1961～2015年苏北沿岸海面变化特征及其对全球气候的响应

Sea-level change on the northern Jiangsu coast during 1961～2015 and its links with global climate

伴随工业革命以来的全球增温,海洋热力膨胀以及冰川融化引起了全球海面持续上升.叠加在这一长期趋势上的局地地壳运动造成了海面变化的区域差异.通过分析连云港和吕四验潮站的潮位记录,探讨苏北沿岸1961-2015年的海面变化特征.结果表明,经历了一个短暂的加速下降期后,该区海面自1970年代以来表现为连续的上升趋势,具有全球一致性.但在个别时段,海面上升的速率明显高于全球平均值,反映了局地地面沉降的主导作用.

The global warming since the industrialization has led to remarkable thermal expansion of the upper ocean and melting of the polar and mountain glaciers,which in turn resulted in a progressive rise of global sea level with variable rates.Superimposed on this long-term trend,localized vertical land motion may have amplified the sea-level rise and resulted in remarkable regional variability.In this study,continuous tide gauge records from the Lianyungang and Lüsi station are analyzed using state-of-the-art methods such as multi-taper spectral analysis,locally weighted scatterplot smoothing,and stepwise regression to identify the seasonal cyclicity,long-term trend,and rate and acceleration of sea-level rise since 1961.The results show that local sea level rose steadily since the 1970 sfollowing a decade of accelerated fall,which is consistent with global sea-level rise.However,local sea level rises at a rate significantly higher than the global mean value during some period,due primarily to the localized land subsidence.Therefore,continuously monitoring the vertical land motion in this area is of great importance for improving the projection of future sea-level rise.