Developments on the Extended Ellett Line

Over the last 10 years we have looked into other methods of contributing to the Extended Ellett Line. Chief among these are Argo floats and gliders.

Argo Floats

Two floats were deployed in October 2005, one in the Rockall Trough and one in the Iceland Basin.

Float 6900387 drifted south from the Rockall Trough and spent most of its life circulating in the area south of the Rockall-Hatton Bank before dying in the Iceland Basin.

In the Iceland Basin, float 6900388 was soon caught in the deep northern boundary current by which it was advected all the way round the subpolar gyre. Nearing the end of its life, it reached the Iceland Basin again in 2010, a journey of five years. It featured as the Argo float of the month in January 2011.

In 2007 a further eight floats were released in the Iceland Basin and in 2010 six floats were deployed along the line, four in the Iceland Basin and two in the Rockall Trough.

Gliders

In the early days of the Ellett Line (or the Anton Dohrn section as it was called then), ship surveys were made four times a year. This provided important information about the seasonal cycle. Such intense monitoring with ships is no longer viable.

In 2008 a seaglider was bought by the Scottish Association for Marine Science (SAMS) as part of the Oceans2025 project. After trials Talisker completed its first mission, crossing the Rockall Trough seven times during winter 2009/2010.

Eventually the glider will be deployed to undertake continuous measurements across the Atlantic from Scotland to Iceland and back.