The Extended Ellett Line (EEL) is a full-depth hydrographic section between Scotland, Rockall, and Iceland. It is designed to capture the shallow, warm inflow into the subpolar gyre and the Nordic Seas and the deep, cold return flow that contributes to the lower branch of the Atlantic Meridional Overturning Circulation. The objective is to make an annual occupation of the EEL section and create a time series of the evolution of the Northeast Atlantic. The Ellett Line has been occupied since 1975 and its extension since 1996, making it one of the longest-running
deep-ocean annual repeat hydrographic sections.
Data from the EEL are delivered to BODC within a year of collection and from there they are available to the community. Results are reported via the EEL website
http://prj.noc.ac.uk/ExtendedEllettLine/home and through an annual report. Furthermore, the EEL is an ICES standard section and data are incorporated into the
ICES annual climate report, the Climate Impacts Annual Report Card by UK Marine Climate Change Impacts Partnership, and the Charting Progress reports published by DEFRA.
The annual CTD hydrographic section from Scotland to Iceland consists of approximately 75 full depth stations requiring 14 days to complete, including time for bad weather contingency. In addition to the primary goals of measuring temperature, salinity, oxygen, nutrients, velocity, and carbon parameters, there may be other, opportunistic, data collection for gases (underway sampling) and trace metals (samples taken from the extra water in the Niskin bottles). Furthermore, given that this area is a hotspot of glider activity, there may be opportunistic glider recoveries or deployments.