CRUISE REPORT: A05 (Updated JUL 2010)
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CRUISE REPORT: A05 (Updated JUL 2010) HIGHLIGHTS Cruise Summary Information WOCE Section Designation A05 Expedition designation (ExpoCodes) 74DI20040404 Chief Scientist Stuart Cunningham/SOC-JRD Dates Apr 4, 2004 - May 10, 2004 Ship RSS Discovery Ports of call Santa Cruz de Tenerif - Freeport, Grand Bahama 27° 54' N Geographic Boundaries 79° 56' W 13° 22' W 24° 29' N Stations 125 Floats and drifters deployed 1 Argo float deployed Moorings deployed or recovered 0 Chief Scientist Contact Info.: Stuart Cunningham • National Oceanography Centre University of Southampton Waterfront Campus • European Way, Southampton SO14 3ZH Phon: +44 (0) 23 8059643 • Email: [email protected] 1 Links to Select locations Shaded sections are not relevant to this cruise or were not available when this report was compiled Cruise Summary Information Hydrographic Measurements Description of Scientific Program CTD Data: Geographic Boundaries Acquisition Cruise Track (Figure): PI CCHDO Processing Description of Stations Calibration Description of Parameters Sampled Temperature Pressure Bottle Depth Distributions (Figure) Salinities Oxygens Floats and Drifters Deployed Bottle Data Moorings Deployed or Recovered Salinity Oxygen Principal Investigators Nutrients Cruise Participants Carbon System Parameters CFCs Problems and Goals Not Achieved Helium / Tritium Other Incidents of Note Radiocarbon Underway Data Information References Navigation Bathymetry Highlights Acoustic Doppler Current Profiler (ADCP) Salinity Analysis Thermosalinograph Autoflux XBT and/or XCTD Carbon System Parameters Meteorological Observations Atmospheric Chemistry Data Data Report Processing Notes Acknowledgments 2 A05 • 2004 • Station Locations • Cunningham • RSS Discovery 3 SOUTHAMPTON OCEANOGRAPHY CENTRE CRUISE REPORT NO. 54 RRS Discovery Cruise 279 04 APR - 10 MAY 2004 A Transatlantic Hydrographic Section at 24.5°N Dr. Stuart A. Cunningham 2005 James Rennell Division for Ocean Circulation and Climate Southampton Oceanography Centre University of Southampton Waterfront Campus European Way Southampton Tel: +44 (0)23 8059 6436 Hampshire SO14 3ZH Fax:+44 (0)23 8059 6204 UK Email: [email protected] 4 ABSTRACT The cruise report describes the acquisition and processing of transatlantic hydrographic, current, chemistry and other measurements made during three cruises in Spring 2004 at a latitude of around 24.5°N from shallow water near Africa to shallow water just off Palm Springs beach on the eastern seaboard of the USA. During the principal cruise, RRS Discovery Cruise D279 (4th April to 10th May 2004), 125 full depth CTD and lowered acoustic Doppler current profiler (LADP) stations were completed between the USA and Africa and continuous underway observations were made of currents in the upper 1000m using a ship mounted 75kHz ADP and of surface salinity and temperature. At each station up to 24 water samples were captured for the analysis of oxygen, salinity, nitrate, silicate, phosphate, CFC11, 12, 113 and CCl4 (carbon tetrachloride), discrete total inorganic carbon (TCO2), discrete total alkalinity (TA) and, discrete partial pressure of CO2 (discrete pCO2). Direct, near real-time measurements of the air-sea turbulent fluxes of momentum and sensible and latent heat in addition to various mean meteorological parameters including testing of a new Licor sensor to determine its suitability for making direct measurements of the air-sea CO2 flux were also made. Atmospheric dust samples were gathered on a daily basis. Two prior cruises D277 (26th February to 16th March) and D278 (19th to 30th March) completed 33 full depth CTD/LADP stations in the Florida and Deep Western Boundary Currents, including continuous underway observations of currents in the upper 1000m and of surface salinity and temperature. No LADP or chemistry measurements were made during these cruises. The three cruises provide one CTD and one CTD/LADP transect of the Florida Current, two Florida Current transects at 5knots with the shipboard ADP continuously seeing to the bottom for high accuracy well resolved direct velocity measurements, one section of 16 CTD stations across the Deep Western Boundary Current and a 125 station transatlantic section with a full suite of physical and chemical measurements. The principal scientific objective is to estimate the circulation across 24.5°N, using for the first time, LADP profiles at each station as constraints in an inverse study. Using this circulation and the transatlantic distribution of temperature and other properties we will calculate the Atlantic heat and property fluxes. We will also define the size and structure of the Atlantic Meridional Overturning Circulation (MOC) to compare to results from a recently deployed transatlantic mooring array designed to continuously measure the size and structure of the MOC. The 24.5°N section has now been occupied five times since 1957 (including the 2004 section reported here). Therefore, we will analyse temporal trends of temperature to see if the widely report warming of the thermocline and intermediate waters and cooling of deep water is continuing. Carbon measurements were also obtained in 1992 and 1998 so this section provides a unique decadal view of anthropogenic carbon fluxes. 5 KEYWORDS CTD, ADCP, METEROLOGY, NUTRIENTS, CFC, CARBON TETRACHLORIDE, CARBON, ATLANTIC, CIRCULATION, MERIDIONAL OVERTURNING CIRCULATION, LOWERED ADCP, SHIPBOARD ADCP, OCEAN SURVEYOR, ATMOSPHERIC CHEMISTRY, D278, D278, D279, OXYGEN 6 CONTENTS Scientific Personnel Ship’s Personnel Acronynms Acknowledgements 1. Introduction 2. Scientific Background 3. Objectives 4. Basic Observational Strategy 5. Itinerary 6. Narrative 7. D279 Bridge Timetable Of Events 8. Ctd Operations – D279 9. Ctd Data Processing And Calibration 10. Sbe35 Deep Ocean Standards Thermometer 11. Water Sample Salinity Analysis 12. Winches 13. Adcp And Battery Pack 14. Lowered Acoustic Doppler Current Profiler 15. Lowered Acoustic Doppler Current Profiler Data Processing Software Test Suite 16. Navigation And Shipboard Acoustic Doppler Current Profiler 17. Ashtech 3df Gps Attitude Determination 18. Ocean Surveyor 75khz Shipboard Acoustic Doppler Current Profiler 19. 150khz Shipboard Acoustic Doppler Current Profiler 20. Measurement Of Dissolved Oxygen 21. Measurement Of Nutrients 22. Autoflux - The Autonomous Air-Sea Interaction System 23. Surface Met Data 24. Salinity Calibration Of Underway Data 25. Bathymetry 26. Shipboard Instrumentation And Computing 27. Carbon Parameters (Cbn) 28. Halocarbons 29. Atmospheric Sampling 30. Trial Float Deployment 31. Dissolved Oxygen Microelectrode Sensor 7 SCIENTIFIC PERSONNEL D277, 26th Feb to 16th March 2004 Principally a moorings deployment cruise {Cunningham, 2005 #1247} but including a CTD/LADP and SADP section across the Florida Current at 27°N between 79° 12.23’W and 79° 51.89’W and a SADP section across New Providence Channel to measure the transport of water flowing west into the Florida Current. Table 1: D277 scientific and technical personnel. Stuart Cunningham PS (SOC) Darren Rayner Scientist (SOC) Pedro Vélez Belchi Scientist (IEO) Stephen Whittle OED Ian Waddington OED John Wynar OED Robert McLachlan OED Elizabeth Rourke OED Christian Crow OED Peter Keen OED 10 persons 8 D278, 19th March to 30th March 2004 Principally a moorings deployment cruise {Cunningham, 2005 #1247}) but including a CTD/LADP and SADP section along the Abaco Mooring Array at 26.5°N between 71° 58.12’W and 76° 53.67’W to measure properties and transport of the Deep Western Boundary Current. Table 2: D278 scientific and technical personnel. Stuart Cunningham PS, SOC Darren Rayner SOC Harry Bryden SOC Marc Lucas SOC Jochem Marotzke MPI Johanna Baehr MPI Clotilde Dubois MPI Fiona McLay MPI Bill Johns UoM Lisa Beal UoM Deb Shoosmith UoM Mark Graham UoM Robert Jones UoM Ian Waddington OED John Wynar OED Robert McLachlan OED Christian Crow OED Jeffrey Benson OED Jeffrey Bicknell OED Chris Hunter OED 20 persons 9 D279, 4th April to 12th May, 2004 Transatlantic hydrography. Table 3: D279 scientific and technical personnel. Stuart Cunningham PS SOC Louise Duncan PI LADP SOC Steve Alderson PI SADP, Nav SOC Hannah Longworth PI CTD, Salts, Samples SOC Rachel Hadfield PI Underway obs SOC Amanda Simpson PI Bathymetry SOC Margret Yelland PI Autoflux SOC Robin Pascal Autoflux SOC Richard Sanders PI Nutrients, Oxygen SOC Abigail Pattenden Oxygen SOC Angela Landolfi Nutrients, Oxygen SOC Rhiannon Mather Oxygen SOC Ute Schuster PI Carbon UEA Gareth Lee Carbon UEA Maria Nielsdottir Carbon UEA David Cooper PI CFC UoM Charlene Grail CFC UoM David Teare PI CTD technical OED Peter Keen CTD OED Martin Bridger TLO OED Richard Phipps Mechanical OED 21 persons 10 Table 4: D279 watches (watch leader in bold). Physics 0800-1600 1600-2400 0000-0800 Louise Duncan Robin Pascal Richard Sanders Hannah Longworth Margret Yelland Steven Alderson Rachel Hadfield Amanda Simpson CTD Technical 1200-1600 1600-0200 0200-1200 Martin Bridger Peter Keen David Teare Oxygens and Nutrients 0800-1600 1600-2400 0000-0800 Angela Landolfi Abigail Pattenden Richard Sanders Rhiannon Mather Carbon 0800-1600 1600-2400 0000-0800 Maria Nielsdottir Ute Schuster Gareth Lee CFCs 1400-0200 0200-1400 David Cooper Charlene Grail 11 SHIP’S PERSONNEL Table 5: Ship’s personnel for D277, D278 and D279. Rank D277 D278 D279 Master Roger Chamberlain Roger Chamberlain Roger Chamberlain Chief Officer Derek Noden Richard Warner Richard Warner 2nd Officer John Mitchell Phil Oldfield Phil Oldfield 3rd Officer Annalaara K-Willis Darcy White