TY - JOUR A1 - Chan, E. A1 - Vet, R. J. T1 - Baseline levels and trends of ground level ozone in Canada and the United States JO - Atmos. Chem. Phys. J1 - ACP VL - 10 IS - 18 SP - 8629 EP - 8647 Y1 - 2010/09/16 PB - Copernicus Publications SN - 1680-7324 UR - https://acp.copernicus.org/articles/10/8629/2010/ L1 - https://acp.copernicus.org/articles/10/8629/2010/acp-10-8629-2010.pdf DO - 10.5194/acp-10-8629-2010 ER -