Quasi-weekly oscillation of regional PM2.5 transport over China driven by the synoptic-scale disturbance of East Asian Winter Monsoon circulation

Abstract. The regional PM_2.5 transport is one of the important causes for atmospheric environment change. However, the variations of regional PM_2.5 transport in synoptic scale with meteorological drivers have been incomprehensively understood. Therefore, this study is targeted at the quasi-weekly oscillation (QWO) of regional PM_2.5 transport over central and eastern China (CEC) with the influence of synoptic-scale disturbance of the East Asian Winter Monsoon (EAWM) circulation. By constructing the data of daily PM_2.5 transport flux in CEC in the winters of 2015–2019, we utilize the extended empirical orthogonal function (EEOF) decomposition and other statistical methods to extract the moving spatial distribution of regional PM_2.5 transport over CEC, recognizing the QWO in regional PM_2.5 transport with the spatial-temporal variations over CEC. The source-acceptor relationship in regional transport of PM_2.5 is identified with the 2-d lag effect of the North China Plain, as the upwind source region, on the PM_2.5 pollution change in the Twain-Hu Basin, as the downwind receptor region in central China. The QWO of regional PM_2.5 transport over CEC is regulated by the synoptic-scale disturbance of the EAWM circulation with the periodic activities of Siberian high. These findings could provide new insight into the understanding of regional PM_2.5 transport with source-receptor relationship and the meteorological mechanism in atmospheric environment change.