According to a senior climate scientist at the Bureau of Meteorology, even if El Nio does not develop this year, Australians should still be prepared for a summer full of heatwaves due to the likelihood that they will occur.
This year “could be significant in terms of heatwaves and fires,” according to Dr. Karl Braganza, the national manager for climate services at the bureau. However, it is unlikely to duplicate the horrors of the black summer bushfires that occurred in 2019-2020.
According to him, the fact that the temperatures in the world’s oceans are currently breaking records for warmth could be one of the reasons why El Nio has not yet formed.
According to him, “Historically speaking, we have never seen a situation like this before entering an El Nio event with record global ocean temperatures.”
El Nio is characterized by increased ocean temperatures in the equatorial Pacific, which have the effect of reducing the strength of the trade winds that blow from east to west over the ocean. This climate pattern has the potential to drive droughts and heat in Australia, in addition to contributing to increase in the average global temperatures.
Even though the World Meteorological Organization and the United States National Oceanic and Atmospheric Administration have already declared that an El Nio is occurring, the Bureau of Meteorology reported this week that the atmosphere was still not giving a consistent signal that was typical of an El Nio. In particular, the changes in the trade winds were not occurring.
According to the most recent long-range forecast issued by the bureau on Thursday, the majority of the United States is projected to have temperatures that are higher than usual through the month of October, along with lower-than-average rainfall.
According to Braganza, the projection will be accurate regardless of whether or not an El Nio event occurs. He stated that if El Nio was declared, it would give the bureau more confidence that the outlook would continue to be largely warm and dry during the rest of the summer. This was in reference to the time period after October.
According to Braganza, if you were to look at El Nios that occurred in the past, you would normally observe a tongue of warm ocean water extending from the west coast of Central America all the way across the equatorial Pacific.
This would typically be surrounded by a horseshoe-shaped band of cooler water off the northeastern coast of Australia, which causes a reversal in the direction of the trade winds and secures the El Nio in place.
Braganza was quoted as saying, “This does not look like that canonical El Nio.” “At the moment, the tropical Atlantic is extremely warm, while the western Pacific and the Indian Ocean both have a fairly warm temperature.”
Large-scale weather patterns like El Nio can be driven in part by differences in temperature that exist throughout different sections of the ocean, yet, at this moment, the majority of the ocean was warm.
According to Braganza, this widespread setting of new records for ocean temperatures “could be making it harder for the El Nio to get going in the atmosphere.” He referred to this possibility as a “point of conjecture.”
“The bottom line is that we are adding heat to the ocean, and that has to be modulating the ocean’s natural variability to some degree,” the author writes, “but we don’t have a clear scientific understanding of that at the moment.”
Braganza stated that because of changes in the climate around the world, it had become more difficult to make accurate predictions based on previous occurrences.
According to the bureau’s most recent forecast, there is still a 70 per cent possibility that an El Nio may form later this year.
According to Braganza, the forecasts were also predicting that another phenomenon in the Indian Ocean that can diminish rainfall was anticipated to emerge throughout the course of spring. Braganza stated that “we will likely strengthen our forecast advice” in the event that this transpires in conjunction with the establishment of an El Nio.
After three years in a row of unusually rainy summers brought on by La Nia, some climate scientists and bushfire experts are concerned that there is now a lot of grass and vegetation that might create fuel for fires. This is due to the fact that there has been a lot of rainfall over the past three years.
“The fuel growth is remarkable, and in our newly developed climate system, how quickly can we dry out that fuel?” According to Braganza.
“You would say that it won’t be as bad as the disaster that happened in 2019, but our advice is that you should get ready for a summer that might be big in terms of heatwaves and flames. But I’m not as concerned as I would be if we’d been in a drought for two consecutive years.”
He stated that a reduction in the amount of sea ice had the potential to lead to changes in the wind and weather patterns.
“What we are seeing now as a result of the lack of growth is that instead of sea ice extending into the mid-latitudes, you now have dark ocean. This is the result of the lack of growth.” This results in a shift in the equilibrium of solar radiation in the southern hemisphere.
