Total sea level variations(SLVs) are caused by two major components:steric variations due to thermal expansion of seawater,and mass-induced variations due to mass exchange between ocean and land.In this study,the g...Total sea level variations(SLVs) are caused by two major components:steric variations due to thermal expansion of seawater,and mass-induced variations due to mass exchange between ocean and land.In this study,the global SLV and its steric and mass components were estimated by satellite altimetry,Argo float data and the Gravity Recovery and Climate Experiment(GRACE) data over 2005-2014.Space gravimetry observations from GRACE suggested that two-thirds of the global mean sea level rise rate observed by altimetry(i.e.,3.1 ± 0.3 mm/a from 2005 to 2014) could be explained by an increase in ocean mass.Furthermore,the global mean sea level was observed to drop significantly during the2010/2011 La Nina event,which may be attributed to the decline of ocean mass and steric SLV.Since early 2011,the global mean sea level began to rise rapidly,which was attributed to an increase in ocean mass.The findings in this study suggested that the global mean sea-level budget was closed from 2005 to 2014 based on altimetry,GRACE,and Argo data.展开更多
基金supported by the National Key Basic Research Program of China(973 program,2012CB957703 and2013CB733305)the National Natural Science Foundation of China(41431070,41174066 and 41321063)
文摘Total sea level variations(SLVs) are caused by two major components:steric variations due to thermal expansion of seawater,and mass-induced variations due to mass exchange between ocean and land.In this study,the global SLV and its steric and mass components were estimated by satellite altimetry,Argo float data and the Gravity Recovery and Climate Experiment(GRACE) data over 2005-2014.Space gravimetry observations from GRACE suggested that two-thirds of the global mean sea level rise rate observed by altimetry(i.e.,3.1 ± 0.3 mm/a from 2005 to 2014) could be explained by an increase in ocean mass.Furthermore,the global mean sea level was observed to drop significantly during the2010/2011 La Nina event,which may be attributed to the decline of ocean mass and steric SLV.Since early 2011,the global mean sea level began to rise rapidly,which was attributed to an increase in ocean mass.The findings in this study suggested that the global mean sea-level budget was closed from 2005 to 2014 based on altimetry,GRACE,and Argo data.