Spatial sea-level reconstruction in the Baltic Sea and in the Pacific Ocean from tide gauges observations

Marco Olivieri Marco Olivieri,Giorgio Spada Giorgio Spada

doi:10.4401/ag-6966

Abstract

<p>Exploiting the Delaunay interpolation, we present a newly implemented 2-D sea-level reconstruction from coastal sea-level observations to open seas, with the aim of characterizing the spatial variability of the rate of sea-level change. To test the strengths and weaknesses of this method and to determine its usefulness in sea-level interpolation, we consider the case studies of the Baltic Sea and of the Pacific Ocean. In the Baltic Sea, a small basin well sampled by tide gauges, our reconstructions are successfully compared with absolute sea-level observations from altimetry during 1993-2011. The regional variability of absolute sea level observed across the Pacific Ocean, however, cannot be reproduced. We interpret this result as the effect of the uneven and sparse tide gauge data set and of the composite vertical land movements in and around the region. Useful considerations arise that can serve as a basis for developing sophisticated approaches.</p>

Highlights

Sea-level variations are a mark of climate change at different spatiotemporal scales
Our main focus will be on the Baltic Sea, since this small basin is well sampled by TGs
Due to the large rates of crustal uplift associated with GIA, in this region a large discrepancy is expected to exist between the relative sea level observed at TGs and the absolute sea level revealed by altimetry

Summary

Introduction

Sea-level variations are a mark of climate change at different spatiotemporal scales. Differently from Choblet et al [2014], we do not impose an a priori tessellation of the reconstructed domain but we use the available TGs as nodes for a standard Delaunay triangulation [Delaunay 1934] at which the value of the rate of sea-level change is observed.

Results

Conclusion