Fig. 2: The potential source contribution function (PSCF) analysis of air pollutants and meteorological field changes during the observation period.

The PSCF analysis of VOCs (a), O3 (b), and the field of geopotential height and wind (c) before CNY. d–f The PSCF analysis of VOCs (d), O3 (e), and the field of geopotential height and wind (f) during CNY, respectively. g–i The PSCF analysis of VOCs (g), O3 (h), and the field of geopotential height and wind (i) after CNY, respectively. The color bar in the left (a, d, g) and middle (b, e, h) columns indicates the possibility of the source, ranging from 0 to 1. The geopotential height in the right column (c, f, i) is at 925 hPa.