| This thesis reports on continued development of a new concept for measuring heat transfer between the atmosphere and ocean. The new technique measures net surface heat flux from the aqueous thermal boundary layer. Research includes the first direct, local field comparison of the new method with standard radiometeric measurements and turbulent flux estimates, as well as modeling of the physics at the air-water interface.; Specific development efforts include laboratory calibration of temperature and heat flux sensors, rooftop tank tests characterizing sensor response to incident solar flux and field tests on a local lake evaluating overall performance on a natural water body. Experiments are supplemented by two numerical simulations: (1) a large scale coupled wind-wave model supporting lake data analysis and (2) a small scale air-water interface solar irradiance model.; The current design sensor float demonstrates the ability to accurately measure day and nighttime net surface heat flux in low wind conditions (≤4 m/s). The device is also capable of reasonably accurate sea surface solar irradiance measurements during clear sky, partially cloudy and overcast conditions, also only during light winds.; At higher wind speeds surface gravity waves and foam cause frequent submergence of the sensor elements. The existing submergence detection system does not adequately filter these events. The sensor float has shown the potential to accurately measure fluxes in winds up to 15 m/s. However, this capability depends on avoiding or properly filtering wave-induced submergence events.; Recommendations are made to improve the accuracy of heat flux measurement and improve sensor float dynamic characteristics. While this novel approach to surface heat flux measurement shows promise, additional development effort is necessary. |
