The South Pole has warmed up three times faster than the rest of the planet in the past 30 years due to warmer tropical ocean temperatures, according to new research on Monday.
The temperature of Antarctica varies widely depending on the season and region and for years the South Pole was thought to have remained cool even as the continent warmed up.
Researchers in New Zealand, Britain and the United States analyzed 60 years of weather station data and used computer modeling to show what was causing accelerated warming.
They found that warmer ocean temperatures in the western Pacific have lowered the atmospheric pressure over the Weddell Sea in the southern Atlantic over the decades.
This in turn had increased the flow of hot air directly over the South Pole, heating it by over 1
The authors of the research said that the trend to natural warming was probably stimulated by human-produced greenhouse gas emissions and could mask the warming effect of carbon pollution on the South Pole.
“While temperatures were known to warm across Western Antarctica and the Antarctic Peninsula during the 20th century, the South Pole was cooling down,” said Kyle Clem, a researcher at Victoria University of Wellington and lead author of the study. .
“It was suspected that this part of Antarctica … could be immune / isolated from warming. We found out that this is no longer the case,” he told AFP.
Data showed that the South Pole – the most remote point on Earth – has now been warming at a rate of about 0.6 ° C (1.1 ° F) for a decade, compared to about 0.2 ° C ( 0.4 ° F) for the rest of the planet.
The authors of the study, published in Nature Climate change journal, attributed the change to a phenomenon known as the Interdecadal Pacific Oscillation (IPO).
The IPO cycle lasts about 15-30 years and alternates between a “positive” state – in which the tropical Pacific is warmer and the northern Pacific is colder than average – and a “negative” state in which the anomaly of the temperature is reversed.
At the beginning of the century, the IPO began a negative cycle, leading to greater convection and more extremes of pressure at high latitudes, leading to a strong flow of warmer air just above the South Pole.
Clem said the 1.83 ° C (3.3 ° F) warming level exceeded 99.99% of all modeled trends in thirty-year warming.
“While the warming was right within the natural variability of climate models, human activity was very likely to have contributed,” he said.
© Agence France-Presse