In the Southern Hemisphere spring of 2019 the usually very strong winds in the stratosphere, about 186 mph (300 km/h) at a height of 18.6 miles (30 km) almost completely collapsed within a matter of days —a so-called Sudden Stratospheric Warming (SSW) was underway. These events high in the atmosphere are known to influence the wind structure at the surface and cause anomalous weather conditions at the ground. The stratosphere affects surface weather and climate on a global scale, and ongoing global warming leads to major changes of this influence.
That’s why in early September, the stratospheric research community argued that something very rare was happening and might make things much worse.
Unfortunately, the researchers were right.
The spring of 2019 was exceptional for Australia: Scorching heat, the culmination of a three-year drought, and bushfires raging much earlier in the season than any other time in recorded history. By summer, the burning and related loss of flora, fauna and human lives, as well as respiratory health impacts, were at a disastrous scale. While the reasons for this devastating natural catastrophe were many—and still are subject to intensive research—a new study in Geophysical Research Letters shows how rare one of the main contributors to that extreme fire weather was, and how in a future warmer world it will become even rarer to the point of being almost impossible.
Read more at: University of Utah
Photo Credit: Free-Photos via Pixabay