Nontidal sea level changes generated in Hiroshima Bay of the Seto-Inland Sea in Japan are studied over various time scales, from the sub-tidal (2 d to 1 month) to inter-annual scales (〉2 years). The total sea lev...Nontidal sea level changes generated in Hiroshima Bay of the Seto-Inland Sea in Japan are studied over various time scales, from the sub-tidal (2 d to 1 month) to inter-annual scales (〉2 years). The total sea level variation produces a standard deviation (STD) of 12.5 cm. The inter-annual component of the sea level variation in Hiroshima Bay oscillates with a STD of 3.4 cm, forming a long-term trend of 4.9 mm/a. The STD of the sea level variation is 9.8 cm for the seasonal component (8 months to 2 years) and 4.7 cm for the intra-seasonal one (1 month to 8 months). Significant sea level variations with a STD of 4.2 cm also occur in the sub-tidal range. Special attention is paid to the sub-tidal sea level changes. It is found that the upwelling and associated transient sea level changes generated along the north coast of Hiroshima Bay (opened southward) by the strong northerly wind, play a significant role in sub-tidal sea level changes. The transient sea level changes are over 10 cm in most cases when caused by typhoons that pass through the Pacific Ocean offthe Kii Peninsula, located at about 400 km east of Hiroshima Bay. Reasonable sea level changes are evaluated by the balance of pressure forces at the onshore and offshore boundary of the study domain.展开更多
基金The National Basic Research Program of China under contract No.2011CB403503the National Natural Science Foundation of China under contract Nos 41276095,41176021 and 41321004+1 种基金the Project of Global Change and Air-Sea Interaction under contract No.GASI-03-01-01-02the Grant-In-Aid from the Japan Society for the Promotion of Science
文摘Nontidal sea level changes generated in Hiroshima Bay of the Seto-Inland Sea in Japan are studied over various time scales, from the sub-tidal (2 d to 1 month) to inter-annual scales (〉2 years). The total sea level variation produces a standard deviation (STD) of 12.5 cm. The inter-annual component of the sea level variation in Hiroshima Bay oscillates with a STD of 3.4 cm, forming a long-term trend of 4.9 mm/a. The STD of the sea level variation is 9.8 cm for the seasonal component (8 months to 2 years) and 4.7 cm for the intra-seasonal one (1 month to 8 months). Significant sea level variations with a STD of 4.2 cm also occur in the sub-tidal range. Special attention is paid to the sub-tidal sea level changes. It is found that the upwelling and associated transient sea level changes generated along the north coast of Hiroshima Bay (opened southward) by the strong northerly wind, play a significant role in sub-tidal sea level changes. The transient sea level changes are over 10 cm in most cases when caused by typhoons that pass through the Pacific Ocean offthe Kii Peninsula, located at about 400 km east of Hiroshima Bay. Reasonable sea level changes are evaluated by the balance of pressure forces at the onshore and offshore boundary of the study domain.