Investor Presentaiton
Cloudy day
Sunny day
Pressure (hPa)
Pressure (hPa)
Inversion layer height The secondary circulation
in the boundary layer
650
700
(a) 2017-12-12 14
(b) 2017 10 12 14
550
600
650
700
750
800
850
925
1000
925
1000
102°E
104°E
106°E
108°E
102°E
104°E
106°E
108°E
(c) 2017-12-16 14
Boundary layer height
Pressure (hPa)
(d) 2017-12-17 14
550
550
600
600
650
650
700
700
750
750
800
800
850
850
925
925
1000
1000
102°E
104°E
106°E
108°E
102°E
104°E
106°E
177777
Temperature (°C)
-20-18-16-14 -12 -10 -8 -6 -4 -20 2 4 6
8 10 12 14 16 18 20
108°E
was stronger on sunny
days than on cloudy days.
This stronger secondary
circulation increased the
wind shear and turbulent
mixing and provided the
energy required to
10ms increase hmax
Fig. 11. West-east vertical cross-sections of temperature (shading; units: °C) and wind vectors (synthesized
by u and w) through the Sichuan Basin (30.75° N) on sunny days at (a) 14:00 BST on December 12, 2019, (b)
08:00 BST on December 13, 2017 and on cloudy days at (c) 14:00 BST on December 16, 2017 and (d) 14:00
BST on December 17, 2017. The vertical velocity is multiplied by 100 when plotting the wind vectors. The most
polluted area is marked by red dots. The gray shading represents the terrain. The solid line represents the
base of the inversion layer and the red dotted line represents max. This area is not clearly visible.View entire presentation