Model results for "Robust effect of springtime Arctic ozone depletion on surface climate"

• Main Authors: Friedel, Marina, Chiodo, Gabriel
• Format: Dataset
• Language: English
• Published: ETH Zurich 2022
• Subjects: Arctic; Austral
• Online Access: https://hdl.handle.net/20.500.11850/527155; https://doi.org/10.3929/ethz-b-000527155

Massive spring ozone loss due to anthropogenic emissions of ozone depleting substances is not limited to the austral hemisphere, but can also occur in the Arctic. Previous studies have suggested a link between springtime Arctic ozone depletion and Northern Hemispheric surface climate, which might add surface predictability. However, so far it has not been possible to isolate the role of stratospheric ozone from dynamical downward impacts. Using observations and targeted chemistry-climate model experiments that allow to isolate the role of ozone depletion from dynamical downward impacts, we quantify the impact of springtime Arctic ozone depletion on surface climate. We find that springtime stratospheric ozone depletion is followed by surface anomalies in precipitation and temperature resembling a positive Arctic Oscillation. Most notably, we show that these anomalies, affecting large portions of the Northern Hemisphere, are to a substantial degree (30-60\%) driven by the loss of stratospheric ozone. The surface signal is linked to reduced shortwave absorption by ozone depletion, forcing persistent negative temperature anomalies in the lower stratosphere and a delayed breakup of the polar vortex. Moreover, we find that zonal asymmetries in the ozone distribution strengthen the surface anomalies. These results suggest that interactive ozone chemistry has the potential to substantially improve surface climate predictability on seasonal timescales. Chemistry Climate Model WACCM4