Geodetic Journey

Geodesy is of fundamental importance in observing climate change. Tide gages measure changes in the sea level, and when combined with GNSS measurements at the site, the change in absolute sea level may be determined. Changes in the sea level are generally due to the effect of thermal expansion of the water or redistribution of water and melting ice (water cycle).
 

Changes in the large ice caps of Antarctica, Greenland may be determined from satellite altimetry. For these ice sheets and large regions like Tibet/Himalay with a large number of glaciers these changes may also be observed from satellites measuring the gravity field. On a local scale changes in individual glaciers may be observed from GNSS (land subsidence/uplift) and from superconducting gravimeters.

To determine and monitor the ocean circulation and transport and possible changes in these due to climate change, geodesy needs to provide a high precision geoid, and this is one of the primary objectives for geodesy at the moment. When applied to the Arctic this may also contribute in determining the sea ice thickness, and by doing so, provide oceanographers and climate researchers with valuable data in their research.