沿海水位和大尺度气候状态——降尺度技术在日本列岛的应用

沿海水位和大尺度气候状态——降尺度技术在日本列岛的应用

COAST SEA LEVEL AND THE LARGE-SCALE CLIMATE STATE: A DOWNSCALING ERCISE FOR THE JAPANESE ISLANDS

A major problem envisaged in the course of man-made climate change is sealevel rise. The global aspect of the thermal expansion of seawater is reasonably well simulated by present day climate models; the coastal aspects of sea level rise, comprise the regional response to regional atmospheric forcing and to the large-scale oceanic circulation, is not adequately simulated by a global climate model because of insufficient spacial resolution. A method to infer the coastal aspects of sea level change uses a statistical"downscaling"strategy: a linear statistical modeles built upon a multy-year data set of local sea level data and of large-scale oceanic and/or atmopheric data such as sea-surface temperature or sea- level air-pressure. We apply this idea to the sea level along the Japanese coast. The sea level is related to regional and North Pacific sea-surface temperature and sea-level air pressure. Two relevent processes are identified, One process is the local wind set-up of water due to regional low-frequency wind anomalies; the other is a planetary scale atmosphere-ocean interaction which takes place in the eastern North Pacific.