The Global Sea Level Observing System (GLOSS) is a programme coordinated by the Intergovernmental Oceanographic Commission (IOC) for the establishment of global and regional sea level networks. The main component of GLOSS is the 'Global Core Network' of 287 stations around the world for long term climate change and oceanographic sea level monitoring.
 

 
GLOSS Status as of October 2001 can be summarised in terms of the latest data received by the PSMSL for each station in the network. An 'operational' station from a PSMSL viewpoint means that recent MSL monthly and annual values have been received at Bidston, have been checked as far as possible, and have been included in the databank. For each of the GLOSS stations we have used the year of the last data entered into the databank, if any, to place the station into one of four categories:

Category 1: 'Operational' stations for which the latest data is 1997 or later;
Category 2: 'Probably operational' stations for which the latest data is within the period 1987-1996;
Category 3: 'Historical' stations for which the latest data is earlier than 1987;
Category 4: For which no PSMSL data exist.

The GLOSS Station Handbook has been constructed in order to provide further information on each of the tide gauges in GLOSS. The GLOSS Station Handbook has been updated during 2001, and these pages form Version 5 of the Handbook. The GLOSS Station Handbook contains information on each gauge in the GLOSS tide gauge network as defined by the 'GLOSS97' description of the network (287 gauges). In the course of construction of the GLOSS Implementation Plan 1997, the GLOSS core network was rationalised by the removal of 21 sites from the previous definition (GLOSS95). Plots of annual mean sea level are available for most sites. In addition, site maps, some better than others, are available from many of these stations.

Links to hourly values of sea level data have been added (August 1999). The links to data held at the WOCE 'Fast-Delivery' Data Assembly Centre and the Joint Archive for Sea Level Data (JASL) both operated by the University of Hawaii Sea Level Centre (UHSLC), and the WOCE 'Delayed-mode' Data Assembly Centre, operated by BODC are included in the table below. Other sea level data held by these sites can be found by visting their Web pages. The Handbook also includes references to individual countries and organisations who have made their sea level data (hourly values) available on the Web or have provided information about their tide gauge networks and how to obtain the data. The latest version of the handbook is to be found on BODC's website.