WIND RESPONSE OF HYPOXIC WATER MASS IN ISAHAYA BAY

Abstract

  The wind response of hypoxic water mass in Isahaya Bay was investigated by using the data of wind and water quality measured in July and August of 2008 by the Kyushu Regional Agricultural Administration Office. In Isahaya Bay, the south-southwest wind and north-northeast wind were prevailing in summer season. When the southerly wind is blowing for a long period, the hypoxic water mass formed between the mouth and the central part of Isahaya Bay was transported shorewards and was upwelled at the inner area of the bay. On the other hand, the northerly wind improved the water environments in the inner area of the bay by transporting onshorewards the surface layer water with high DO-concentration and by pushing away offshorewards the hypoxic water mass. The front of the hypoxic water mass moves at the order of several hundreds meters per hour along the on-offshore direction.