Recovering EPOC sensors from the subtropical North Atlantic

Preparations are underway for the next RAPID programme research cruise (DY174) at the North Atlantic’s eastern boundary, just south of the Canary Islands. Next week (28 March 2024), the team will depart Santa Cruz de Tenerife on the UK’s research vessel RRS Discovery to recover and redeploy moorings and sensors, with data collected to be used in the update of the timeseries of the strength of the AMOC at 26°N.

For the first time however, over 20 EPOC biogeochemical sensors will also be recovered, including 10 novel Lab-on-chip chemical sensors that have been measuring seawater pH, nitrate, phosphate and alkalinity since February 2022. The sensors will be evaluated for stability and accuracy, and it is hoped the data collected will be used to improve our estimates of the large-scale transports of carbon and nutrients by the AMOC, additionally capturing the non-dynamically-driven variability in their concentrations.

Location map showing RAPID moorings in the North Atlantic
Location of moorings from which EPOC biogeochemical sensors are due to be recovered during RAPID 2024 eastern subtropical North Atlantic cruise.
Schematic showing AMOC moorings and nitrate concentrations at 26N
Schematic of the Atlantic meridional overturning circulation and the RAPID mooring array, and nitrate hydrographic distribution at 26°N. Image courtesy Pete Brown & Simon Beasley

Some of the sensors will be refurbished for redeployment in 2025. The new knowledge gained will be shared at a cross-community workshop in mid-2025, bringing together biogeochemists, physical oceanographers and technologists to discuss how best to use integrate biogeochemical measurements with transport mooring arrays.

For cruise updates follow: https://twitter.com/RAPID_AMOC

Deployment of EPOC sensors in 2022
EPOC sensors being deployed on the RAPID cruise DY146 in February 2022. Image courtesy Clara Douglas
Deployment of EPOC sensors in 2022
EPOC sensors being deployed on the RAPID cruise DY146 in February 2022. Image courtesy Sara Fowell
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EPOC is funded by the European Union. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union. Neither the European Union nor the granting authority can be held responsible for them.

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