A Small-Buoy Based Turbulence and Profile Sampling System: Marine Air-Sea Flux System (MASFlux)

Traditional flux buoys for turbulence measurements have been important platforms for sampling turbulent fluxes near the ocean surface. They are, however, usually large in size and very heavy. Deployment of these buoys are cumbersome and costly. In the past several years, the Meteorology Department of the Naval Postgraduate School have developed a small and easily deployable flux sampling system, the Marine-Air-Sea-Flux System (MASFlux), that is based on a small 19" spar buoy. MASFlux measures turbulence perturbations, mean wind and thermodynamic profiles, surface wave, and upper ocean temperature simultaneously. This system is less than 100 lb and can be easily deployed by two people from a small ship. This presentation will describe the design and instrumentation of the buoy flux measurement system and some of the initial measurements from the MASFlux.

The buoy system has been tested in the Monterey Bay since August 2012 using small vessels, some focused on sensor and buoy performance improvements. In July 2013, the MASFlux was deployed for three days off the coast of Virginia Beach as part of the Trident Warrior 2013 (TW13) field experiment. In six of all these deployments, concurrent measurements of wave and turbulence fluxes in the lower part of the atmospheric boundary layer were made. Some of the results will be discussed here to show the capability of the MASFlux in air-sea interaction related research. The two-dimensional wave measurements from MASFlux were compared with those from the Datawell DWR-G4 wave buoys and showed consistent results in all deployments. Turbulent spectra analyses for data before and after buoy motion correction demonstrate the effectiveness in motion correction for the MASFlux. The spectra from the Monterey Bay deployment revealed a significant amount of energy in the atmospheric turbulence at frequencies of the dominant swell. The mean vertical wind profiles also indicated the effects of swell. These initial measurements and results point to the great potential of the MASFlux for future air-sea-wave interaction study.