RRS James Cook Cruise JC191 19 January - 1 March 2020 Hydrographic sections from the Florida Straits to the Canaries Current across 24ºN in the Atlantic Ocean

• Main Author: Sanchez-Franks, Alejandra
• Format: Report
• Language: English
• Published: National Oceanography Centre 2020
• Subjects: Mid-Atlantic Ridge; Western Basin; North Atlantic
• Online Access: http://nora.nerc.ac.uk/id/eprint/528224/; https://nora.nerc.ac.uk/id/eprint/528224/1/Cruise_Rep_70S.pdf

A hydrographic section across the North Atlantic Ocean at a nominal latitude of 24°N was occupied by the RRS James Cook (cruise identifier: JC191) from 19 January to 1 March, 2020. The ship departed from Port Everglades, USA, completing a total of 135 CTD stations over the Florida Straits, the western basin, Mid-Atlantic Ridge, eastern basin and eastern boundary up to Morocco, before ending the cruise in Santa Cruz de Tenerife, Spain. The main objectives of the JC191 research expedition was to collect/measure physical-, chemical-, and biological-ocean data with the purpose of estimating heat, freshwater and carbon budgets on low frequency time scales. All CTD stations had measurements from a CTD rosette equipped with temperature, conductivity, pressure, oxygen sensors, in addition to water captured from 24 niskin bottles fired at varying intervals throughout the full depth water column. The water from the niskin bottles was analysed for dissolved oxygen, carbon (DIC/TA), nutrients, and conductivity. Water for methane (CH4), C14, C13, and pigments (filtered) was collected for onshore analysis. The CTD rosette was also equipped with 2 RBR loggers measuring conductivity, temperature and pressure (up to 6,000m), and a lowered Acoustic Doppler Current Profiler (LADCP) making full depth velocity measurements. The 135 CTD stations include 2 carbon blank stations, and 2 bulk water stations for incubations. In addition to the CTD stations, the RRS James Cook has an underway system, which includes an intake for surface water to be pumped into the water bottle annex and the deck lab; two vessel mounted ADCPs (VMADCPs). A thermosalinograph and a fluorometer, installed in the water bottle annex, continually recorded conductivity, temperature and fluorescence. Water from the CTD was collected to calibrate the ship’s underway TSG. The VMADCPs, 75Hz and 150HZ, mounted on the drop keel record ocean velocities in roughly the top 300- and 600-m, respectively. Surface carbon and methane measurements were also recorded from the ...