Northward shift of transboundary air pollution pathways over the western Pacific under climate change

Climate change influences weather patterns induced by large-scale circulation, leading to changes in wind and precipitation. Consequently, aerosol transport patterns are thought to be shifted, thereby influencing the movement of air pollutants through environment-climate interactions. However, the long-term trends and mechanisms driving the shifts in transboundary air pollution pathways remain unclear, particularly in the downwind region around East Asia. Here, we investigated recent decadal trends in transboundary air pollution pathways by applying RAOD , a new metric that quantifies the long-term variations in these pathways. By combining reanalysis and satellite products, we demonstrated how the decadal trends of RAOD characterize the shortening of the eastward aerosol transport distance. Our analyses revealed that although the aerosol composition exerts a minor influence on transport, changes in precipitation and circulation, even near source regions, have played a major role in aerosol climatology. This emphasizes that climate-driven circulation shifts may redefine global pollution transport.