Fig. 5: The time series of trace gas concentrations in Beijing and Hyytiälä.
From: Understanding atmospheric processes: insights from the comparison between Beijing and Hyytiälä

Concentrations of (a) NO, (b) NOx, (c) SO2, and (d) CO in Beijing (red) and Hyytiälä (blue) are shown, respectively. Hourly mean datasets from 2018 to 2022 were used.