Figure 5. Comparison between surface black carbon aerosol (BCA) simulated by the model and that observed by in situ measurements.

(a–c) Model-derived mass concentrations of surface BCA averaged over the final 10 days of the simulation and (filled circle) those observed by Interagency Monitoring of Protected Visual Environment (IMPROVE⁵²), China Atmosphere Watch Network (CAWNET⁵³), Canadian Aerosol Baseline Measurement website (CABM), and European Supersites for Atmospheric Aerosol Research (EUSAAR), and (d–f) the scatter plot between model-derived BCA mass and observed surface BCA mass. The open circles, triangle, square, and closed circle in (d–f) represent results for the observation site in North America, the Arctic, China, and Europe. The thin and thick grey lines in (d–f) show the range from minimum to maximum and the 25^th to 75^th percentile. All data were averaged for November 2011, except for data from CAWNET which were monthly averaged data for November 2006 and 2007. Details of the observation data are provided in Supplementary Information. The mapping of the figures was created using the Grid Analysis and Display System (GrADS)⁵¹ version 2.1.a1.