Abstract's details

Secular and seasonal reconstructing of global and regional sea level change

Carsten Ludwigsen (DTU Space, Denmark)


Andersen Ole (DTU Space, Denmark)

Event: 2022 Ocean Surface Topography Science Team Meeting

Session: Science I: Climate data records for understanding the causes of global and regional sea level variability and change

Presentation type: Type Oral

Here we present a global sea level reconstruction from 1992 to 2021. Each mass contribution (Greenland, Antarctica, Glaciers, Terrestrial Water Storage, GIA) to both relative (S) and absolute sea level (N) and vertical land movement (U = N - S) and the halo- and thermosteric contribution is defined monthly in an equal-area grid (r ~ 45km). This allows for reconstructing both secular and seasonal sea level changes at any location of the globe.

Each contributions is defined from the mean of 1000 ensemble calculations. The standard deviation of the ensembles provides the uncertainty.

Globally, the reconstruction fits the global mean sea level (GMSL) observations from altimetry from 1992-2016, with only small monthly misfits (varies between +/- 0.5 cm), while the timeseries GRACE/GRACE-FO agrees with the monthly variations of the sum of the mass contributions (+/- 0.2 cm misfit). After 2016 the trends of Altimetry and the reconstruction begin to deviate with a total disclosure of up to 1.5 cm in 2021, while the mass contribution still aligns with GRACE/FO. Around 2016 we observe that the halosteric sea level contribution is declining, after been around zero from 1992-2015. This indicates a fault in the halosteric calculations possibly related to instrumental problems of the ARGO profiles that results in faulty salinity measurements. Removing the halosteric component removes around 50% of the misclosure, leaving the remaining disclosure unexplained.

Comparisons with altimetry and tide gauges at different locations will be shown at both seasonal and long-term time-scales.
Secular and seasonal reconstructing of global and regional sea level change

Oral presentation show times:

Room Start Date End Date
Sala Grande Mon, Oct 31 2022,17:15 Mon, Oct 31 2022,17:30
Carsten Ludwigsen
DTU Space