Glider on its way to the deployment site west of Tiree, Scotland (left); about to be launched for trials in the Lynn of Morvern (middle); and close-up on the glider sensors (right).

Link to MISSION 1 and the first operational deployment of a ocean glider from UK waters

The climate of western Europe is generally believed to be moderated by the circulation of the major currents in the North Atlantic.  Our understanding of these currents, and how they change over timescales of years to decades and longer, has developed from longterm in situ observations of temperature and salinity in the Atlantic Ocean.  Additional monitoring of the environmental condition of the Atlantic requires regular measurements of biogeochemical parameters such as dissolved oxygen, nutrients, chlorophyll and particulate organic carbon.  The value of such measurements has become very apparent in recent years as society becomes increasingly concerned about the anthropogenic influences on climate and the quality of the natural environment.

Under the leadership of Dave Ellett, SAMS initiated the regular monitoring of the Rockall Trough in 1975.  In 1996 the National Oceanography Centre, Southampton joined SAMS in extending the line from Rockall to Iceland, so that one of the major gateways for exchange between the Nordic Seas and the North Atlantic could be monitored.

Originally the Ellett Line was sampled up to four times a year making it possible to monitor seasonal changes, as well as reducing the statistical variability inherent in individual sections. This heavy use of ship time is no longer viable, and to increase the frequency of our observations we are trialling the use of an ocean going Seaglider, an autonomous vehicle that will be deployed from the Scottish coast to undertake continuous measurements across the Atlantic to Iceland and back in 2009.

In September 2008 we took possession of our first Seaglider, Talisker.  In February 2009 it was deployed in Loch Linnhe for 24 h where it undertook a successful overnight trial.  On October 12 2009 Talisker was launched at 56 30' N, 7 30' W, 15 miles west of Tiree, the first operational glider deployment to be made in British waters.

Talisker is equipped with standard CTD, DO, backscatter and fluorescence sensors, and will profile the upper 1000m of the water column observing the seasonal signal and relaying real-time data to Dunstaffnage. It uses GPS position fixing to determine where it is and communicates with a pilot back at base using an Iridium link.   The glider pilot receives position, scientific and internal performance data and based on this can instruct the glider on waypoints to aim for during its mission. Although limits in depth range, sensor availability and power supply mean that it will supplement rather than fully replace the ship borne observations, the novel use of glider to monitor the state of the Atlantic opens up huge opportunities not only for understanding the state of the ocean, but also for undertaking new research that will build on our ability to predict future climate states.

Technical note for other glider users (Aug 2009):  Until recently we were trying to use the RUDICS gateway to communicate with the glider.  This has proved technically difficult and we have now converted back to using a BT analogue phone line via SAMS digital network.

For further information contact Toby Sherwin

See also:

The European Gliding Observations website

Seaglider Fabrication website

iRobot website