Ocean State Report 2016: mean sea level monitoring

Temporal evolution of globally averaged daily MSL without annual and semi-annual signals (blue), 9-month low-pass filtered MSL (red) and annual mean thermosteric sea level (0–700 m) (green, uncertainty estimation method after von Schuckmann et al. 2009) anomalies relative to the 1993–2014 mean.

Global mean sea level (MSL) rise is one of the most adverse consequences of climate change.

The precise monitoring of sea level is crucial to comprehend the socio-economic consequences associated with its contemporary rapid rise and to understand rise due to climate change. Accurate monitoring of this variable is also required to understand the sea level variability and changes over a wide range of temporal and spatial scales, from seasonal to decadal periods and from regional to global scales. Since 1993, variations in sea level have been routinely measured by high-precision satellite altimetry.
The trend of global MSL during the 1993–2015 period amounts to 3.3 mm/yr±0.5 mm/yr.
The present-day global MSL rise primarily reflects ocean warming (“thermosteric” sea level, through thermal expansion of sea water) for about 1.0 mm/yr for the first 700 m of the ocean (about 1/3 of the current rise), and ocean mass increase in response to land ice melt.

See Ocean state report 2016 for details and more information.