Sea Level Variability around Japan during the Twentieth Century Simulated by a Regional Ocean Model

Abstract

Sea level variability around Japan from 1906 to 2010 is examined using a regional ocean model, along with observational data and the CMIP5 historical simulations. The regional model reproduces observed interdecadal sea level variability, for example, high sea level around 1950, low sea level in the 1970s, and sea level rise during the most recent three decades, along the Japanese coast. Sensitivity runs reveal that the high sea level around 1950 was induced by the wind stress curl changes over the North Pacific, characterized by a weakening of the Aleutian low. In contrast, the recent sea level rise is primarily caused by heat and freshwater flux forcings. That the wind-induced sea level rise along the Japanese coast around 1950 is as large as the recent sea level rise highlights the importance of natural variability in understanding regional sea level change on interdecadal time scales.