Figure 1
Validation of the model calculated near-surface BaP concentrations against observations in the field.
The downscaling is conducted for non-background grids with strong spatial variations. (a) Validations at 18 background sites. (b and c) Validations at 236 non-background sites without and with downscaling, respectively. Sites in different regions are marked with different colours. The areas of the bubbles are proportional to observation durations, so more reliable observations are carried in larger bubbles. 1:1 lines are drawn in blue. Residuals are defined as the differences between log-transformed observations and calculations and the calculated means (M), standard deviations (SD) and square sums (RSS) of residuals are listed in (a), (b) and (c). (d and e) Time series at Kosetice background and Radebeul non-background stations. The calculated and observed concentrations are shown as blue and purple lines, respectively. The model calculations at Radebeul non-background site are downscaled. The model uncertainties as 95% confidence intervals are shown by shaded areas. The comparisons of time series for all other six background stations and one non-background station can be found in the Supplementary Figs. S3–S5.
