El Nina and La Niña
Geography
In this essay I will be discussing the economic, environmental and social effects of El Niño and La Niña on Africa. El Niño and La Niña events are a natural part of the global climate system. They happen when the Pacific Ocean and the atmosphere above it change from their normal state for several seasons. El Niño events cause warming of the central and eastern tropical Pacific, while La Niña events cause the opposite, with the cooling of the same areas. La Niña causes wet conditions in Southern Africa from December to February, and dry conditions over equatorial East Africa over the same period.
Winds blowing from east to west cause a large amount of warm surface water to gather west in the Pacific Ocean. The warmer water is about 8 degrees Celsius higher than in the eastern Pacific. As the warm water moves west, cold nutrient rich water rises to the surface in South America. This cold water causes a opportunity for good fishing. In the west the warmer water evaporates easily which brings lots of rainfall that causes crops to grow well, feeding many people and helping the economies of nations.
El Niño can cause an epidemic of diseases. Most commonly are the diseases transmitted by mosquitoes, like malaria, dengue, and Rift Valley fever. A large outbreak of Rift Valley fever happened after extreme rainfall in north-eastern Kenya and southern Somalia during the 1997–98 El Niño. The Earth Institute of Columbia University, after looking at data from 1950 to 2004, claims El Niño may have affected 21% of all the fighting since 1950. The risk of people fighting is doubled from 3% to 6% in countries affected by El Niño during El Niño years relative to La Niña years.
Generally El Niño and La Niña have more of an effect on country's outside of Africa, rather than the country's inside. Within Africa El Niño and La Niña have more of an effect up north, with Southern Africa only having a slight effect.
In this essay I will be discussing the economic, environmental and social effects of El Niño and La Niña on Africa. El Niño and La Niña events are a natural part of the global climate system. They happen when the Pacific Ocean and the atmosphere above it change from their normal state for several seasons. El Niño events cause warming of the central and eastern tropical Pacific, while La Niña events cause the opposite, with the cooling of the same areas. La Niña causes wet conditions in Southern Africa from December to February, and dry conditions over equatorial East Africa over the same period.
Winds blowing from east to west cause a large amount of warm surface water to gather west in the Pacific Ocean. The warmer water is about 8 degrees Celsius higher than in the eastern Pacific. As the warm water moves west, cold nutrient rich water rises to the surface in South America. This cold water causes a opportunity for good fishing. In the west the warmer water evaporates easily which brings lots of rainfall that causes crops to grow well, feeding many people and helping the economies of nations.
El Niño can cause an epidemic of diseases. Most commonly are the diseases transmitted by mosquitoes, like malaria, dengue, and Rift Valley fever. A large outbreak of Rift Valley fever happened after extreme rainfall in north-eastern Kenya and southern Somalia during the 1997–98 El Niño. The Earth Institute of Columbia University, after looking at data from 1950 to 2004, claims El Niño may have affected 21% of all the fighting since 1950. The risk of people fighting is doubled from 3% to 6% in countries affected by El Niño during El Niño years relative to La Niña years.
Generally El Niño and La Niña have more of an effect on country's outside of Africa, rather than the country's inside. Within Africa El Niño and La Niña have more of an effect up north, with Southern Africa only having a slight effect.