The long-term variations in water temperature and salinity in Bisan-Seto, the central Seto Inland Sea

摘要

The long-term variations in water temperature and salinity in Bisan Seto were analyzed using the monthly data measured at the fourteen stations from 1966 to 2002 and the daily average water temperature observed by the automatic measurement sensor with the buoy in Yashima Bay from 1975 to 2002. Thirty-six month running means of the water temperature and salinity gradually increased during the whole investigated period. The annual average water temperature and salinity gained 0.81 deg C and 0.79 psu for 37 years, respectively. The water temperature from December to May showed significant increasing trend, while the water temperature in other months did not show significant increasing trend. However, the number of days when daily average water temperature exceed 25 deg C for a year risen since 1995.