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

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 PM 2.5 and meteorology, we investigated the modulation of AR and TP's anomalous warming on the variations of PM 2.5 pollution and regional transport over central and eastern China (CEC), including major PM 2.5 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 PM 2.5 pollution in different ways respectively with prominently influencing the interannual changes of PM 2.5 concentrations and heavy PM 2.5 pollution occurrences. The impacts of anomalous warming in TP and AR on PM 2.5 pollution consistently enhanced regional PM 2.5 transport from NC to YRD and SC, while the warming anomalies over AR and TP respectively enhanced and inhibited the southward transport of PM 2.5 from NC. In association with the synergistic impact of warming anomalies in AR and TP, the regional PM 2.5 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 PM 2.5 anomalies in NC and CC and positive PM 2.5 anomalies in YRD and SC. Our results highlight the effect of warming anomalies in AR and TP on the PM 2.5 pollution over China with the implication of source–receptor relationship of regional transport of air pollutants. • The climate changes of AR and TP prominently alter the PM 2.5 concentrations and heavy pollution occurrences in CEC. • The warming anomalies over AR and TP respectively enhance and inhibit the southward transport of PM 2.5 in the CEC. • The synergistic effect of anomalous warming in AR and TP induces an inverse anomaly of PM 2.5 transport pattern over CEC. [ABSTRACT FROM AUTHOR]