Upwelling and its influence on nutrient concentration in the coastal area of the Hanko Peninsula, entrance of the Gulf of Finland

摘要: Abstract Upwelling was found to be a rather common phenomenon in the coastal area of Hanko Peninsula. Intensive hydrographic and current measurements were made during 10 upwelling episodes 1987-88. A clear relationship noted between wind direction, direction change salinity at 35 m depth moderate or strong winds. observed as sudden increase (Δ S ∼ 1) slight surface layer. When thermal stratification prevailed, layer temperature dropped by much °C, nutrient concentrations increased; that PO 4 -P from 1-2 μg -Pl -1 4-8 NH -N 0·5-2 -Nl up 20 . During upwelling, offshore flow compensated onshore lower In study coastline followed east-west axis occurred when directions 190°-280°, impulse least ∼5000 kg s (50 h wind). The minimum required for seemed inversely proportional power 5-10 buoyancy. This means necessary is fairly constant more homogeneous water column energy needed (up 14 000kg ).