On the absolute sea level at the Swedish west coast estimated by VLBI, GNSS, and tide gauges

Other conference contribution, 2025

We analyse the existing ten year time series of sea level observations at the Onsala Space Observatory. A time series of ten years is however too short to result in a stable value for a linear trend. Therefore we compare the sea level data acquired at Onsala with those from the nearby tide gauge station Ringhals. The tide gauge at Ringhals started operations in late 1967. Using Ringhals sea level data we estimate a linear trend for the relative sea level
of 0.54 mm/year. Space geodesy observations using Very Long Baseline Interferometry (VLBI) from 1980 to 2020 and Global Navigational Satellite Systems (GNSS) from 1994 to 2020 have resulted in estimates of the land uplift of 2.9 mm/year and 2.7 mm/year, respectively. Combining the relative sea level trend at Ringhals with the land uplift at Onsala result in an estimate of 3.3 mm/year for the linear trend of the absolute sea level for this region. This is in agreement with recent estimates for the linear trend of the global sea level rise during this time period.