Saturday, February 20, 2016
Present El Nino 'one of the most powerful ever'
The climate pattern, which has been in effect since last year, has now peaked but will remain strong and continue to influence world weather conditions in the coming months, the World Meteorological Organisation (WMO) said.
El Nino is the result of interaction between the ocean and atmosphere in an area of the Pacific that occurs irregularly between every two and seven years, affecting the climate and increasing global temperatures.
Its peak tends to occur at the end of the calendar year - giving it its Spanish name for the Christ Child - and the 2015-16 El Nino saw eastern and central tropical Pacific temperatures more than 2C above average late last year.
While the figures provide evidence that the current El Nino is one of the strongest on record, similar to events in 1997-98 and 1982-83, it is too early to tell if it is the strongest ever recorded, the WMO said.
Last year was the hottest year on record globally, with temperatures pushed 0.76C above average by man-made climate change and the strong El Nino, and scientists warn 2016 is likely to follow suit.
WMO secretary general Petteri Taalas said: "We have just witnessed one of the most powerful ever El Nino events which caused extreme weather in countries on all continents and helped fuel record global heat in 2015.
"In meteorological terms, this El Nino is now in decline. But we cannot lower our guard as it is still quite strong and in humanitarian and economic terms, its impacts will continue for many months to come.
"Parts of South America and East Africa are still recovering from torrential rains and flooding.
"The economic and human toll from drought - which by its nature is a slowly developing disaster - is becoming increasingly apparent in southern and the Horn of Africa, central America and a number of other regions," he said.
The 2015-16 El Nino ha been linked to below average rainfall in southern Africa, including Malawi, Mozambique, Zimbabwe and South Africa, while last year's Indian monsoon was well below average.
Droughts in South East Asia helped fuel wildfires in Indonesia, causing pollution that had significant repercussions for health in the region, while El Nino also contributed to a hotter, drier year in Australia.
The phenomenon has also been linked to severe flooding in Paraguay and scientists are predicting above average rainfall in the next few months for parts of Mexico, Peru, Ecuador, Paraguay, Brazil, Uruguay and Argentina.
But parts of central America and Caribbean countries have been affected by severe drought, while El Nino is also affecting temperature and rainfall patterns in North America.
And record ocean temperatures, in part caused by El Nino, have contributed to a major coral bleaching event, a process which damages and destroys coral reefs and affects the species and people that rely on them.
El Niño passes its peak while La Niña is possible this year
The El Niño weather phenomenon has reached its peak according to scientists and is set to decline over the next few months.
Researchers say there is a 50:50 chance that it will be replaced by a La Niña event before the end of this summer.
La Niña which involves a cooling of the Pacific Ocean, usually brings wetter conditions to Asia, Africa and Latin America.
These events can typically last twice as long as an El Niño.
Warmest January on record
While the World Meteorological Organisation (WMO) reports that the El Niño event has reached its apex, it is still having a significant influence on the global climate.
In combination with human induced warming, global temperatures in January were the hottest for the month since records began in 1880. The data also showed the biggest divergence yet seen from the long term record.
"In meteorological terms, this El Niño is now in decline. But we cannot lower our guard as it is still quite strong and in humanitarian and economic terms, its impacts will continue for many months to come," said Petteri Taalas from the WMO.
"Parts of South America and East Africa are still recovering from torrential rains and flooding. The economic and human toll from drought - which by its nature is a slowly developing disaster - is becoming increasingly apparent in southern and the Horn of Africa, central America and a number of other regions," he said.
While the El Niño did bring some relief to drought-hit California, there have been concerns that it has tapered off in recent weeks.
But in the wake of El Niño, experts believe there is a good chance that a La Niña will arrive later this year .
"Most models indicate that El Niño will weaken, with a transition to neutral during the late spring or early summer 2016," according to the US Climate Prediction Centre.
"Thereafter, the chance of La Niña conditions increases into the autumn," they concluded.
According to the US National Oceanic and Atmospheric Administration (NOAA), there is a 50% chance of a La Niña this summer. They say that there is an 80% chance of it happening by the end of this year.
Not every weather centre is on the same page when it comes to predicting the appearance of the event that's also termed El Viejo (the old one) or the Anti-El Niño .
Australia's Bureau of Meteorology says that based on 26 El Niño events since 1900, around half have been followed by a neutral year while 40% have been followed by La Niña. They argue that international climate models right now suggest that there won't be a follow-on La Niña this year.
If forecaster are a little uncertain of the arrive of a La Niña, they are all remaining tight-lipped on the more important question of how powerful it is likely to be.
La Niña often improves fishing conditions in the Pacific Ocean off South America, thanks to the upwelling of cold, nutrient-rich waters.
It is also associated with heavier monsoons in South-East Asia, but it has also caused significant flooding in Australia in the recent past.
Another outstanding question is the impact of climate change on La Niña. A study last year suggested that extreme events were much more likely in a warming world.
By Matt McGrath
Posted by wikisabah at 2:59:00 PM