Sea Level Budgets Should Account for Ocean Bottom Deformation.

Area of Science:

• Geophysics
• Oceanography
• Climate Science

Background:

• The conventional sea level budget (SLB) traditionally accounts for ocean mass and steric changes, with solid-Earth movements (like glacial isostatic adjustment) as corrections.
• Elastic ocean bottom deformation (OBD) due to ocean mass load was previously negligible.
• Recent rapid increases in ocean mass have made OBD a significant factor, comparable to steric contributions.

Purpose of the Study:

• To derive a revised sea level budget equation that incorporates elastic ocean bottom deformation.
• To analyze the theoretical implications of OBD within the SLB framework.
• To assess the impact of OBD on global sea level change calculations.

Main Methods:

• Utilized a mass-volume framework allowing for elastic ocean bottom response to mass load.
• Developed a new SLB equation explicitly including OBD.
• Theoretically analyzed the contribution and implications of OBD.

Main Results:

• Ocean bottom deformation is no longer negligible due to rising ocean mass.
• OBD is likely of similar magnitude to the deep steric sea level contribution.
• The inclusion of OBD is essential for accurate global sea level budgets.

Conclusions:

• The conventional SLB requires revision to include elastic ocean bottom deformation.
• Accurate assessment of global sea level change necessitates accounting for OBD.
• This study provides a theoretical basis for incorporating OBD into sea level research.