The eastward shift of the warm surface water marks the onset of El Nino Changes

The eastward shift of the warm surface water marks

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The eastward shift of the warm surface water marks the onset of El Nino. Changes in atmospheric circulation are initiated by this process affecting areas far outside the Tropical Pacific . The effects of El Nino are highly variable , depending in part on the temperatures and size of the warm pools of water.
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Pressure Changes During El Nino Seesaw pattern of atmospheric pressure occurs. 1) El Nino’s affects on the Southern Oscillation: a) Barometric pressure drops over large portions of the Southeastern Pacific. b) Barometric pressure rises over the Western Pacific. 2) When El Nino ends, the following changes occur in the Southern Oscillation: a) Barometric Pressure rises over large portions of the Southeastern Pacific. b) Barometric Pressure drops over large portions of the Western Pacific.
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El Nino and Global Weather Normal Situation A strong equatorward cold current flows along the Peruvian and Ecuadorian coasts. This cold current flows year round , except for a few weeks about Christmas time when a warm countercurrent flows. El Nino Situation Every three to seven years the warm countercurrent is unusually warm and strong . The warm countercurrent in these years is accompanied by a pool of warm, ocean surface water in the central and eastern Pacific . In Peru and Ecuador, locations that normally receive 4 to 5 inches of rain per year have as much as 140 inches in an El Nino year .
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El Nino Is part of the global circulation and affects the weather at great distances from Peru and Ecuador . For example, severe drought accompanies El Nino in Australia, Indonesia, and the Philippines. This severe drought results in huge crop losses, property damage, and human suffering. El Nino brings warm winters and wet springs to the U.S.A. (5.4 0 F (3 0 C) to 12.6 0 F (7 0 C) above normal.) California – heavy rains (bringing landslides, beach erosion, and floods). Very heavy rains in the U.S. states along the Gulf of Mexico and in Cuba. Florida has wetter winters than normal during an El Nino year .
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Consistent Effects of El Nino: 1) Warmer than normal winters in the Northern U.S.A. and in Canada. 2) Normally arid portions of Peru and Ecuador, as well as the eastern U.S.A., are wetter than normal . 3) Drought conditions persist in Australia, Indonesia, and the Philippines. 4) Fewer Atlantic hurricanes are recorded than during non-El Nino years . (These are the hurricanes that affect the Caribbean and the southern U.S.A.) El Nino has a significant influence on the state of the weather and climate almost everywhere.
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La Nina (opposite conditions to El Nino) 1) More frequent hurricane activity in the Atlantic . (The cost of hurricane damages in the U.S.A. is 20 times greater in La Nina years than in El Nino years.) 2) Cooler and wetter conditions exist over the northwestern U.S.A., and especially colder winters occur in the Northern Plains states. 3) Unusually warm conditions exist in the Southwest and Southeast states of the United States. 4) The Western Pacific is wetter than normal.
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  • Fall '16
  • Mark Smith
  • weather, Tropical cyclone, Atmospheric dynamics

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