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

Abstract

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 66^oN to 66^oS 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 ∼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.

Keywords:

• Global sea level change
• Gravity field models
• Altimetry
• Steric
• Acceleration

Disclosure Statement

No potential conflict of interest was reported by the author(s).

Data Availability Statement

The merged altimetry gridded global sea level height anomalies are accessed at https://doi.org/10.24381/cds.4c328c78. The two situ steric datasets (EN4 and IK09) are accessed at https://doi.org/10.4121/12764933.v3. The Tongji-LEO2021 and Tongji-Grace2018 models are free to access from the websites of http://icgem.gfz-potsdam.de/series/03_other/Tongji/Tongji-LEO2021 and http://icgem.gfz-potsdam.de/series/03_other/Tongji/Tongji-Grace2018, respectively. Four mass components (i.e. Greenland, Antarctica, glaciers and land water storage) are accessed from https://catalogue.ceda.ac.uk/uuid/17c2ce31784048de93996275ee976fff. Besides, the IMBIE 2018 Antarctic and IMBIE 2019 Greenland datasets can be directly downloaded from the website of http://imbie.org/data-downloads/.

Additional information

Funding

The research is supported by the Natural Science Foundation of China [42061134010, 42192532, 41731069 and 42174099] and the National Key R&D Program of China [2021YFB3900101].