Climatic changes - el nino and la nina

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Credits- Ma'am Lea

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  • Climatic changes - el nino and la nina

    1. 1. Climatic Changes
    2. 2. ENSO • develops in the Pacific Ocean, • associated with extreme climatic variability; devastating rains, winds, drought, • migration, from time to time, of warm surface waters from the western equatorial Pacific Basin to the eastern equatorial Pacific region, along the coasts of Peru and Ecuador.
    3. 3. Origin • Boy Child; Little One • Anchovy Peruvian Fishermen; warm currents flowing along American Coasts during Christmas
    4. 4. Occurence • Under normal conditions, the prevailing southeasterly trade winds produce a surface current flowing toward the equator along the western South American coast. The waters leaving the coast are replace by colder waters from below (upwelling), which is rich in phytoplankton, the food source of anchovy.
    5. 5. More…. • The warm current (El Niño) temporarily displaces nutrient-rich upwelling cold water resulting in the heavy harvest of anchovies. The abundant catch, however, is shortlived. What follows is a sharp decline in the fish population , resulting in a lesser catch. At times, warming is exceptionally strong and ruins the anchovy harvest.
    6. 6. Characteristics • It occurs in the Pacific basin every 2 to 9 years; • - It usually starts during the Northern winter (December to February); • - Once established, it lasts until the first half of the following year, although at times, it stays longer; • - It exhibits phase-locking in annual cycles (El Niño and rainfall • - fluctuations associated with it tend to recur at the same time of the year; and • - It usually has a biennial cycle (El Niño events will often be preceded and/or followed by La Niña).
    7. 7. Indicators • Abnormalities such as: - delayed onset of the rainy season - early termination of the rainy season - weak monsoon activity *isolated heavy downpours with short duration - weak tropical cyclone activity *far tropical cyclone track *less no. of tropical cyclones entering the PAR *less intense tropical cyclones
    8. 8. Effects • environmental (degradation of soil which could lead to desert-like conditions if persistent, effect on water quality like salt water intrusion, high forest/grass/bus fire risk, domestic water supply shortages, etc.); • (b) social (disruption of normal human activities, migration to urban communities, human and health problems, etc.); and • (c) economic (unemployment, food shortages, significant reduction in the productivity and subsequent revenue of various industries, hydro-electric power generation, etc.).
    9. 9. La Nina – La Niña develops over the central and eastern equatorial Pacific and is characterized by unusually cold surface temperatures of the ocean. La Niña is associated with extreme climatic variability such as devastating rains, winds, drought
    10. 10. Origin • The term La Niña (the Little Girl) was used by many scientists and meteorologists to differentiate it from El Niño. It is sometimes called El Viejo (Old Man), AntiEl Niño, or simply "cold event" or "cold episode".
    11. 11. Impact • Impacts of La Niña on Philippine climate include anomalies in rainfall, temperature and tropical cyclone activities. During La Niña conditions, major parts of the country experience near normal to above normal rainfall conditions particularly over the eastern sections of the country. La Niña conditions also favor tropical cyclone formation over the western Pacific which tend to increase the number of tropical cyclones.
    12. 12. Reference • http://kidlat.pagasa.dost.gov.ph/cab/enso.htm

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