Sea level in the Arctic

Most important data source for sea level data is the Permanent Service for Mean Sea Level (PSMSL). The PSMSL global data bank contains data from 1461 stations worldwide of which 95 are located in the Arctic circle and two on Iceland just below the Arctic circle. The figures below shows the locations of PSMSL stations in the Arctic and the number of stations per country. The data can be downloaded free of charge from http://www.psmsl.org/data/. There is no PSMSL data available for Greenland.

PSMSL stations figure 1

Number of PSMSL figure 2
The PSMSL data are reduced to a common datum, namely the Revised Local Reference (RLR), which is defined to be approximately 7000 mm below mean sea level. The data is not corrected for land subsidence. The figure below shows an example of time series of annual sea level relative to this RLR at Reykjavik on Iceland. The see level rise amounts to 2.2 mm/year at this station with a 95% confidence bandwidth between 1.6 and 2.9 mm/year. The green dashes line indicate the 50% bandwidth for future observations.

Annual sea level figure 3
For many applications (including climate change studies) the long term time series are required. The map below shows the locations of sites with at least 40 years of RLR data, which are the most useful records for studies of long term sea level trends. Note that the coverage of this map is much poorer than that of the previous map. The number of stations in the Arctic with this long term temporal coverage amounts to 52. There is no long term data available in Greenland, Canada and the USA.

PSMSL stations 40 years figure 4

Number of PSMSL 40 years figure 5