Potential Source Regions and Transportation Pathways of Reactive Gases at a Regional Background Site in Northwestern China

<div>Time series changes in the hourly averages of O<sub>3</sub>, CO, NO<sub>2</sub>, and SO<sub>2</sub> on the ground during the observation period from September 2017 to August 2018. The black circle is the hourly average, the thin red line is the 24-hour smoothening, and the blue thick solid line is the 30-day smoothening.</div>

Advances in Meteorology

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Figure 2

Figure 2: Potential Source Regions and Transportation Pathways of Reactive Gases at a Regional Background Site in Northwestern China 