Global Sea Level Change Rate, Acceleration and Its Components from 1993 to 2016

Investigating the global sea level budget is essential to quantify the total sea level change (altimetry) and its components, including the steric sea level change and the ocean mass change (gravity), where the latter is mainly attributed to four mass-driven components (Greenland, Antarctica, glaciers and land water storage). In this study, a 24-year global ocean mass change is derived by the joint use of Tongji-LEO2021 and Tongji-Grace2018 monthly gravity field models over 1993-2016, with which the sea level budgets in terms of rate and acceleration are investigated over global oceans within the latitudes 66oN to 66oS together with the IGG-SLR-HYBRID gravity field models, altimetry, steric and four mass-driven components. The statistical results show that the global mean ocean mass change rate accounts for similar to 54% of 2.85 +/- 0.30 mm/year of global mean total sea level change. The accelerations of global mean total sea level change and its components are 0.145 +/- 0.025 mm/year2 (altimetry), 0.003 +/- 0.021 mm/year2 (steric), 0.139 +/- 0.047 mm/year2 (ocean mass from Tongji), and 0.137 +/- 0.010 mm/year2 (the sum of mass-driven components) respectively, indicating that the global sea level budget in terms of acceleration can be closed and nearly no acceleration exists in the global mean steric sea level change for the period 1993-2016.

Automated summary

Investigating the global sea level budget is crucial for quantifying the total sea level change and its components. The statistical results show that the global mean ocean mass change accounts for about 54% of the total sea level change. The accelerations of the sea level change and its components can be explained by the ocean mass, steric and mass-driven components, and there is almost no acceleration in the global mean steric sea level change during 1993-2016.