2010 Volume 16 Pages 513-518
This paper is focused on the endothermic effect of the tidal flat in subtropical estuaries. When tidal flats are dried up in midnight, its surface can be cooled by radiation cooling and it can cool flooded seawater. We conducted heat balance observations at two different estuaries, natural estuary and artificial estuary which loses its tidal flat. Heat sensor was used to measure a budget of heat flux from ground to water body directly. The result shows tidal flat can work heat absorber. The maximum budget of heat flux was about 60W/m2. Another survey shows it can work almost every morning high tide. This flux value means the endothermic effect tidal flat can work is not so much large to change water temperature drastically but it will be larger than that we ignore if estuaries has a widespread tidal flat. From the standpoint of a conservation of Ryukyu-ayu, which inhabit in Amami Is. only, the cooling effect of tidal flat is considerable because it can reduce deadly seawater temperature (21°C) to safety temperature for Ryukyu-ayu larvae (20͠)
