The Subduction Experiment. Cruise Report, R/V Oceanus, Cruise Number 250 Legs 1 and 2. Subduction 2 Mooring Deployment and Recovery Cruise, 25 January-26 February 1992

Subduction is the mechanism by which water masses formed in the mixed layer and near the surface of the ocean find their way into the upper thermocline. The subduction process and its underlying mechanisms were studied through a combination of Eulerian and Langrangian measurements of velocity, measurements of tracer distributions and hydrographic properties and modeling. An array of five surface moorings carrying meteorological and oceanographic instrumentation were deployed for a period of two years beginning in June 1991 as part of an Office of Naval Research ONR funded Subduction experiment. Three eight month deployments were planned. The initial deployment of five surface moorings took place during the third leg of RV Oceanus cruise number 240. The moorings were deployed at 18 deg N 34 deg W, 18 deg N 22 deg W, 25.5 deg N 29 deg W, 33 deg N 22 deg W and 33 deg N 34 deg W. A Vector Averaging Wind Recorder VAWR and an Improved Meteorological Recorder IMET collected wind speed and wind direction, sea surface temperature, air temperature, short wave radiation, barometric pressure and relative humidity. The IMET also measured precipitation. The moorings were heavily instrumented below the surface with Vector Measuring Current Meters VMCM and single point temperature recorders. Expendable bathythermograph XBT data were collected and meteorological observations were made while transitting between mooring locations. This report describes the work that took place during RV Oceanus cruise 250 which was the second scheduled Subduction mooring cruise. During this cruise the first setting of the moorings were recovered and redeployed for a second eight month period.... Air-sea interaction, Moored instruments, Subduction.