The Arctic Ozone Hole in March 2020 and Its Seasonal Prediction in
CFSv2: A Comparative Study with the 1997 and 2011 Arctic Ozone Holes
Abstract
Using reanalysis data, observations, and seasonal forecasts, the March
Arctic ozone hole events in 1997, 2011, and 2020 and their
predictability are compared. All of the three ozone hole events were
accompanied by an extremely strong and cold polar vortex. The shape and
centroid of the ozone holes are mainly controlled by the simultaneous
polar vortex. The March 2020 ozone hole was displaced towards Canada and
Greenland, the March 2011 ozone low was evenly distributed over the
North Pole, while the 1997 ozone hole was displaceds toward Arctic
Russia. The predictability of the 2011 ozone hole event is longer (1–2
months) than the other two (~1 month) possibly due to La
Niña and Quasi-Biennial westerly winds, favorable for formation of a
strong polar vortex. Surprisingly, an empirical model using a substitute
index to forecast the Arctic ozone might be as skillful as the general
circulation model with a chemistry module.