el-nino

El Nino menyerang kembali.. cuaca skrg kejap panas kejap hujan... yg paling tak tahan JEREBU!!! sungguh tak kusangka jerebu sgt tebal di Putrajaya... patutlah ramai yg sakit tekak, demam, flu pelbagai.. rupe2nyer.. buka mata pagi2 nampak jerebu shj! So, i telah merajinkan diri utk membaca sedikit sebanyak info on El Nino, i copy je dr wikipedia ke sini.. koang baca lah yerk, menambah kan pengetahuan!

From wikipedia:

El Niño-Southern Oscillation (ENSO; commonly referred to as simply El Niño) is a global coupled ocean-atmosphere phenomenon. The Pacific ocean signatures, El Niño and La Niña are important temperature fluctuations in surface waters of the tropical Eastern Pacific Ocean. The name El Niño, from the Spanish for "the little boy", refers to the Christ child, because the phenomenon is usually noticed around Christmas time in the Pacific Ocean off the west coast of South America.[1] La Niña, similarly, means "the little girl". These effects were first described in 1923 by Sir Gilbert Thomas Walker from whom the Walker circulation, an important aspect of the Pacific ENSO phenomenon, takes its name. The atmospheric signature, the Southern Oscillation (SO) reflects the monthly or seasonal fluctuations in the air pressure difference between Tahiti and Darwin, Australia. The most recent occurrence of El Niño started in September 2006[2] and lasted until early 2007.[3] From June 2007 on, data indicated a weak La Niña event, strengthening in early 2008 and weakening in late 2008, with a forecast return to neutral conditions in 2009.
ENSO is associated with floods, droughts, and other disturbances in a range of locations around the world. These effects, and the irregularity of the ENSO phenomenon, makes predicting it of high interest. Significant advances in the predictability of ENSO were contributed by Stephen Zebiak and Mark Cane.[4] ENSO is the most prominent known source of inter-annual variability in weather and climate around the world (about 3 to 8 years), though not all areas are affected. ENSO has signatures in the Pacific, Atlantic and Indian Oceans.
During major warm events, El Niño warming extends over much of the tropical Pacific and becomes clearly linked to the intensity of the Southern Oscillation. While ENSO effects are basically in phase between the Pacific and Indian Oceans, ENSO effects in the Atlantic Ocean lag behind those in the Pacific by 12 to 18 months. Many of the countries most affected by ENSO are developing countries that are largely dependent upon their agricultural and fishery sectors for food supply, employment, and foreign exchange.
New capabilities to predict the onset of ENSO events can have global socio-economic impacts. While ENSO is a natural part of the Earth's climate, an important concern is whether its intensity or frequency may change as a result of global warming. Low-frequency variability has been evidenced; interdecadal modulation of ENSO from the Pacific Decadal Oscillation (PDO) or the Interdecadal Pacific Oscillation (IPO) might exist. This could explain the so-called protracted ENSO of the early 1990s.

The first signs of an El Niño are:
1. Rise in surface pressure over the Indian Ocean, Indonesia, and Australia
2. Fall in air pressure over Tahiti and the rest of the central and eastern Pacific Ocean
3. Trade winds in the south Pacific weaken or head east
4. Warm air rises near Peru, causing rain in the northern Peruvian deserts
4. Warm water spreads from the west Pacific and the Indian Ocean to the east Pacific. It takes the rain with it, causing extensive drought in the western Pacific and rainfall in the normally dry eastern Pacific.

Wider effects of El Niño conditions
See also: Effects of the El Niño-Southern Oscillation in the United States
Because El Niño's warm pool feeds thunderstorms above, it creates increased rainfall across the east-central and eastern Pacific Ocean.
The effects of El Niño in South America are direct and stronger than in North America. An El Niño is associated with warm and very wet summers (December-February) along the coasts of northern Peru and Ecuador, causing major flooding whenever the event is strong or extreme. The effects during the months of February, March and April may become critical. Southern Brazil and northern Argentina also experience wetter than normal conditions but mainly during the spring and early summer. Central Chile receives a mild winter with large rainfall, and the Peruvian-Bolivian Altiplano is sometimes exposed to unusual winter snowfall events. Drier and hotter weather occurs in parts of the Amazon River Basin, Colombia and Central America.
Direct effects of El Niño resulting in drier conditions occur in parts of Southeast Asia and Northern Australia, increasing bush fires and worsening haze and decreasing air quality dramatically. Drier than normal conditions are also generally observed in Queensland, inland Victoria, inland New South Wales and eastern Tasmania from June to August.
West of the Antarctic Peninsula, the Ross, Bellingshausen, and Amundsen Sea sectors have more sea ice during El Niño. The latter two and the Weddell Sea also become warmer and have higher atmospheric pressure.
In North America, typically, winters are warmer than normal in the upper Midwest states, the Northeast, and Canada, while central and southern California, northwest Mexico and the southwestern U.S., are wetter and cooler than normal. Summer is wetter in the intermountain regions of the U.S. The Pacific Northwest states, on the other hand, tend to experience dry but foggy winters and warm, sunny and precocious springs during an El Niño. During a La Niña, by contrast, the Midwestern U.S. tends to be drier than normal. El Niño is associated with increased wave-caused coastal erosion along the US Pacific Coast and decreased hurricane activity in the Atlantic, especially south of 25º N; this reduction is largely due to stronger wind shear in the tropics.
Finally, East Africa, including Kenya, Tanzania and the White Nile basin experiences, in the long rains from March to May, wetter than normal conditions. There also are drier than normal conditions from December to February in south-central Africa, mainly in Zambia, Zimbabwe, Mozambique and Botswana.