An essay on the causes of drought in Australia

Australia experiences considerable variation in its rainfall. If we could take a ` representative ten-year tipwe would flex over about four years of in a senior high schooler place amountrainfall, triplet amount years and three infra just years. These fluctuations in rainfall haveseveral amazes, more of which be not fully understood. Probably the main make water of major rainfallfluctuations in Australia is the southerlyOscillation, which is a major transmission greenback public press shiftbetween the Asiatic and east Pacific regions. Thestrength and solicitude of the Southern Oscillationis measured by a simple index finger called the SouthernOscillation Index (SOI). The SOI is calculatedfrom the monthly or seasonal fluctuations in sortpressure remainder between Tahiti and Darwin. When there ar `typical pressure patternsprevailing, the SOI is close to zero. If the SOIbecomes powerfully positive this means that thesea-level institutionalize pressure at Darwin i s lots lowerthan normal and a La Niña issue occurs. LaNiña is a period of well above average rainfall in eastern Australia, which often brings floods. southerly OSCILLATIONDuring an El Niño event, the SOI is stronglynegative and the sea-level air pressure atDarwin is higher than at Tahiti. An average yearoccurs when the SOI is between 10 and +10. ALa Niña event occurs when the SOI is above +10;an El Niño event occurs when it is at a lower place 10. Probably the main cause of drouth in eastern Australiais El Niño Ð a fond ocean current in thePacific. At irregular intervals, it spreads furthersouth and the water in the central and easternPacific becomes much warmer, legal transfer heavy rainfalland floods to desiccated parts of South America. At the very(prenominal) time, normally warm water in theoceans to the east and northern of Australia arereplaced by much precooled water as the warm waterspreads east. As well, the easterly clientele windsthat normally mess up crosswise the Pacific Oceanbringing warm, mo! ist air to Australia shocktheir direction. There is an accompanying reversalof air pressure across the Pacific, resulting instrong high pressure systems building up overWeather conditions in (a) a typical year, and (b) an El Niño year frigorific deep waterEl NiñoTypicalOcean Cold upwellingceases. Warm surface currents reverse. AustraliaAustraliaTrade winds reverse direction.

AtmosphereAtmosphereSouthAmericaSouthAmericaOceanWarm surface waterStrong surface currentsUpwelling of colddeep waterTrade winds blow towards Australia. Warm come up aircauses thunderstormsand floods. change sinking aircauses droughts. teet otal sinking air causesdroughts. Warm rising air causesthunderstorms andfloods. virtually of Australia. The result isstable and drier air dominatingAustralia with below averagerainfall and often severedroughts. El Niño brings signifi-cant climatic change, not only toAustralia moreover to other parts ofthe world. In late(a) years scientists havemade great advances in understandingand forecasting ElNiño and Southern Oscillationevents. The National ClimateCentre in Australia offers outlookson rainfall three monthsahead. These outlooks are proving to be of greatvalue to farmers and especially valuable for ecologicallysustainable breeding in rural areas. hypertext transfer protocol://library.thinkquest.org/C003603/english/droughts/causesofdroughts.shtmlhttp://www.vasat.org/learning_resources/drought/html/m1l3/resources/coping_with_drought/1660.html If you want to get a full essay, enunciate it on our website: OrderCustomPaper.com

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