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South America


Mystical Mix Of Weather


       South America can be divided into four distinct climatic zones tropical, temperate, dry, and cold based on the general characteristics that typify the continent. Variations of relief particularly elevation and such factors as rain shadows, bodies of water, and wind patterns, however, create a multitude of microclimates.

Tropical climates:

        Most of the Orinoco Basin and virtually all of the Amazon Basin, as well as the lower parts of the Guiana Highlands and the eastern foothills of much of the Andes, have a climate characterized by continuous high temperatures and heavy rainfall. There is little seasonal variation in temperatures because this zone lies along the equator. There is some variation between daytime and nighttime temperatures, though the nightly low temperature seldom drops below 18 C. Average temperatures are usually in the upper  20s C with only a few degrees difference between the warmest and coldest months. Throughout this region rainfall totals are high with some places averaging more than 254 centimetres of rain per year. Humidity is high all year. Savanna climates with a pronounced dry season lie at the edges of some of the tropical zones. Much of the northern half of the Brazilian Highlands falls into this category, as do parts of Venezuela and Ecuador. In general these areas have greater extremes of temperature and lower overall rainfall totals.

Temperate climates:

       South of the Tropic of Capricorn, the climates are cooler than elsewhere in South America, with a pronounced winter season. The southern part of Brazil, most of Paraguay, all of Uruguay, and northeastern Argentina share a humid subtropical climate, with rainfall common throughout the year and generally warm summers and cool winters. Extremes of temperature are greatest away from the moderating effects of the ocean that is, in the Gran Chaco region of Paraguay and the western part of the Parana plateau in Brazil. Central Chile has a climate similar to that of the Mediterranean area, with hot summers and cool, wet winters. Southern Chile has a marine west coast climate cool temperatures year-round with rainfall throughout the year. Although proximity to the ocean tends to moderate temperature extremes, some areas in southern Chile have very cold temperatures and extremely high rainfall.

Dry climates:

       Four areas in South America have climates characterized by a lack of rainfall. The two main desert areas are along the west coast of the continent and in Argentina. Much smaller dry areas are found in northeastern Brazil and along the coast of Venezuela. The entire coastal area of Peru and the northern part of Chile is one of the driest regions on the surface of the Earth. Cold waters off the coast and the proximity of the high Andes, as well as wind patterns out of the South Pacific high pressure system, contribute to the virtual lack of rainfall in this region. This is a cool, humid desert, however, resulting in pleasant living conditions for those not bothered by the lack of rainfall.

        Argentina is crossed from northwest to southeast by an arid belt. The northern part of this region, around San Miguel de Tucuman and Mendoza, has the greatest range of temperatures in the entire continent, with hot summers and cool winters. Farther south in Patagonia the influence of the ocean results in lower overall temperatures without the extremes that are common inland. These dry areas in Argentina are all the result of being in the rain shadow of the Andes.

Cold climates:

        Average annual temperatures of less than 10 C are found in the southernmost parts of Argentina and Chile and at high elevations throughout the Andes. A damp, cold climate characterizes the Tierra del Fuego region. Constant high winds make the southern tip of the continent an unattractive place for human settlement.

       Vertical climate zones have resulted in the use of several common terms throughout much of Latin America. At lower elevations sea level to about 900 metres is found the tierra caliente, or zone of warm lands, with typical tropical climatic conditions. Between 900 and 2,100 metres is found the tierra templada, or temperate zone, with conditions similar to the temperate climates typical of subtropical areas. The tierra fria, located between 2,100 and 3,000 metres, approximates the conditions found in the cold areas at the southern tip of the continent. Above the tierra fria is found the puna, or paramos country with cold conditions throughout the year. The elevations noted above are for lands near the equator. Boundaries between these zones decline the closer they are to the pole in southern Chile, for example, the snow line is at less than 1,200 metres compared to almost 5,180 metres on peaks near the equator.

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