On the combination of altimetry and tide gauge observations in the Norwegian coastal zone

Abstract

We have, using altimetry observations, investigated the nature and magnitude of variations in the local mean dynamic topography (MDT) along the Norwegian coast. Following our findings, we argue that the MDT is well approximated by the nearest observation and demonstrate how the results can be improved using variogram based kriging. Cross validation at tide gauges along the coast confirms the applicability of the approach and, therefore, gives us some confidence in its ability to weigh altimetry and tide gauge observations appropriately. Accordingly, altimetry is a potentially very important source of information on mean sea level outside the Norwegian baseline.

Keywords

• altimetry
• geodesy
• interpolation
• kriging
• mean dynamic topography
• sentinel-3
• tide gauges
• uncertainty