Seasonal variability of the sea surface height in the East China Sea along the China coast: A model study

The phase of the sea surface height annual variation in the East China Sea along China’s continental coast is delayed from that in the open ocean area, most probably because of seasonal strong monsoon winds. To elucidate this mechanism, we conducted an idealized model experiment using a rectangular shallow ocean with a sloped seafloor forced by southward blowing winds. We obtain a locally confined high SSH near the western boundary found in the East China Sea. The delay of the phase of the sea surface height (SSH) along the China coast can be interpreted as follows. The SSH of the East China Sea is high over large areas in September and low in March due to the expansion/contraction of seawater, which is attributable to the sea surface heat flux. However, near the continental boundary SSH becomes high in January and low in July under the influence of a monsoon winds. The phase delay along the continental boundary should appear by superposing these two time series with a phase difference near the boundary.