Sea level is the time-varying height of the ocean surface relative to the geoid. Sea level is one of the most sensitive and impactful indicators of global climate change. Monitoring changes in the global mean sea level enables to distinguish between ocean mass variations due to melting of glaciers and ice sheets, and ocean volume changes due to thermal expansion. Time series of global sea level observations provided by geodesy are essential for monitoring the global ocean areas, modelling geostrophic currents and seasonal variability, and projecting long-term sea level rise. Relative sea level observations are important for detecting changes in temperature, salinity, and circulation at local levels. These observations combined with vertical land motion data also provided by geodesy are essential for estimating the apparent sea level change in coastal areas, which in turn is needed to inform policy makers in the management of coastal risks. The following geodetic products are key to realising, monitoring and applying this Essential Geodetic Variable:
IAG as part of the IUGG
IAG Related Organisations
IAG collaborates closely with numerous organizations within geodesy and beyond. See the list for details.
This website is provided by the IAG Secretariat and the GGOS Coordinating Office, which are hosted by the BEV – Federal Office of Metrology and Surveying (Bundesamt für Eich- und Vermessungswesen) in Vienna, Austria.