Global Sea Level Observing System

Project Description
The Global Sea Level Observing System (GLOSS) is an international
programme coordinated by the Intergovernmental Oceanographic
Commission (IOC) for the establishment of high quality global and
regional sea level networks for application to climate, oceanographic
and coastal sea level research. The programme became known as GLOSS as
it provides data for deriving the 'Global Level of the Sea Surface'.

The main component of GLOSS is the 'Global Core Network' (GCN) of 287
sea level stations around the world for long term climate change and
oceanographic sea level monitoring.

The Core Network is designed to provide an approximately
evenly-distributed sampling of global coastal sea level
variations. Another component is the GLOSS Long Term Trends (LTT) set
of gauge sites (some, but not all, of which are in the GCN) for
monitoring long term trends and accelerations in global sea
level. These will be priority sites for Global Positioning System
(GPS) receiver installations to monitor vertical land movements, and
their data will contribute to long term climate change studies such as
those of the WMO-UNEP Intergovernmental Panel on Climate Change

The GLOSS altimeter calibration (ALT) set consists mostly of island
stations, and will provide an ongoing facility for mission
intercalibrations. A GLOSS ocean circulation (OC) set, including in
particular gauge pairs at straits and in polar area, complements
altimetric coverage of the open deep ocean within programmes such as

GLOSS can be considered a component of IOC's Global Ocean Observing
System (GOOS), and particularly as a major contributor to its Climate
and Coastal Modules. Information on the links between GLOSS and other
IOC activities can be obtained from IOC's own web pages.

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