Research on changes in the pace of the water cycle dates back to the 1970s. In the last few decades, leveraging a number of new regional and global datasets, research has highlighted changes in the water cycle attributed to secular trends in relevant processes and/or to anthropogenic activities. For example, studies have investigated changes in the rate of exchange across terrestrial water storages and each of their components (soil moisture, snow, surface and groundwater, etc.) using different datasets, including remotely sensed, modeled, or data-assimilated, and reanalysis products. Past studies have also differed in their period of analysis, regional focus, and methods for change analysis and attribution.
This session aims to provide a platform to present and discuss studies that seek to understand (i) the current state of knowledge on accelerating or decelerating water cycle processes and (ii) uncertainties and open questions related to this critically important research topic. Studies focused on change analysis of individual or integrated water cycle components using one or more of the above-mentioned data types are encouraged, with either a regional or global focus. We are particularly interested in studies that highlight existing uncertainties in the state of knowledge regarding the magnitude or direction of these changes. Studies that lead to the development of new datasets to facilitate water cycle change analysis are also welcome, including studies focused specifically on the attribution of changes in the pace of the water cycle.