Using a pattern-based detection and attribution analysis of atmospheric zonal wind, scientists show that the pause in circulation trends is forced by human activities, and has not occurred owing only to internal or natural variability of the climate system.
Above: The ozone hole on September 8, 2019, the lowest maximum observed in decades. Credit NASA
Here we show that these widely reported circulation trends paused, or slightly reversed, around the year 2000.
Ian Rae, organic chemist from the University of Melbourne who was not involved in the study, explains:
“The ‘weather bands’ that bring our cold fronts have been narrowing towards the south pole, and that’s why southern Australia has experienced decreasing rainfall over the last thirty years or so. If the ozone layer is recovering, and the circulation is moving north, that’s good news on two fronts (pun not intended).”