Field Survey on a Relationship Between Development and Decay Processes of Salinity Stratification Due to Floods and Turbulent Structures in the Northern Ariake Sea

Abstract

フェロー会員 工博 九州大学大学院教授 工学研究院環境社会部門（〒819-0395 福岡市西区元岡744）2 学生会員 九州大学大学院 工学府海洋システム工学専攻（同上） 3 正会員 工博 九州大学助教 高等研究院（同上） 4 学生会員 工修 長崎大学大学院 工学研究科生産システム工学専攻（〒852-8521 長崎市文教町1-14） 正会員 工博 長崎大学大学院教授 工学研究科システム科学部門（同上）To understand difference of density stratification due to freshwater transport from rivers through flood events and tidal range (spring tide or neap tide), four time 25 hours continuous field measurement on tidal current, CTD, turbulence micro-structure, and suspended solid (SS) particle size property were conducted at a point in the northern Ariake Sea in summer and winter in 2014. From the results, the followings were clarified: 1) sub-tidal development and decay process of saline-freshwater stratification during flood season was clearly measured; 2) Turbulent energy dissipation rate was correlated to mean flow velocity in spring tide in winter only, but not in neap tide and in stratified spring tide; and 3) Tempo-vertical profiles of eddy viscosity and dissolved oxygen were related to condition of stratification.