海平面变化主要由海水质量变化和比容海平面变化组成。联合GRACE时变重力场与Jason-1卫星测高数据分别研究了全球平均海平面及其质量分量与比容分量的季节性变化(2002-09—2008-04),联合两种卫星数据所得平均海平面变化在周年振幅和相位上与WOA05海洋模型结果具有一致性。估算出研究时间段内全球平均海平面变化及其两个主要分量的长期性趋势,在超过6.5a的时间尺度上,全球平均海平面以+2.0±0.4mm/a的速率上升,其中海水质量变化分量的贡献为+1.4±0.4mm/a,比容变化分量的贡献为+0.5±0.3mm/a。
Sea level variations are mostly caused by ocean mass variations and steric sea level variations.Seasonal variability of global mean sea level and its two components from September 2002 to April 2008 is investigated respectively from combined GRACE time variable gravity and Jason-1 satellite altimeter data.Mean sea level change from combined satellite observations is quite consistent with WOA05 results at annual amplitudes and phases.The secular trend of global mean sea level change and its two components is estimated,during over 6.5 a time scale,global mean sea level rises at a rate of +2.0±0.4mm/a,the respective contribution of ocean mass sea level and steric sea level is estimated to be +1.4±0.4mm/a and +0.5±0.3mm/a.