RRS James Cook Cruise JC031, 03 Feb-03 Mar 2009. Hydrographic sections of Drake Passage

Repeat hydrographic sections (WOCE sections SR1 AND SR1b) were occupied in Drake Passage during February - March 2009 aboard the RRS James Cook (JC031). The primary objective of this cruise was to measure ocean physical, chemical and biological parameters in order to establish regional budgets of heat, freshwater and carbon. A total of 84 CTD/LADCP stations were sampled across Drake Passage. In addition to temperature, salinity and oxygen profiles from the sensors on the CTD package, water samples from a 24-bottle rosette were analysed for salinity, dissolved oxygen and inorganic nutrients at each station. Water samples were collected from strategically selected stations and analysed onboard ship for SF6, CFC’s, pCO2, TIC, alkalinity, and phytoplankton. Some bottle and underway samples were analysed for Ar/O ratios. In addition, salinity samples were collected and analysed from the ships’ underway system to calibrate and complement the data continually collected by the TSG (thermosalinograph). Full depth velocity measurements were made at every station by an LADCP (lowered acoustic Doppler current profiler) mounted on the frame of the rosette. Throughout the cruise, velocity data in the upper few hundred metres of the water column were collected by the ships’ VMADCP (vessel mounted acoustic doppler current profiler) mounted on the hull. Meteorological variables were monitored using the onboard surface water and meteorological sampling system (SURFMET). This report describes the methods used to acquire and process the data on board the ship during cruise JC031.