[A-OS14] 沿岸域における混合，渦，内部波に関わる諸現象

[AOS14-03] 東シナ海陸棚縁辺部における黒潮フロント渦と栄養塩・植物プランクトン動態

*吉江 直樹¹、加部 晏諒¹、大城 一輝¹、堤 英輔²、武田 重信³、石坂 丞二⁴、郭 新宇¹ (1.愛媛大学沿岸環境科学研究センター、2.九州大学応用力学研究所、3.長崎大学水産学部、4.名古屋大学宇宙地球環境研究所)

キーワード：フロント渦、栄養塩、植物プランクトン、東シナ海

The lower-trophic level ecosystem in the continental slope region of the East China Sea (ECS) during summer generally shows typical subtropical features, i.e., small size pico-phytoplankton such as cyanobacteria dominates in the euphotic layer under the oligotrophic condition due to the stable stratification. It is also known that such stable physical and chemical conditions are often disturbed by the Kuroshio frontal eddy. In this study, we investigated the phytoplankton dynamics associated with the passing of Kuroshio frontal eddies. We conducted comprehensive observations with the high horizontal resolution (7km) around the continental slope region in the ECS in the late-July, 2018. We observed drastic changes in the depth of subsurface chlorophyll maximum (SCM) and nitrate concentrations around the SCM, and micro-phytoplankton such as diatom mainly changed around SCM. We found cyclonic frontal eddies with 15-35 km diameter around the 40-80 m depth near the drastic change of the SCM. These changes were caused by the horizontal advection of nutrient-rich shelf water associated with the passing of the cyclonic frontal eddies.