Measurement of currents in enclosed blackish waters

Abstract

In lake Nakaumi, a blackish lake with enclosed waters, the velocity and salinity were measured. The measurements are made for a flow field and distributions of water temperature and salinity using ADCP and other equipments. Through these measurements, the following results are obtained.(1) The currents in enclosed waters depend on not only the change in tide level and water level at the center and inlets of the lake but also the thickness of pycnocline.(2) The pycnocline is subjected to tidal changes over a long time scale.(3) Some internal gravity waves changing thier oscillation period with tides and wind direction were observed.