Regional biases in absolute sea-level estimates from tide gauge data due to residual unmodeled vertical land movement

Author
Keywords
Abstract
The only vertical land movement signal routinely corrected for when estimating absolute sea-level change from tide gauge data is that due to glacial isostatic adjustment (GIA). We compare modeled GIA uplift (ICE-5G + VM2) with vertical land movement at \~300 GPS stations located near to a global set of tide gauges, and find regionally coherent differences of commonly \textpm0.5\textendash2 mm/yr. Reference frame differences and signal due to present-day mass trends cannot reconcile these differences. We examine sensitivity to the GIA Earth model by fitting to a subset of the GPS velocities and find substantial regional sensitivity, but no single Earth model is able to reduce the disagreement in all regions. We suggest errors in ice history and neglected lateral Earth structure dominate model-data differences, and urge caution in the use of modeled GIA uplift alone when interpreting regional- and global- scale absolute (geocentric) sea level from tide gauge data.
Year of Publication
2012
Journal
Geophysical Research Letters
Volume
39
Date Published
07/2012
ISSN Number
0094-8276
DOI
10.1029/2012GL052348