Fig. 1
Two nested model domain for NAQPMS used in this study. Also shown are regional separations for on-line tracer-tagged (capital characters) which are described in Table 1. The marked solid squares represent the locations of nine observation stations.
Table 1
Tagged aerosol production regions in East Asiaa
[i] aRegion locations are shown in Fig. 1.
Fig. 2
Time profile of the model simulated (black) and observed (red) hourly and daily PM10 (or PM2.5) during 25 March–7 April 2011 at Shanghai, Hongze Lake, Changdao, Xinglong, Yanjiao, Dalian and Anshan. Two high polluted cases (Case I and II) and one clear case (Case III) are marked by the semi-transparent shaded.
Table 2
Statistical summary of comparisons of simulated particulate matter with observationsa
[i] aN is the number of samples. , , r, MB, RMSE, NMB and NME represent the mean modeled and observed values, correlation coefficient, mean bias, root mean square error, normalised mean bias and normalised mean error. Units are µg/m3. Observations at Shanghai, Hongze Lake, Changdao, Xinglong and Yanjiao are hourly mean PM2.5. Values for Dalian and Anshan are daily mean PM10 derived from Chinese API.
Fig. 3
Time series of contributions (µg/m3) to surface PM10 at Anshan, Dalian and Yanjiao, and PM25 at Xinglong, Changdao, Hongze Lake and Shanghai from selected city clusters.
Fig. 4
Simulated spatial distributions of mean near-ground (<1.5 km) PM2.5 (µg/m3) and wind vectors (m/s, arrows) during a) Case I, b) Case II and c) Case III. Also shown are the transport fluxes of PM2.5 (µg/m2/s) during d) Case I, e) Case II and f) Case III. Locations of Anshan, Xinglong, Changdao and Hongze Lake are marked by the dark solid cycles.
Fig. 5
Spatial distributions of contributions (shaded, µg/m3) to mean near-ground (<1.5 km) PM2.5 from a) YRD; b) SD + OCEAN and c) HBP in Case I. Also shown are the transport fluxes of these contributions d) YRD; e) SD + OCEAN and f) HBP. The thick black lines in d), e), and f) represents the transport pathways, and the capital letters ‘A’, ‘B’ and ‘C’ means the key points along the pathways. Locations of Anshan, Xinglong, Changdao and Hongze Lake are marked by the dark solid cycles.
Fig. 6
Vertical profiles of contributions (µg/m3) of regional transport from a) YRD; b) SD+OCEAN and c) HBP to PM2.5 along the transport pathway in Case I (shown in Fig. 5). The capital letters ‘A’, ‘B’ and ‘C’ represent the locations of key points along the pathways shown in Fig. 5.
Fig. 7
Locations and height (meter, colors) above ground of 3-day back-trajectories initiated from at Anshan, Xinglong, Changdao and Hongze Lake at 100 m above ground level for the period (a) Case I, (b) II and (c) III. Two successive points represents a three hour interval. The four city clusters (CL, HBP, SD and YRD) are as explained in Fig. 1.
Fig. 8
Sea level pressure (hpa) (black contours) and wind vectors (m/s) (red arrows) during a) Case I; b) Case II and c) Case III. Also shown are locations of Anshan, Xinglong, Changdao and Hongze Lake stations. The character ‘H’ and ‘L’ represent the center of high pressure and low pressure systems, respectively.
Fig. 9
The same as Fig. 5, but for Case II.
Fig. 10
The same as Fig. 6, but for Case II.
Fig. 11
The same as Fig. 5, but for Case III.