Spatial Distribution and Temporal Trend of Tropospheric NO₂ over the Wanjiang City Belt of China

Figure 12

The cluster of air mass backward trajectories in different seasons in Ma’anshan based on the HYSPLIT model: (a) spring; (b) summer; (c) autumn; (d) winter. The black triangle represents the location of Ma’anshan.

(a)

(b)

(c)

(d)