Global

Sea level

Sea level recorders

The database of the Permanent Service for Mean Sea Level (PSMSL) contains over 65000 station-years of monthly and annual mean values of sea level from over 2200 tide gauge stations around the world. Currently approximately 1000 of these stations are known to be operational. The distribution of data is far from even over the globe with the longer records primarily located in the Northern Hemisphere, with nearly all of the very longest records (>100 years) located around northern Europe and around the Baltic Sea, except for a few stations in North America, Asia and Australia. The PSMSL receives monthly and annual values of sea level from almost 200 national authorities responsible for sea level monitoring in each country or region. Data from each station are entered directly as received from the authority into the PSMSL raw data file for that station (usually called the 'METRIC' file in PSMSL publications). The monthly and annual means so entered for any one year are necessarily required to be measured to a common datum, although, at this stage, datum continuity between years is not essential. While PSMSL makes every attempt to spot inconsistent or erroneous data, the responsibility for the monthly and annual means entered into the METRIC files in this way is entirely that of the supplying authority. In order to construct time series of sea level measurements at each station, the monthly and annual means have to be reduced to a common datum. This reduction is performed by the PSMSL making use of the tide gauge datum history provided by the supplying authority. To date, approximately two thirds of the stations in the PSMSL database have had their data adjusted in this way, forming the 'REVISED LOCAL REFERENCE' (or 'RLR') data set. For scientific purposes, the RLR data set is normally superior to the METRIC, although the latter, which contains the total PSMSL data holdings, can also be analysed bearing in mind the above datum continuity considerations. The contents of the PSMSL data set are described on its web site (www.psmsl.org), which includes interactive data products for relative sea level trends and mean sea level anomalies. The complete data set or individual stations can be downloaded from the web-site, together with supporting metadata. The PSMSL will be pleased to provide data, information and advice to all organisations and individuals interested in measuring and analyzing sea level changes.

Woodworth, P.L., and Player, R. (2003) The Permanent Service for Mean Sea Level: an update to the 21st century., Journal of Coastal Research, 19(2): 287-295.; Simon J. Holgate, Andrew Matthews, Philip L. Woodworth, Lesley J. Rickards, Mark E. Tamisiea, Elizabeth Bradshaw, Peter R. Foden, Kathleen M. Gordon, Svetlana Jevrejeva, and Jeff Pugh (2013) New Data Systems and Products at the Permanent Service for Mean Sea Level, Journal of Coastal Research: Volume 29, Issue 3: pp. 493 - 504. doi:10.2112/JCOASTRES-D-12-00175.1

Permanent Service for Mean Sea Level
National Oceanography Centre, Joseph Proudman Building
Liverpool
Merseyside
L3 5DA
United Kingdom