Identifying the impacts of climate on the regional transport of haze pollution and inter-cities correspondence within the Yangtze River Delta

The above figures clearly show that the variation of PM2.5 concentrations at a city could be Granger cause for the corresponding changes at the other cities. Panel A and B represent the statistically significant correlations during winter time for 2014 and 2015 respectively, and Panel C and D are for summer time.173