International Meteorological Organization
The International Meteorological Organization (IMO; 1873–1951) was the first organization formed with the purpose of exchanging weather information among the countries of the world. It came into existence from the realization that weather systems move across country boundaries; and that knowledge of pressure, temperature, precipitations, etc. upstream and downstream is needed for weather forecasting. It was superseded by the World Meteorological Organization. History. The Renaissance brought significant development of instruments to measure atmospheric phenomena and scales to compare them. Subsequent developments in atmospheric science in the 18th Century confirmed the need for widespread measurement and uniform transnational  measurement scales. In the early 19th Century countries began to share meteorological data, and on this basis a conference was held in Cambridge in 1845 with representation by the leading British and European meteorologists, including: Matthew Fontaine Maury, of the US Navy, initiated the convening of the first true International Meteorological conference from late August through early September 1853. The Conference opened its proceedings at Brussels, Belgium, on the 23d August 1853, in the residence of M. Piercot, the Minister of the Interior. The Governments represented at the first International Conference, and the names of the officers who attended were  : C. H. D. Buys Ballot's 1872 paper "Suggestions on a Uniform System of Meteorological Observations" pushed for the creation of an international body, and a second International Meteorological Congress was held in Vienna, Austria-Hungary, in September 1873 which agreed to begin preparations for an "International Meteorological Organization" ("IMO"). There they decided that membership would be the directors of national meteorological services. A Permanent Meteorological Committee was established with Buys Ballot, director of the Dutch meteorological service, becoming the first president. A second congress in Rome 1879 decided on the IMO establishment and elected an International Meteorological Committee to  prepare for the next Conference of Directors. There was however no separate funding. Also the directors agreed on a collaborative research effort with the International Polar Year 1882-1883. The first International Meteorological Tables were published in 1889. The 1891 Conference of Directors of Meteorological Services convened in Munich. The organization was further refined by electing an Executive Bureau and deciding upon the first permanent topic commission, the Commission for Terrestrial Magnetism. The 1896 Conference of Directors in Paris established more commissions: the Commission for Radiation and Insolation, and the Commission for Aeronautics. At the same year IMO published the  first International Cloud Atlas. In 1905 the Conference of Directors convened in Innsbruck. Léon Teisserenc de Bort proposed a telegraph-based worldwide weather station network, the "Réseau Mondial". Simplifying Teisserenc de Bort's vision, the IMO decided that the network should collect, calculate, and distribute monthly and annual averages for pressure, temperature, and precipitation from a well-distributed sample of land based on meteorological stations, in effect a global climatological database. The distribution standard was two stations within each ten-degree latitude/longitude quadrangle. Ultimately, the network comprises about 500 land stations between 80°N and 61°S.  The first annual data set, for 1911, appeared in 1917. Between the two world wars there were four further Conferences of Directors, 1919 in Paris, 1923 in Utrecht, 1929 in Copenhagen and 1935 in Warsaw. The IMO did not acquire a permanent secretariat until 1926, and the latter's annual budget never exceeded US$20,000. In September 1929 the Copenhagen Conference of Directors set up a technical Commission For Climatology, which held a meeting at Innsbruck discussing issues such as the relationship between dynamic meteorology and climatology. At its 1934 Wiesbaden meeting the Commission designated the thirty-year period from  1901 to 1930 as the reference time frame for climatological standard normals. the baseline for measuring climate fluctuations. The 1946 Conference of Directors acknowledged the need for an organisation supported by governments. Preparations continued with conferences in 1947 in Washington DC and 1961 in Paris. In 1951 the World Meteorological Organization became a specialized agency of the United Nations in direct succession of the IMO. The members of the WMO are representatives of their respective countries, not their weather services.