Wednesday, December 22, 2010

Deadly La Niña goes global

Aubrey Ann Parker and Steve Kellman in Circle of Blue Waternews: The weather phenomenon known as La Niña is having wide-ranging impacts around the Pacific basin, as Colombia copes with record rains and New Zealand swelters through a heat wave. The El Niño Southern Oscillation (ENSO) climate pattern is a coupled ocean-atmosphere phenomenon consisting of El Niño and La Niña cycles. This year is being classified as a moderate-to-strong La Niña, following 2009’s especially intense El Niño year.

La Niña causes colder than usual water currents along the Pacific coast of the Western Hemisphere, which has caused a severe rainy season from May through November in Mexico, Central America, and the northern part of South America. According to the United Nations Environmental Programme, although ENSO is naturally occurring, a warming climate may contribute to an increase in frequency and intensity of El Niño cycle. La Niña events double the likelihood of intense weather events, such as hurricanes and tropical storms, for much of the Caribbean and the Gulf of Mexico.

In November, rainfall in the Caribbean was five times the average of 2 inches and in the central highlands of Colombia, rainfall was more than double the average of 3.5 inches. In Colombia, this year’s rainy season—the worst in 42 years—has been exceedingly severe, with close to 300 deaths and more than 2 million people affected over the last two months, according to the BBC.

…With close to 2.5 million acres of farmland and over 600 schools under water, the damage in Colombia is estimated at $5 billion. The United States, the European Union, North Korea, and Switzerland have pledged more than $20 million in aid. After visiting neighbor Venezuela, which has also had particularly severe flooding this winter, the Ecuadorian visited Colombia and vowed to help, thus restoring diplomatic relations, which have been strained since Colombia’s 2008 military raid on a clandestine Colombian guerrilla camp just inside Ecuadorian territory.

…La Niña tends to result in dryer and warmer conditions across much of the southern tier of the United States and wetter weather across the Midwest, Pacific Northwest, and the Northern Rockies, according to the National Oceanographic and Atmospheric Administration (NOAA). The flip side of the weather pattern, El Niño, occurs when water temperatures in the equatorial Pacific are warmer than average and results in nearly the opposite effects….

Roelant Savery's 1620 painting of Noah's Ark, shot by Dorota Folga-Januszewska (2005). Muzeum Narodowe w Warszawie : arcydzieła malarstwa. Arkady. ISBN 83-21343-31-7