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853405.fig.003b
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853405.fig.003c
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Figure 3: Zoom-in on typical wind circulation patterns at breathing level associated with high and low PM2.5 concentrations in the nonattainment area in October to March. The contour lines represent the potential temperature gradient (K.100 m−1) between the surface and 150 m above the ground; the red polygon indicates the nonattainment area. The community of North Pole is located in the lower right region of the nonattainment area.