Contributions of Greenland and Antarctica to Global and Regional Sea Level Change Oceanography

While it is well known that the accelerating melting of the ice sheets of Greenland and Antarctica will increasingly raise global mean sea levels, it is less widely understood how the addition of meltwater from these ice sheets will affect regional patterns of sea level rise. The transfer of water mass from the ice sheets to the ocean will alter Earth’s gravity field and rotation, resulting in local changes in sea levels. On time scales from months to decades, the addition of freshwater at high latitudes will alter the mean ocean circulation through a variety of mechanisms that will also alter regional rates of sea level change. The current ocean observing system, including radar and laser altimeters, satellite gravity missions, and the Argo network of profiling floats, has demonstrated the ability to close the sea level budget since 2005, confirming the contributions of ice sheets to contemporary sea level rise. The planned observing system will be capable of monitoring the regional variability of sea level change, which should help improve future projections.