Field Observation and Development of Numeric Method for Lower Trophic Production Effect Grasp by Artificial Upwelling Producing Structure

Abstract

To evaluate the effect of lower trophic production of the mound, the field observation was executed and the calculation that used the flow and primary ecosystem model was done for the mound set up in the Nagasaki Prefecture Goto offing. Generation of the downward flow on the mound and the mixture of the water mass in the mound back were caught by the field observation at time zone that the flow acts on the upwelling axis. Moreover, the decrease in the water temperature and the rise of the nitrate were understood on the mound slope, and the run-up of the water mass of low temperature and high nutrient in bottom layer was observed. It was suggested that the effect of primary production apper from the calculation result by the model to a sea area left from the mound at about 4 km or more.