The Development of Internal Wave and Its Influence on Water Quality and Primary Production Induced by the Intrusion of "Kyucho" in the Inner Part of SurugaBay

Abstract

Continuous observation of current, temperature and water quality in the inner part of Suruga Bay were carried out since August 2007. In middle April 2008, sudden temperature rise about 4 degree was observed. The temperature rise was influenced by the intrusion of the Kuroshio warm water, so-called "Kyucho", which persisted for a few days. Kyucho occurred tree times and generated stratification in the upper layer of the inner part of the bay. After intrusion of Kuroshio warm water, internal waves with the period of half a day, caused by stratification were observed. Internal wavers generated strong currents, having the maximum velocity of about 30cm/s, which induced nutrients uptake from the lower layer.