Ferry observations on temperature, salinity and currents in the marsdiep tidal inlet between the North Sea and Wadden Sea

Publisher Summary This chapter discusses the observation made by a ferry on temperature, salinity, and currents in the Marsdiep tidal inlet between the North Sea and Wadden Sea. In a cooperation between Netherlands Institute for Sea Research and the ferry company, Texels Eigen Stoomboot Onderneming (TESO), continuous observations from the ferry—Schulpengat—are carried out in the Marsdiep tidal inlet between the North Sea and Dutch Wadden Sea. The measurements include surface temperature, salinity, and fluorescence as obtained from a through-flow system, as well as vertical profiles of velocity and echo-intensity, obtained every 2 s with an acoustic Doppler current profiler mounted below the hull of the ferry. A dedicated computer onboard the ferry combines and stores the data from an acoustic doppler current profiler (ADP), the through-flow system, and the DGPS and GYRO system. Part of the data is presented directly on a screen in the passenger's room of the ferry. The chapter presents a figure showing daily averages of salinity and temperature observations obtained in 1998. The temperature observations clearly show the seasonal variability in surface heating. It has been found that on this time scale, the temporal variations in salinity mainly reflect the temporal variability of the fresh water discharge to the Wadden Sea and, more indirectly, the fresh water discharge to the coastal zone by rivers south of the inlet.