Climates and Climate Controls

Due to the continental dimensions, Brazil possesses a very wide climatic diversification influenced by its geographical configuration, its significant coastal extension, its relief and the dynamics of the masses of air on the territory. This last factor acts directly on the temperatures and the pluviometric indexes in the different areas of the country. The masses of air are according to the Statistical Annual of Brazil. The Equatorial air mass that is divided in Continental Equatorial and Atlantic Equatorial; the Tropical air mass, also divided in Continental Tropical and Atlantic Tropical; and Polar Atlantic air mass. All these air masses provide the climate differentiations in Brazil. The country’s climate varies from very humid and hot climates, coming of the Equatorial air masses, as its a great part of the Amazon; to very strong semi-arid climates, as those native of the hinterlands of the northeastern part of Brazil. The climate of a given area is conditioned by several factors: temperature, rains, atmospheric humidity, winds and atmospheric pressure. They are also conditioned by factors such as altitude, latitude, relief characteristics, vegetation and continentality. There are five major climates in Brazil. Humid equatorial climate caused by the convergence of the trade winds (Amazônia), tropical climate alternately humid and dry(central area & the coast of the middle-north), tropical climate tends to be dry due to the irregularity of the action of the air masses of air (hinterlands of northeastern Brazil), coastal humid climate exposed to the marine tropical masses (narrow strips of the coast - east and northeast), and humid subtropical climate (south). A great variation in temperature occurs in Brazil. The Northern Area and a part of the interior of the Northeast region experience an annual medium temperature above 25 degrees, while the Southern Area of Brazil and a part of the Southeast have an annual medium temperature below 20 degrees. Absolute minimum temperatures, with frequent negative values are observed in the mountainous summits of the southeast and in a large part of the South Area, which is accompanied by frosts and snow. The North region of Brazil embraces a great part of the Amazon Basin, representing the largest extension of hot and humid forest on the planet. The area is cut by Ecuador and is characterized by low altitudes (0-200m). The climate is hot with an annual medium temperature ranging from 24 degrees to 26 degrees. In the mouth of the river Amazonas, the coast of Pará and in the western section of the area, the total annual pluviometric index exceed 3000 mm in general. The northeast region has high thermal temperatures with an annual average between 20 degrees and 28 degrees, maximums of around 40 degrees. The months of winter have minimum temperatures between 12 degrees and 16 degrees. The pluviosity of the area is complex. Its annual totals vary from 2000mm and values lower than 500mm. The annual medium precipitation in the northeast area is lower than 1000mm. In the southeast region of Brazil the latitudinal position where the Tropic of Capricorn is, has very uneven topography which influences the climate. The annual medium temperature ranges from 20 degrees to 24 degrees. The annual precipitation total is in excess of 1500mm. The South region is located below the Tropic of Capricorn, in a temperate zone. The winters are cold and summers are hot. The annual medium temperature ranges from 14 degrees to 22 degrees, and in places with altitude above 1100m, the temperature drops to approximately 10 degrees. The annual medium pluviosity ranges from 1250 to 2000 mm. In the Middle-West region the annual medium temperature is 22 degrees.The characterization of the pluviosity of the region is almost exclusively due to the system of the atmospheric circulation. The annual medium pluviosity varies from 2000 too 3000 mm.