Fig. 1From: Correlation networks of air particulate matter (\(\hbox {PM}_{2.5}\)): a comparative studyData Description. a, c Probability density functions of \(\hbox {PM}_{2.5}\) concentrations across seasons. b, d Spatial distribution of average \(\hbox {PM}_{2.5}\) concentrations from Jan. 2014 to May 2020 respectively for China and CaliforniaBack to article page