16 Jan 2013
The web pages illustrating the trends in the tide gauge data set, as well as yearly variation of sea level with respect to an average (the sea level anomalies), were updated with the 09 Jan 2013 release of the data set. The release date is displayed on both pages in line with our referencing recommendation. In response to user feedback, we have also change the associated table of trends to include the entire time span of the tide gauge time series. One should take suitable note of the user warnings associated with these trend estimates, however.
Each year, the Permanent Service for Mean Sea Level (PSMSL) starts anew to gather as much data as possible from the previous year to update the tide gauge time series. For example, during 2012 we tried to update all time series from active stations with the 2011 data. Other changes also occur to the data set over the course of a year. In some cases, the yearly effort includes the addition of new time series. Occasionally, data suppliers provide a replacement time series for an existing record. Thus, changes to the data set frequently reflect more than an addition of 12 monthly means. This update marks an internal milestone as we start a new year and provides the best opportunity to update our products.