Variability of climatic and ice conditions in the Bohai Sea, China

The Bohai Sea is a shallow and seasonally ice-covered sea. The annual maximum ice extent has exhibited a large variability during the past observation years. Ice and mean wintertime air temperature data have been collected in the present work, and a preliminary analysis is made of interannual changes of local mean air temperature and ice conditions. The mean wintertime air temperature has increased by 1.0°C and 1.4°C in the recent 10 (1986–95) and 5 years (1991–95), respectively, compared with the mean value of the past 40 years (1956–95). The latest 5 years have been exceptionally mild in the Bohai Sea, and the ice conditions also show an evident retrogradation. In addition, a preliminary discussion on the long-term fluctuation tendencies of the local mean air temperature and ice conditions is made.