This session highlights water cycle research that emphasizes the Earth as a connected system, describing linkages between the ocean, atmosphere, and land surface and subsurface processes. Contributions are invited on all aspects of water cycle research, including analyses undertaken using in situ and spaceborne observations from current (e.g., GO-SHIP, Argo, SMAP, SMOS, GRACE-FO, GPM, GCOM-W), past (e.g., Aquarius, TRMM, GRACE), and future (e.g., CIMR) satellite missions, estimates based on numerical models, data assimilation products, as well as climate model projections and theoretical contributions. We particularly welcome studies that consider multiple realms (the ocean, atmosphere, land surface, and subsurface) and provide compelling evidence for linkages, describing coherent water cycle variability and change. We welcome global and regional assessments across these interfaces and contributions that demonstrate what needs to be observed to ensure that long-term changes in the water cycle are accurately quantified. Abstracts related to the SWOT mission are strongly encouraged as the first global all surface water mission is scheduled for launch later this year.