Sea Level Change and Variability Analysis

Sea level change and variability analysis examines the temporal and spatial evolution of ocean surface height as influenced by physical processes within the climate system and the solid Earth. Absolute changes in sea level arise from ocean mass change, chiefly due to ice sheet and glacier melt and variations in terrestrial water storage, and from steric effects driven by temperature and salinity fluctuations. Relative sea level further incorporates vertical land motion, whether from tectonics, glacial isostatic adjustment or human activities such as groundwater extraction. Observational records from satellite altimetry, gravity missions and coastal tide gauges provide complementary perspectives. Recent advances have refined corrections for atmospheric loading, improved reconstructions of vertical land motion and addressed systematic discrepancies among data sets. Such studies underpin projections of regional sea level rise, inform detection of acceleration, and guide coastal adaptation strategies under scenarios of continued climate warming.

Research from Nature Portfolio

Reconstruction of the global and regional ocean mass budget since 2003 has revealed close alignment between satellite gravity estimates and density-corrected ocean volume observations after implementing updated wet troposphere and halosteric corrections. The analysis attributes nearly all of the two-decade net ocean mass increase to ice mass loss and water management changes, while quantifying interannual variability from terrestrial water storage. A probabilistic reconstruction of vertical land motion from 1995 to 2020 shows that nonlinear tectonic and loading effects can substantially alter projections of relative sea level, contributing up to half a metre locally by 2150 and increasing regional uncertainty by nearly one metre. The findings underscore the necessity of integrating nonlinear land movement in long-term sea level projections.

Sea Level Change and Variability Analysis publication trend

The graph below shows the total number of articles in sea level change and variability analysis across all publications each year (not limited to Nature Index journals).

Technical terms

Global Mean Sea Level (GMSL): The average height of the ocean surface relative to the Earth’s centre of mass, primarily derived from satellite altimetry.

Relative Sea Level (RSL): Local sea level measurement relative to the land at a specific site, combining changes in GMSL with vertical land motion.

Steric Sea Level: Sea level variation resulting from changes in water density due to temperature (thermosteric) and salinity (halosteric) effects.

Vertical Land Motion (VLM): Upward or downward movement of the Earth’s crust that alters relative sea level readings at coastal sites.

Ocean Mass Budget: An accounting framework for the sources and sinks of water mass in the ocean, including ice melt and terrestrial storage changes.

Satellite Altimetry: A remote-sensing technique that measures sea surface height by timing radar pulses emitted from orbiting instruments.

References

1. Global and regional ocean mass budget closure since 2003. Nature Communications (2024).
2. Regional variations in relative sea-level changes influenced by nonlinear vertical land motion. Nature Geoscience (2024).
3. The ULR-repro3 GPS data reanalysis and its estimates of vertical land motion at tide gauges for sea level science. Earth System Science Data (2023).
4. Vertical land motion monitored with satellite radar altimetry and tide gauge along the Texas coastline, USA, between 1993 and 2020. International Journal of Applied Earth Observation and Geoinformation (2023).
5. Climate-change–driven accelerated sea-level rise detected in the altimeter era. Proceedings of the National Academy of Sciences of the United States of America (2018).