Measurement of net ocean surface heat flux, solar irradiance and temperature during the CBLAST-Low field program using a novel surface contact multi-sensor float

A light, wave-following float which simultaneously measures net surface heat flux, solar irradiance and water temperature will be described. The multi-sensor float (MSF) is designed such that two thin flux plates are positioned within the aqueous thermal conductive sublayer at the air-sea interface. Each flux plate has different solar absorption characteristics allowing the component of solar irradiance to be distinguished from net heat flux. Each flux plate also has an embedded thermocouple for skin-temperature measurement. MSF's are deployed tethered to a World Ocean Circulation Experiment (WOCE)-type drifter buoy.

This talk will discuss float and drifter buoy performance during a series of short-term deployments at the Martha's Vineyard Coastal Observatory (MVCO) during the August 2003, ONR sponsored CBLAST-Low field experiment as well as previous deployments and calibration tests. Net flux, solar irradiance and surface temperature measured by this novel instrument are compared with turbulent and radiative surface fluxes measured and derived from moored IMET buoy and MVCO Air-Sea Interaction Tower data using standard measurement techniques. Buoy/MSF measurements of dynamical properties, such as subsurface current and dominant wave period, are compared to data available from the MVCO underwater node and drifting buoys.

This new instrument is presently capable of characterizing the thermal physics at the air-sea interface, especially in low wind conditions. With continued development, we anticipate our buoy system could be deployed in association with moored buoy networks and drifter buoy programs to provide longer-term data for oceanographic, marine meteorology and climate studies.