Atmospheric moisture transport may be a key driver behind increased precipitation and an enhanced hydrological cycle trend in northern high latitudes in coming years, reports a study published online in Nature Climate Change this week. Previously these trends-which are indicated by increasing Eurasian Arctic river discharges and climate model projections-had been attributed to various factors as a result of local warming effects.

Xiangdong Zhang and colleagues find that the increase in river discharge has accelerated over the past decade, and that enhancement of poleward atmospheric moisture transport decisively contributes to this increase.

This knowledge will help understanding of hydrological interactions with climate systems, such as the contribution of water vapour to polar amplification, as well as implications for density-driven ocean circulation.