BARYSTATIC sea level changes are due to freshwater exchanges with the continents, including ice mass changes from Greenland, Antarctica and continental glaciers, as well as freshwater fluxes from continental areas (i.e. large river basins such as the Amazon or Mississippi).

MANOMETRIC sea level changes are due to several processes, including the atmosphere - ocean circulation, sea level fingerprints or global water cycle. Climate modes, such as the El Nino Southern Oscillation, Arctic Oscillation, North Atlantic Oscillation or Southern Annular Mode, have also been shown to significantly influence manometric sea level changes (e.g. Pfeffer et al., 2022).

The estimation of barystatic and manometric sea level anomalies is extended to the altimetry era (January 1993 - December 2020) using the sea level budget approach. The sea level budget approach takes advantage of the redundant ocean monitoring systems, measuring geocentric sea level changes with satellite radar altimetry, barystatic and manometric sea level changes with satellite gravimetry and steric sea level changes with in-situ temperature and salinity estimates. Any of the three components may be estimated based on the two others. As a consequence, barystatic and manometric sea level changes may be estimated as the difference between altimetry-based sea level changes and in-situ estimates of steric sea level changes.

References:

- Barnoud, A., Pfeffer, J., Cazenave, A., Fraudeau, R., Rousseau, V., and Ablain, M. (2023). Revisiting the global mean ocean mass budget over 2005–2020, Ocean Sci., 19, 321–334, https://doi.org/10.5194/os-19-321-2023

- Pfeffer, J., Cazenave, A. & Barnoud, A. (2022). Analysis of the interannual variability in satellite gravity solutions: detection of climate modes fingerprints in water mass displacements across continents and oceans. Clim Dyn 58, 1065–1084. https://doi.org/10.1007/s00382-021-05953-z