Pan American Climate Study (PACS) mooring recovery and deployment cruise report : R/V Thomas Thompson cruise number 73, 28 November to 26 December 1997

Abstract

Three surface moorings were recovered and redeployed during R/V Thomas Thompson cruise number 73 in the eastern equatorial Pacific as pan of the Pan American Climate Study (PACS). PACS is a NOAA-funded study with the goal of investigating links between sea-surface temperature variability in the tropical oceans near the Americas and climate over the American continents. The three moorings were deployed near 125°W, spanning the strong meridional sea-surface temperature gradient associated with the cold tongue south of the equator and the warmer ocean north of the equator, near the northernmost, summer location of the Intertopical Convergence Zone. The moored array was deployed to improve the understanding of air-sea fluxes and of the processes that control the evolution of the sea surface temperature field in the region. Two surface moorings, located at 3°S, 125°W and lO°N, 125°W, belonging to the Upper Ocean Processes (UOP) Group at the Woods Hole Oceanographic Institution (WHOI), were recovered after being on station for eight months and redeployed. Two eight-month deployments were planned. A third mooring deployed at the equator and 128°W by the Ocean Circulation Group at the University of South Florida (USF) was also recovered and redeployed. The USF mooring, unfortunately, had to be recovered immediately following redeployment due to a problem with the buoy and instrumentation. The buoys of the two WHOI moorings were each equipped with meteorological instrumentation, including a Vector Averaging Wind Recorder (VAWR), and an Improved Meteorological (IMET) system. The WHOI moorings also carried Vector Measuring Current Meters, single point temperature recorders, and conductivity and temperature recorders located in the upper 200 meters of the mooring line. In addition to the instrumentation noted above, a variety of other instruments, including an acoustic current meter, acoustic doppler current meters, bio-optical instrument packages and an acoustic rain gauge, were deployed during the PACS field program. The USF mooring had an IMET system on the surface buoy and for oceanographic instrumentation, two RD Instruments acoustic doppler current profilers (ADCPs), single-point temperature recorders, and conductivity and temperature recorders. Conductivity-temperature-depth (CTD) profiles were made at each mooring site and during the transit between mooring locations. This report describes, in a general manner, the work that took place during R/V Thomas Thompson cruise number 73. A description of the WHOI moored array and instrumentation is provided. Details of the mooring designs and preliminary data from the CTD profies are included.