Drivers for seasonal variability in sea level around the China seas

Globally variable ocean and atmospheric dynamics lead to spatially complex seasonal cycles in sea level. The China Seas, that is the Bohai, Yellow, East South seas, a region with strong amplitudes, straddles transition between tropical temperature zones, monsoonal westerlies, shelf deep zones. Here we investigate drivers for variability level from tide gauge records, satellite altimetry along output NEMO (Nucleus European Modeling of Ocean) model including surface height bottom pressure meteorological data Seas. cycle accounts 37% - 94% monthly 81 ranging 18 59 cm. We divided into four types: 1) an asymmetric sinusoid; 2) clearly defined peak on flat background; 3) relatively signal; 4) symmetric co-sinusoid. Type 1 found northern Taiwan, Korea, Japan Philippines where Inverse Barometer (IB) effects dominates seasonality steric contribution. monsoon associated barotropic response freshwater exchange play important roles type 2, (eastern southern Chinese coasts), 3 (East Malaysia) 4 (Vietnam Gulf Thailand). IB corrected amplitudes are larger continental areas than ocean, maximum Thailand, underestimates amplitude coast by nearly 50%.