Abiotic Factors Influencing The Distribution Of Biomes Case Study

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One of the main abiotic factors influencing the distribution of biomes is global atmospheric circulation. Global atmospheric circulation is the mass movement of air around earth caused by thermal energy. This mass movement of air causes three distinct atmospheric circulation cells to form, these are the Hadley Cell, Ferrel Cell and Polar Cell. Between these three cells is a dynamic area called the Intertropical Convergence Zone.
Persson (2006) tells us that the Hadley Cell is caused by solar energy heating the equator, this causes warm moist air to rise towards the Tropopause dumping rain in terrestrial biomes such as the Tropical Rainforest. After the air has risen and lost most of its moisture it travels along the troposphere whilst being
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The ITCZ is caused by the convectional rise of moist air at the start of the Hadley Cell creating a humid low pressure area between the two cells. This uplift of warm humid air creates the highest levels of precipitation on earth, this influences the characteristics and distribution of the Tropical Rainforest. Tapio Schneider, Tobias Bischo & Gerald H. Haug (2014) explain that the Intertropical Convergence Zone is dynamic and moves further north during the Northern Hemisphere summer and south during the Southern Hemisphere summer. Usually when the ITCZ is on land it will move further due to larger temperature shifts. The dynamic nature of the ITCZ gives heavy seasonal rainfall to biomes such as the Tropical Deciduous Forest and Tropical …show more content…
As discussed, the lower latitudes of the Hadley Cell and the ITCZ are humid low pressure areas where moist air is rising upwards from the equator, creating large amounts of precipitation, this is explained by Arbogast (2014). Like deserts, tropical rainforests can often be caused by a rain shadow, however rainforest are found on the opposite side of a mountain range to a desert. Research done by Edward K. Vizy and Kerry H. Cook (2006) explains an example of this in the Amazon Basin in South America. Moist prevailing easterly trade winds from the Hadley Cell and ICTZ move from the Atlantic Ocean towards South America, they precipitate over the low altitude Amazon Basin before rising up to the Andes Mountains, this forms the Atacama Desert on the leeward side. This large amount of precipitation is a key characteristic of a tropical rainforest. Michael L. McKinney, Robert M. Schoch & Logan Yonavjak (2007) explains that a Tropical Rainforest typically receives over 2000mm of rain a year. Being so close to the equator the amount of daylight hours during a twenty four hour period doesn’t vary through the year, because of this rainforests receive over 4400 daylight hours per year. Being so close to the equator with high sunshine hours the temperature of a tropical rainforest is consistently around 25 degrees. This high rainfall, high sunshine hours and moderate to high

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