GLOSS or the Global Sea Level Observing System is an international programme conducted under the auspices of the "Joint Technical Commission for Oceanography and Marine Meteorology" (JCOMM) of the "World Meteorological Organisation" (WMO) and the Intergovernmental Oceanographic Commission (IOC) of UNESCO.
GLOSS aims at the establishment and coordination of high quality global and regional sea level networks. The data delivered serve climate, oceanographic and coastal sea level research and ocean policy (a.o. long-term data for the follow-up of climate change and sea level rise).
The programme was established in 1985. It evolved from a small group of scientists concerned with the application of tide gauge data for oceanographic research, into a diverse panel of researchers, engineers, station operators, tsunami warning centre managers, and ocean policy makers involved with the full spectrum of information provided by a network of tide gauges. In its 25 years of existence the programme became generally 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 290 sea level stations around the world for long term climate change and oceanographic sea level monitoring (see map). 170 are designated by GLOSS as official stations within GCOS (Global Climate Observing System). Other GLOSS designated networks have focused on Long Term Trends (LTT), monitoring the stability of satellite altimeter data (ALT), and assessing various aspects of ocean circulation (OC).
Approximately 57% of the stations within the GLOSS 'Global Core Network' (GCN) are now providing data in real-time via the Internet or the Global Telecommunication System (GTS). Also the ODINAFRICA project of IODE and the networks under the regional tsunami warning systems in the Indian Ocean, North East Atlantic & Mediterranean, Pacific and the Caribbean deliver real-time data. IOC and the VLIZ data centre developed a web-based global Sea Level Station Monitoring Facility for viewing these real-time data. This tracking tool is particularly useful for quickly identifying malfunctioning stations and allows a quick inspection of the raw data stream from individual stations.
On the GE11, or the 11th IOC GLOSS Group of Experts meeting (13-15 May 2009 in Paris), the status and future of the GLOSS network was evaluated. An updated GLOSS Implementation Plan (latest version from 2007) is in preparation that will set specific strategies for completing the 'Global Core Network' (GCN). As database capabilities increase and data communication becomes more automated, more and more GCN stations will be equipped for reporting in real-time or near real-time.
Read more on the back ground, status and future of GLOSS
Contact & information:
Mark Merrifield, Chair GLOSS Group of Experts
Francisco Hernandez, VLIZ - manager Flanders Marine Data Centre