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Australia is so large that its climate varies. The greater part of the continent is desert or semi-arid. Only the south-east and south-west corners have a temperate climate and moderately fertile soil. The northern part has a tropical climate, varied between tropical rainforests, grasslands, and part desert. Australia's climate is governed by the hot, sinking air of the subtropical high pressure belt. This moves north and south with the seasons, so that the rainfall pattern over Australia is highly seasonal. Australia's rainfall is the lowest of the seven continents (besides Antarctica). But it is variable, with frequent droughts lasting several seasons—thought to be caused in part by the El Niño-Southern Oscillation. Because Australia is a small continent, separated from polar regions by the Southern Ocean, it is not subject to the movements of frigid polar air that sweep over Northern Hemisphere continents during winter. Consequently, its winter is relatively mild, so that there isn't the great contrast between summer and winter temperatures there is in the northern continents. Yet in many parts of the country, seasonal highs and lows can be considerable: temperatures have ranged from above to well below zero. Nonetheless, minimum temperatures are moderated owing to the lack of mountains and the influence of surrounding oceans. The El Niño-Southern Oscillation is associated with seasonal abnormality in many areas in the world. Australia is one of the continents most affected and experiences extensive droughts alongside considerable wet periods. Occasionally a dust storm will blanket a region and there are reports of the occasional tornado. Tropical cyclones, heat waves, bushfires and frosts in the country are also associated with the Southern Oscillation. Rising levels of salinity and desertification in some areas is ravaging the landscape. Climate change in Australia is a highly contentious issue. Temperatures in the country have risen following an increasing trend of global warming between the years of 1910 to 2004 by approximately 0.7 °C. Overnight minimum temperatures have warmed more rapidly than daytime maximum temperatures in recent years. The late-20th century warming has been largely attributed to the increased greenhouse effect.〔http://www.abs.gov.au/Ausstats/abs@.nsf/94713ad445ff1425ca25682000192af2/bbd307d0202ca25bca2570de00032610!OpenDocument#CLIMATE%20CHANGE〕 According to the Bureau of Meteorology, 80% of the land has less than of rainfall per year and 50% has even less than .〔(Climate of Australia )〕 As a whole, Australia has a very low annual average rainfall of . ==Precipitation== 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Climate of Australia」の詳細全文を読む スポンサード リンク
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