Author(s): T. Kurokawa; S. Fukuoka
Linked Author(s): Takeshi Kurokawa
Keywords: Brackish lake Lake Nakaumi atmospheric pressure; Pycnocline wind-driven current dissolved oxygen
Abstract: Lake Nakaumi that is a brackish lake has strong pycnocline, so that dissolved oxygen in the bottom layer is often depleted. Brackish lake is subject to composite meteorological, oceanographic and hydrological influences that give them complex flows. The meteorological characteristics exerting influences on Lake Nakaumi, together with the flows in the lake caused by meteorological change and its water quality distribution, were examined in order to clarify the relationships between meteorological change, flows and water quality environment in the lake. The following results were obtained; (1) The meteorological changes giving rise to the external forces (wind, and water level difference between the waters) generating the flows involve combinations of atmospheric pressures and wind direction at times when strong winds occur. (2) Seawater inflow and wind-driven current by approach of the low atmospheric pressure carry dissolved oxygen into bottom layer of Yonago Bay. (3) During the period of mild weather, internal wave in the back of Yonago Bay is different from that generated in the other area of the lake. The anoxic water mass moves from the back of the bay towards the center.
Year: 2003