Currently, well over 10 000 manned and automatic surface weather stations, 1 000 upper-air stations, 7 000 ships, 100 moored and 1 000 drifting buoys, hundreds of weather radars and 3 000 specially equipped commercial aircraft measure key parameters of the atmosphere, land and ocean surface every day. Add to these some 30 meteorological and 200 research satellites to get an idea of the size of the global network for meteorological, hydrological and other geophysical observations. Once collected, observations are quality-controlled, based on technical standards defined by the WMO Instruments and Methods of Observation Programme (IMOP), then made freely available to every country in the world through the WMO Information System (WIS).
WMO facilitated the establishment, maintenance and continuing expansion of this global network, the activities of which are coordinated within the Global Observing System (GOS) of the WMO World Weather Watch (WWW). The WMO co-sponsored Global Climate Observing System (GCOS) and Global Ocean Observing System (GOOS) also play a major role in improving the collection of required data for the development of climate forecasts and climate change detection.
The WMO Integrated Global Observing System (WIGOS) acts as its umbrella for these networks, using the WMO Information System (WIS) to connect together all regions for data exchange, management and processing.