Identifying the impacts of warming anomalies in the Arctic region and the Tibetan Plateau on PM2.5 pollution and regional transport over China

Abstract

Arctic region (AR) and Tibetan plateau (TP) are the most sensitive regions to climate change and have synchronously experienced accelerated warming over recent decades. Based on the multi-year observational data of PM2.5 and meteorology, we investigated the modulation of AR and TP's anomalous warming on the variations of PM2.5 pollution and regional transport over central and eastern China (CEC), including major PM2.5 pollution regions in northern China (NC), the Yangtze river delta (YRD), central China (CC), and southern China (SC). Results show that the thermal effects of TP and AR modulated PM2.5 pollution in different ways respectively with prominently influencing the interannual changes of PM2.5 concentrations and heavy PM2.5 pollution occurrences. The impacts of anomalous warming in TP and AR on PM2.5 pollution consistently enhanced regional PM2.5 transport from NC to YRD and SC, while the warming anomalies over AR and TP respectively enhanced and inhibited the southward transport of PM2.5 from NC. In association with the synergistic impact of warming anomalies in AR and TP, the regional PM2.5 transport over CEC presented the inverse patterns of the northward anomalies between NC and CC and the southward anomalies from the eastern part of NC, YRD to SC, forming the regional distribution with negative PM2.5 anomalies in NC and CC and positive PM2.5 anomalies in YRD and SC. Our results highlight the effect of warming anomalies in AR and TP on the PM2.5 pollution over China with the implication of source–receptor relationship of regional transport of air pollutants.