The GCOS addresses the total climate system including physical, chemical and biological properties, and atmospheric, oceanic, terrestrial hydrologic, and cryospheric components. The GCOS is sponsored by the World Meteorological Organization (WMO),the Intergovernmental Oceanographic Commission (IOC) of the United Nations Educational, Scientific and Cultural Organization, the United Nations Environment Programme, and the International Council for Science. The general principle is that a station should provide measurements that are, and remain, representative of the surrounding area, the size of which depends on the meteorological application.