Fig. 3. Scatterplots and spatial distributions of the model simulations with observations overlaid for mean planetary boundary layer height (PBLH) at 8:00 and 20:00 LT over China during the pollution episodes from ((a)–(f)) 11 to 19 January and from ((g)–(l)) 28 May to 15 June 2018. The middle column refers to Nudging case, and the right column refers to Base case.