We have had another paper published, this time in Geophysical Research Letters, which argues that “Sea level budgets should account for ocean bottom deformation“.
In the paper, we first derive the sea level budget equation from fundamental principles and then update it to include ocean bottom deformation as a separate process.
The conventional sea level budget equation – which underpins the ‘balance-sheet’ approach to the sea level budget that identifies and accounts for all the factors that contribute to sea level rise – does not include elastic ocean bottom deformation, implicitly assuming it is negligible. However recent increases in ocean mass, largely from melting ice sheets and glaciers, mean that this assumption is increasingly invalid.
Our assessment suggests that current-day global‐mean ocean bottom deformation is of a similar magnitude to the deep steric contribution to sea level change, and should consequently be included in sea level budget studies.
Figure 1. Our calculated OBD trend between January 2005 and December 2015.
A plain language summary of the work is available here. The paper has also been featured in Newseek and New Scientist.
Full paper: Vishwakarma, B. D., Royston, S., Riva, R. E. M., Westaway, R. M., & Bamber, J. L. (2020). Sea level budgets should account for ocean bottom deformation. Geophysical Research Letters 47, e2019GL086492 (DOI:10.1029/2019GL086492 
).
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