This may not be the first time wildfire smoke has had a major impact on La Niña. Fasullo and his colleagues are currently investigating his infamous 1974-75 fire season in Australia. In 1975 and 1976, scientists predicted a warm El Niño, but when instead a cold La Niña formed, researchers called an “aborted El Niño event.” “After all, there are several cases he studies from the ’70s,” he says Mr. Fasullo. “I suspect the bushfires in Australia may have been the culprit.”
This could mean that wildfires are playing a more active role in La Niña and El Niño than previously thought. “This is especially important given that the underlying climate warming is increasing the frequency and intensity of wildfires,” says Xie. As the world gets warmer and drier, wildfires are likely to get bigger and hotter, creating more smoke that drifts across the Pacific Ocean. The smoke path from Australia is perfectly positioned to disrupt the natural variations in ocean temperatures off the coast of South America.
There is another X factor. Wildfires are just one source of atmospheric aerosols. Others result from burning fossil fuels. Like smoke, these actually help cool the planet by reflecting sunlight and acting as cloud cores. (For example, particulate pollution from cargo ships is notorious for creating cooling cloud “passages.”) But as humanity switches to green energy, less of these aerosols are produced, and wildfires are more common. smoke aerosols can be even more influential.
“There is no doubt that anthropogenic aerosols will decline, which means that these natural aerosols are likely to become more important to the climate system,” said a geoscientist at the Pacific Northwest National Laboratory. new research.
Incorporating wildfire smoke into La Niña and El Niño predictions could be more accurate. This is very important as it allows policy makers to prepare for what is to come. For example, if a La Niña causes extreme precipitation, cities should prepare their infrastructure. Also, in the event of drought, water managers will have to address potential supply issues.
Fortunately, more data and increasingly sophisticated modeling improve predictions. Back in June 2020, according to Fasullo, the National Oceanic and Atmospheric Administration actually expected neutral situation in the Pacific. “This was just a month before the longest-lasting La Niña event on record. It was kind of a historical miscalculation,” he says Fasullo. Today he says: But what this paper alone does say is that wildfires in certain circumstances offer seasonal predictability that we don’t take advantage of. ”
