PIK develops a new global, high resolution data set of atmospheric rivers

Atmospheric rivers are narrow bands of moisture in the lower atmosphere, which act as conveyer belts of water vapour around the Earth. They typically carry more than twice the flow of the Amazon River, acting as a vital source of freshwater, and triggers for extreme rainfall and winds. Beyond water, atmospheric rivers also transport heat around the Earth, and influence snow accumulation and ice melt in the polar regions.

To date, identifying and mapping atmospheric rivers has largely been confined to individual regions. Accurate global data sets are difficult to develop, as detection in the tropics and the polar regions is complicated by their moisture content and atmospheric dynamics. This has led to both over and under detection in certain regions.

The PIK team built upon previous methodologies to develop a new atmospheric river detection tool and catalogue that improves identification and tracking. PIKART is able to differentiate atmospheric rivers from other weather systems and account for the increase in atmospheric moisture content from global heating. It advances detection in the polar and tropical regions, and enhances the representation of intense and long-lived atmospheric river trajectories at global scale. In addition, it also identifies inland penetration hotspots for the first time, which have important social, ecological and economic implications for hydrological extremes and freshwater supply beyond coastal regions.

Overall, this information is crucial both for ongoing research, and forecasting and resource management. It is designed to be used by scientists, meteorologists, water resource managers, as well as experts working in risk management and adaptation planning. It’s anticipated that PIKART will open the door to novel areas of research, such as atmospheric river generation over land areas.