Arctic Summer Cloud-Ocean Study
Ocean turbulent fluxes
To measure the turbulent fluxes under the ice, a tower was deployed through the ice some 100 m away from the ship. This data set contains mean temperatures, salinities, horizontal current velocities and turbulent fluxes of heat and salt in the upper ocean mixed layer Turbulence data are obtained using so called Turbulence Instrument Clusters (TICs) at several levels deployed through a hole in the ice. Each TIC comprises an Acoustic Doppler Velocimeter, a 5 Mhz ADVOcean manufactured by Sontek/YSI, that measures 3-D velocity in a small volume close to the tip of the instrument. In addition, each TIC is equipped with a SBE-3 temperature sensor, a SBE-4 conductivity sensor and a SBE-7 micro-conductivity sensor, all manufactured by Seabird Electronics. TIC 2 (at 6 m depth) was setup with a SBE-5 pump for pumped measurements of conductivity and temperature. TIC 3 only contained one single ADVOcean. The figure shows the setup and parameters measured at each depth. Data are sampled at 2 Hz for TIC 1 and TIC 3, while TIC 2 sampled at 8 Hz. After the initial sampling, data are split in 15 min intervals in order to capture the covariance in the turbulent eddies with time scales on the order of minutes. Within each interval, velocity is rotated into a streamline coordinate system and fluctuating parts of temperature, salinity and the three velocity components are found within each interval.
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Photo of the turbulence mast through the ice, holding the under-water mast.