The El Nino weather pattern that several weather bureaus across the globe have forecast could emerge this summer would last at least until autumn, the Japan weather agency said on Monday.
El Nino, a warming of sea-surface temperatures in the Pacific, can trigger both floods and drought in different regions, hitting production of key foods such as rice, wheat and sugar.
Weather forecasters around the world have increasingly been predicting El Nino will return in 2014 for the first time in five years.
The Japan Meteorological Agency last month said there was a higher chance of El Nino emerging this summer, after previously forecasting a 50 per cent chance of the phenomenon, while the US federal forecaster, the Climate Prediction Centre, upped the likelihood of the weather pattern developing over the summer from 50 per cent last month to more than 65 per cent.
Scientists from the Australian Bureau of Meteorology last week also predicted a more than 70 per cent chance of the weather pattern, saying it could be strongest in decades.
The Hong Kong Observatory said last week that the arrival of El Nino could have a disruptive effect on the city’s weather by delaying the onset of the typhoon season and increasing rainfall in the winter and spring.
Dr Li Jinbao at the University of Hong Kong’s geography department also said that his research had shown that El Nino patterns have become increasingly unpredictable and associated with more extreme weather as industrialisation has gathered pace since the 1880s.
On Monday it added that El Nino would continue at least until autumn. The bureau does not typically publish predictions related to El Nino for more than six months into the future.
One of the worst El Nino events happened between 1997 and 1998, when 24,000 people were killed in weather-related disasters.
Early last month, Hong Kong experienced its heaviest hourly rainfall for March since the Observatory’s records began in 1884, leading to widespread flooding and large hailstones.
Southern Ocean winds strongest in 1,000 years: study
Winds in the wild Southern Ocean are blowing at their strongest in a millennia as climate change shifts weather patterns, leaving Antarctica colder and Australia facing more droughts, a study showed on Monday.
Rising carbon dioxide levels in the atmosphere were strengthening the winds, already dubbed the “Roaring Forties” for their ferocity, and pushing them further south towards Antarctica, researchers from the Australian National University (ANU) said.
“The Southern Ocean winds are now stronger than at any other time in the past 1,000 years,” said the study’s lead researcher Nerilie Abram of an ocean notorious for having some of the fiercest winds and largest waves on the planet.
“The strengthening of these winds has been particularly prominent over the past 70 years, and by combining our observations with climate models we can clearly link this to rising greenhouse gas levels.”
The new research, which was published in the Nature Climate Change journal, explains why Antarctica is not warming as much as other continents.
The westerly winds, which do not touch the eastern parts of Antarctica but circle in the ocean around it, were trapping more of the cold air over the area as they strengthened, with the world’s southernmost continent “stealing more of Australia’s rainfall”, Abram said.
“This is why Antarctica has bucked the trend. Every other continent is warming, and the Arctic is warming fastest of anywhere on earth,” she said.
The study’s authors analysed ice cores from Antarctica, along with data from tree rings and lakes in South America, using the southern hemisphere’s most powerful supercomputer “Raijin”, which is based at the ANU.
The research helped to explain why the westerlies were further cooling already cold parts of the continent even as they were also driving “exceptionally quicker” warming in the Antarctic Peninsula, which juts out into their path, Abram said.
Reuters and Agence France-PresseMore on this: