Coupling detrended fluctuation analysis of the relationship between PM2.5 concentration and weather elements

PM2.5 pollution in China is getting worse. The relationship between PM2.5 concentration and weather elements exhibits complex non-linear feature. Therefore, it is very important to study the sophisticated mathematical and nonlinear method about the relationship between PM2.5 concentration and weather elements. Coupling detrended fluctuation analysis (CDFA) method can reveal the multifractal properties of more than two series. The coupled correlations between PM2.5 concentration and weather elements in Hangzhou and Guangzhou are explored by CDFA. We find that coupled correlations are not only multifractal but also anti-persistent. Compared with Guangzhou, Hangzhou has stronger correlations. Both long-range correlation and fat-tailed distribution can cause the coupled multifractality. and the long-range correlation has a greater influence on the coupled multifractality. In addition, the coupling sensitivity degree (CSD(Y)) is used to study which weather element plays a key role in the change of PM2.5 concentration. •The coupling correlations between PM2.5 concentration and weather elements are discussed by CDFA and CSD.•The coupling correlations between PM2.5 concentration and weather elements are multifractal and anti-persistent.•The coupling multifractality is caused not only by long-range correlation but also by fat-tailed distribution.•The coupling sensitivity degree (CSD(Y)) is used to explore which weather element plays a key role (more sensitive) in the change of PM2.5 concentration.