Fingerprints of the COVID-19 economic downturn and recovery on ozone anomalies at high-elevation sites in North America and western Europe oleh D. Putero, P. Cristofanelli, K.-L. Chang, G. Dufour, G. Beachley, C. Couret, P. Effertz, D. A. Jaffe, D. Kubistin, J. Lynch, I. Petropavlovskikh, M. Puchalski, T. Sharac, B. C. Sive, M. Steinbacher, C. Torres, O. R. Cooper