What caused massive Arctic ozone hole in 2020? This study has some answers
In 2020, a new and rather unusually large hole in the ozone layer was formed over the Arctic now, scientists have finally established the possible reason behind it. The analysis proposed that the large hole in the ozone layer was likely caused by the record-high sea surface temperatures (SSTs) in the North Pacific.
Scientists from the Department of Atmospheric and Oceanic Sciences, School of Physics at Peking University, led by Prof. Yongyun Hu plugged satellite data into a series of simulations and found that the record Arctic ozone loss was associated with the extremely cold and persistent stratospheric polar vortex over February to April.
The extremely cold vortex was a result of "anomalously weak planetary wave activity" as the analysis, which is published in Advances in Atmospheric Sciences, revealed that the weak wave activity can be traced to anomalously warm SSTs in the North Pacific.
It is known that the Arctic stratospheric vortex is typically too warm for polar stratospheric clouds to form, which are a key ingredient in severe ozone depletion processes but still polar meteorologists reported a record-breaking Arctic "ozone hole" during spring 2020 that piqued researchers to investigate about it.
"The record-high North Pacific sea surface temperatures during February and March 2020 led to a large reduction of wavenumber-1 wave activity by modifying the Aleutian low," Prof. Hu explained.
"The reduction of planetary wave activity caused the extremely cold and persistent stratospheric polar vortex between February and April 2020 which provided the necessary conditions for severe ozone loss," Hu added.
"The formation of the record Arctic ozone loss in spring 2020 indicates that present-day ozone depleting substances are still sufficient to cause severe springtime ozone depletion in the Arctic stratosphere," said Prof. Hu.
"These results suggest that severe ozone loss is likely to occur in the near future as long as North Pacific warm SST anomalies or other dynamical processes are sufficiently strong," Prof. Hu added.