Atmospheric river trajectories organise along a global transport network

Abstract. Atmospheric rivers (ARs) transport vast amounts of water vapor and cause weather extremes. However, they have typically been studied as isolated events rather than as components of a global transport system. By mapping ARs worldwide, we reveal that their transport is organized along a sparse set of preferred pathways forming a global network. Recognizing ARs as a globally interconnected system is highly relevant, not only for advancing atmospheric science but also for improving forecasts of extreme precipitation, droughts, and polar ice melt under climate change. Beyond the familiar storm tracks, we identify hubs of pronounced vapor transport changes and demonstrate that polar regions act as structural accumulation regions for persistent ARs. ARs preferentially travel along circumglobal atmospheric highways shaped by teleconnection patterns and circulation regimes, providing new opportunities for AR prediction. While previous research recognized only five AR basins, we uncover a larger, hierarchically organized set of interconnected basins that provides a more comprehensive understanding of how regional AR hotspots are embedded within large-scale flow. The global AR transport network links synoptic storms to planetary circulation, illuminating hidden pathways in the global water cycle.