CONSEQUENCES OF NORTH PACIFIC SEA-LEVEL OSCILLATION FOR ESTUARINE WATER QUALITY AROUND THE JAPANESE COAST

摘要

Many short-period climatic variations over the circum-pacific area can be associated with the abnormal behavior of the Aleutian Low. The Aleutian Low plays an important role in generating weather patterns over the contiguous United States (Garriot, 1904; Kelein, 1965). The synoptic aspects of the teleconnection involve the position and strength of the westerlies as well as the longitude and amplitude of the quasi-stationary, a long-wave train generated downstream from the variable Aleutian Low. The dependence of the Aleutian Low in fall on the sea-water temperatures in the Northern Pacific developed during the antecedent summer is considered (Namias, 1976). Namias suggested that the few cases where the indicated relationship apparently failed could be explained in terms of external influences like the blocking of the Bering Sea, or the occasional existence of unusually strong SST gradients which change atmospheric baroclinicity and sometimes influence the Aleutian Low. It transpires that a 500hPa height fluctuation corresponding to the PNA pattern presented by Wallace and Gutzler (1981) causes the SST anomalies represented by the first EOF. Yamada and Sekine (1997) indicated that a southward shift along the Japanese coast of the subarctic gyre in response to the southward shift of the Aleutian Low results in the negative SST anomalies, which can not be attributed to either the sensible / latent heat fluxes or Ekman transport.