Sea level variation and its dynamic and thermal processes were investigated with the TOPEX/Poseidon (T/P) altimeter data, reconstructed sea level data and tide gauge records on the interannual and decadal scale in the East China Sea. Stochastic dynamic method was used to analyze the characteristics of sea level variation. During 1993 to 2010, the sea level rising rate of the whole ECS was 2.5mm/a. The interannual and decadal sea level variations were remarkable and, focused on 2~4 and 8~10 years. The interannual sea level variation was influenced by ENSO and the amplitudes mapped non-uniform spatially. The interannual amplitude was less than 5 cm, which steric effects contributed 65%.The correlation between steric sea level and sea level can reach to 0.93. We found that ocean currents and zonal wind stress exhibited as the main oceanic dynamic factors to influence the interannual sea level variation in the ECS, as well as the vertical structure and its changes of temperature and salinity. By comparing sea level anomaly with wind stress in the ECS on the interannual scale, their correlation coefficient was up to -0.65, when the sea level lagged zonal wind stress 3 months. On the decadal scale, wind stress and steric effects acted as the important physical processes contributing to the sea level variation.
The sea level is a very sensitive indicator of climate change, it has been a topic of keen interest among international governments and scientists nowadays. In the past decades, a series of studies have devoted to estimate the sea level rising rate, reported in the IPCC Fourth Assessment Report. Sea level trend is highly non-uniform spatially, for example the rates in some regions, such as the Pacific warm pool, are up to several times of the global mean, while in other regions sea level is falling.
