RRS James Cook Cruise JC103, 23 Apr - 03 Jun 2014. RAPID moorings cruise report

This cruise report covers scientific operations conducted during RRS James Cook Cruise 103. The purpose of the cruise was the refurbishment of an array of moorings spanning the latitude of 26.5°N from the Bahamas to the Canary Islands. Cruise JC103 departed from Port of Spain on Wednesday 23rd April 2014, calling twice at Nassau, Bahamas before finally docking in Santa Cruz de Tenerife on Wednesday 3rd June 2014. The moorings are part of a purposeful Atlantic wide mooring array for monitoring the Atlantic Meridional Overturning Circulation and the associated heat transport. The array is a joint UK-US programme and is known as the RAPID-MOCHA array. During JC103 moorings were serviced at sites: WBAL, WBADCP, WB1, WB2, WB2L, WBH2, WB4, WB4L, WB6, MAR0, MAR1, MAR1L, MAR2, MAR3, MAR3L, EB1, EB1L, EBHi, EBH1, EBH1L, EBH2, EBH3, EBH4, EBH4L. Sites with suffix ‘L’ denote landers fitted with bottom pressure recorders, WBADCP is a bottom mounted 75kHz ADCP. At the other sites moorings were equipped with CTDs and current meters. CTDs with oxygen sensors were, for the first time, deployed at WB1, WBH2, and WB4. Additionally two PIES (pressure and inverted echo sounder instruments) were recovered but not re-deployed at sites WBP1 and EBP2. Mooring MAR0 was not able to be recovered but was redeployed. A sediment trap mooring NOGST was also recovered and redeployed for the Ocean Biogeochemistry and Ecosystems Group at the NOCS. CTD stations were conducted throughout the cruise for purposes of providing pre- and post- deployment calibrations for mooring instrumentation and for testing mooring releases prior to deployment. Shipboard underway measurements were systematically logged, processed and calibrated, including: surface meteorology, 5m depth sea temperatures and salinities, water depth, and navigation. Water velocity profiles from 15 m to approximately 800 m depth were obtained using the two vessel mounted Acoustic Doppler Current Profilers (one 75 kHz and one 150 kHz). Six APEX Argo floats supplied by the UK Met Office, were deployed during the cruis