RRS James Cook Expedition 247, 5-22 May 2023, UK, Multidecadal Research at the Porcupine Abyssal Plain - Sustained Observatory

RRS James Cook Cruise 247 departed Southampton 5th May 2023, operated at L4, part of the Western Channel Observatory (6th May), Whittard Canyon (7th May) and the Porcupine Abyssal Plain Sustained Observatory (PAP-SO) area (8-19th May), arriving back in Southampton 22nd May 2022. The goal of the cruise was to continue time-series observations of the surface ocean, water column, and seafloor at PAP-SO, first studied by NOC (then the Institute of Oceanographic Sciences) in 1985. An additional goal was to service a mooring at Whittard Canyon. These activities are supported by the NERC national capability Climate Linked Atlantic Sector Science (CLASS) project. Other goals were to deploy a series of Met Office biogeochemistry Argo floats, test novel sensors in the water column and on seabed sediments and contribute to the EuroGO-SHIP and APERO programmes. The Met Office Mobilis buoy was successfully recovered and a replacement deployed with a sensor frame at 30m. This was a top section turnaround with a full mooring replacement planned for next year. The sediment traps were successfully recovered and replace at both PAP and the Whittard canyon, samples and sensor data were retrieved and intial analysis presented. A series of water column observation and sampling operations were successfully carried out to full depth with a CTD instrument package. The CTD deployments included pre- and post-deployment calibrations of PAP1 and PAP3 sensors, continuation of water column time series data collection and trials for novel biogeochemistry microfluidic sensors. Transits between locations were used to compare underway sampling and sensor data with satellite observations for the region. Five Met Office Argo floats were deployed and one for the APERO programme. The PAP benthic time series was continued with a seafloor sediment core sampling, amphipod traps and trawl samples, including some core sampling and multibeam mapping outside the main PAP benthic sampling area for consideration of future scientific requirements.