El Nino and La Nina

formation of El Nino

-trade winds reverse and weaken and start to blow east east instead of west -warm water sloshes easterly, back toward Pacific -water is not moved away from the coast of South America so no or weakened up welling of cold, nutrient rich, bottom water occurs, -rainy, warm and low pressure on eastern side of Pacific -cooler and clear on western part of pacific

El Nino

-(oceanography) a warm ocean current that flows along the equator from the date line and south off the coast of Ecuador at Christmas time -a climate variation that takes place in the tropical Pacific about every three to seven years, for a duration of about one year.

La Nina

-A cooling of the ocean surface off the western coast of South America, occurring periodically every 4 to 12 years and affecting Pacific and other weather patterns. "Normal" year, easterly trade winds and ocean currents pool warm water in the western Pacific, allowing upwelling of nutrient rich water off the West coast of South America.

formation of La Nina

-typical easterly trade winds weaken -this pushes even more warm surface water away from the coast and toward the west, making room for even stronger up welling of cold water -warm water piles up on western side of the Pacific near Australia. Rainy and warm weather, low pressure. -Eastern side of pacific, off the coast of south america, cool, clear weather, high pressure -good for fishing industry

What type of climate pattern do we see with La Nina?

In the US, La Nina is expected to bring above normal temperatures throughout most of the Southwest and southern Florida in the late summer and fall. These warmer conditions will extend across the Southeast during the winter months. Cooler than normal winter temperatures are expected in the Pacific Northwest. Cooler than normal temperatures are also expected across the Great Lakes and Northeast later in the winter into spring. It also affects rainfall, drier than normal conditions will persist in west Texas, New Mexico and Arizona into October.

What type of climate change do we experience with El Nino in the United States?

The climate pattern can change the weather of the US, particularly in California and the southern states. Usually, El Nino brings more rain and higher temperatures. Also, warm ocean currents come farther north and all kinds of tropical fish can be caught in the waters far north along the US west coast. El Nino may also bring warmer than normal winters temperatures to the eastern part of the US.