![]() ![]() May 2016, the fourth month this year to set a monthly record low, also saw ice melting far faster than historical averages. “We’re in uncharted territory, in terms of the human experience.” “It’s pretty worrisome,” says climate scientist Jennifer Francis of Rutgers University. That’s about 5 percent lower than the previous record low, set in May 2004, and more than 10 percent lower than the average sea ice extent from 1981 to 2010. National Snow and Ice Data Center on Tuesday reveal that Arctic sea ice covered an area of just 4.63 million square miles (12 million square kilometers). Satellite observations published by the U.S. Though the 2019-20 bushfires ejected smoke aerosols high into the stratosphere – the second layer in Earth’s atmosphere – the 2020 La Niña resulted from interactions between smoke and clouds in the troposphere, the lowest layer of the atmosphere, Fasullo said.Two days after Arctic sea ice hit a new record low extent for May, a new study hints at how this accelerating trend could make melting in Greenland even worse, with serious consequences for global climate and sea level rise. Incorporating wildfires into ENSO prediction systems could be beneficial, Santoso said, adding: “It seems like it is only when we have really strong bushfires that the mechanism can work.” It was not clear whether we were going to have a La Niña or not.” He added: “In 2020, the forecast for La Niña was not very reliable. But the recent La Niña … was preceded by weak El Niños in 20.” Santoso, a senior research associate at the UNSW Climate Change Research Centre, added: “Sometimes the La Niña can be prolonged if the El Niño was very strong. “Obviously it’s a huge negative to have such a strong, impactful fire, but it does provide a source of predictability perhaps.”ĭr Agus Santoso of the University of New South Wales, who was not involved in the study, said that triple La Niñas were “quite a rare event” and that the research provided a possible explanation for the most recent phenomenon which began in 2020. “With climate change, these fires are going to become bigger, more intense and longer-lasting,” he said. “Currently, there’s no forecast system that actually considers wildfire emissions, but there is the potential to include these … and improve our seasonal predictions,” he said. He said the research identified an opportunity to improve El Niño-Southern Oscillation (ENSO) forecasts, which predicts seasonal La Niñas and El Niños. We use Google reCaptcha to protect our website and the Google Privacy Policy and Terms of Service apply. For more information see our Privacy Policy. Privacy Notice: Newsletters may contain info about charities, online ads, and content funded by outside parties. It has the inverse effect in other regions, such as in the southern US where the chance of drought is increased.Ĭooler surface temperatures over the south-eastern Pacific persisted until 2022. Sign up for Guardian Australia’s free morning and afternoon email newsletters for your daily news roundupĮast-to-west equatorial trade winds strengthen in the Pacific during a La Niña, increasing the chances of above-average rainfall in the spring and summer over much of Australia and south-east Asia. “Because of that, the whole band of precipitation that usually exists in the tropics move northwards, and that’s a critical component for getting a La Niña.” “The winds became stronger as a consequence of the surface cooling off, and then the flow going into the tropics was also drier, because a cold surface means you have less humidity in the atmosphere. “Winds carried these anomalous conditions into the deep tropics, and that instigated the feedbacks that are commonly associated with La Niña,” he said. The result was a phenomenon akin to what’s known as June gloom in the US, “where you have very cold ocean conditions but very warm atmospheric conditions above this cloud layer – that’s referred to as an inversion,” Fasullo said. The net effect of that is more sunlight gets reflected back to space.” ![]() ![]() “That makes them brighter, and it also makes them live longer. Smoke particles resulted in smaller cloud droplets over the southern hemisphere, Fasullo said. “We did not expect such a strong planetary-scale signature with these fires,” he said. The study’s first author, Dr John Fasullo of the National Center for Atmospheric Research, said although the bushfire smoke only persisted in the atmosphere for several months, it triggered a long-lasting feedback loop. The research, published in the journal Science Advances, could be used to improve climate cycle predictions in future. This created favourable conditions for a La Niña to form, the researchers believe.
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