Brazilian meteorologists were confronted with many special missions and tough problems as the profession coalesced in the early twentieth century. For one, there was a certain expectation from policy makers and other public figures that meteorologists should be able to explain the recurring and devastating droughts assailing the Northeastern region of Brazil. Secondly, meteorologists were also expected to be of assistance in resolving Brazil's "spatial problem." As the fifth largest landmass in the world, but with its population densely hugging the coast, Brazilian policy makers have always considered the country's vast and sparse frontiers to be both a problem and a blessing. It was so vast the federal government could hardly control it, but if it did, it held the promise of rich natural resources and abundant land.

Yet unlike the developed nations that in the twentieth century already had territorialized their frontiers through railways, Brazil lacked any substantial transportation networks into the interior. As the state turned to the west and sought to grasp a firmer control of its territories, it saw aviation as the key to maintain this territorial domain. But to maintain safe regular aviation service into the far flung frontiers, Brazilian meteorologists had to understand the atmosphere above its tropical hinterlands.

Early twentieth century Brazilian meteorologists were divided among a variety of organizations, some more interested in pure scientific research, and others in more pragmatic weather forecasting over the Brazilian territory, for which proponents of extending air routes clamored. How did this relationship between aviation technology and the meteorology affect the development of the atmospheric sciences in Brazil? How did the demands of a government looking to the Brazilian west, and the needs of airlines interested in the profitable air routes down the populated coast affect the professionalization and growth of Brazilian meteorology? My paper will chronicle these early developments in the formation of the Brazilian Meteorological Service, focusing on how it affected, and was affected by, developments in Brazilian aviation.