Ocean Bottom Deformation Due To Present-Day Mass Redistribution and Its Impact on Sea Level Observations

Ocean Bottom Deformation Due To Present-Day Mass Redistribution and Its Impact on Sea Level Observations

Frederikse, T. (TU Delft Physical and Space Geodesy)
Riva, R.E.M. (TU Delft Physical and Space Geodesy)
King, A. Matt (University of Tasmania)

2017-11-17

Present-day mass redistribution increases the total ocean mass and, on average, causes the ocean bottom to subside elastically. Therefore, barystatic sea level rise is larger than the resulting global mean geocentric sea level rise, observed by satellite altimetry and GPS-corrected tide gauges. We use realistic estimates of mass redistribution from ice mass loss and land water storage to quantify the resulting ocean bottom deformation and its effect on global and regional ocean volume change estimates. Over 1993-2014, the resulting globally averaged geocentric sea level change is 8% smaller than the barystatic contribution. Over the altimetry domain, the difference is about 5%, and due to this effect, barystatic sea level rise will be underestimated by more than 0.1 mm/yr over 1993-2014. Regional differences are often larger: up to 1 mm/yr over the Arctic Ocean and 0.4 mm/yr in the South Pacific. Ocean bottom deformation should be considered when regional sea level changes are observed in a geocentric reference frame.

Altimetry
Elastic deformation
GPS
Ice mass loss
Sea level
Tide gauges

http://resolver.tudelft.nl/uuid:9ca96469-6ca5-4df7-ae06-edf4b461e507

https://doi.org/10.1002/2017GL075419

0094-8276

Geophysical Research Letters

Institutional Repository

journal article

© 2017 T. Frederikse, R.E.M. Riva, A. Matt King