World ‘Unprecedented’ Arctic ozone hole closed, but not because of coronavirus, scientists say April 28, 2020N'dea Yancey-Bragg and Doyle Rice, USA TODAYComments Off on ‘Unprecedented’ Arctic ozone hole closed, but not because of coronavirus, scientists say This spring, an "unprecedented" ozone hole formed over the Arctic thanks to an unusually strong polar vortex. Now it's gone.