Interannual and Decadal Variation of Sea level in the East China Sea

摘要

Sea level variation and its dynamic and thermal processes wereinvestigated with the TOPEX/Poseidon (T/P) altimeter data,reconstructed sea level data and tide gauge records on the interannualand decadal scale in the East China Sea (ECS). Stochastic dynamicmethod was used to analyze the characteristics of sea level variation.During 1993 to 2010, the sea level rising rate of the whole ECS was2.5mm/a. The interannual and decadal sea level variations wereremarkable and, focused on 2～4 and 8～10 years. The interannual sealevel variation was influenced by ENSO and the amplitudes mappednon-uniform spatially. The interannual amplitude was less than 5 cm,which steric effects contributed 65%.The correlation between steric sealevel and sea level can reach to 0.93. We found that ocean currents andzonal wind stress exhibited as the main oceanic dynamic factors toinfluence the interannual sea level variation in the ECS, as well as thevertical structure and its changes of temperature and salinity. Bycomparing sea level anomaly with wind stress in the ECS on theinterannual scale, their correlation coefficient was up to -0.65, when thesea level lagged zonal wind stress 3 months. On the decadal scale, windstress and steric effects acted as the important physical processescontributing to the sea level variation.