are complex currents in the north Atlantic, some carrying warm water northwards, some returning cold water southwards and many undersea topographical features which alter the direction of flow. These currents moderate the climate of the UK and western Europe. Each water mass has a unique signature of temperature and salinity which together determine its density. This system is a crucial part of the thermohaline circulation.
Data from recent cruises show that the upper layers of the Rockall Trough during the last 7 years have been warm and salty compared to the long-term (30 year) average. It is important to monitor these patterns as society becomes more concerned about human influences on climate and the quality of the natural environment.
Who pays for it?
The Extended Ellett Line time series is part of the UK climate monitoring strategy and is funded mainly by the Natural Environment Research Council (NERC). For more details on the Ellett Line, the data and Dave Ellett himself see: http://www.noc.soton.ac.uk/obe/PROJECTS/EEL/index.php
