A Community Perspective on Hydrologic Science Opportunities for Earth Observations

<jats:p>Existing satellite systems primarily observe individual components of the terrestrial water cycle, whereas drought is fundamentally an emergent, temporary process resulting from interactions among all terrestrial water storage compartments and human water use (AghaKouchak et al., 2015; AghaKouchak et al., 2021). Given the complex nature of monitoring drought across several temporal and spatial domains, remote sensing tools enable us to augment our limited in situ networks while also helping us to better detect rapid onset/intensification of drought. This technology frontier is ripe for flash drought detection and mapping (Otkin et al., 2018; Christian et al., 2024). These tools can also help us better support agricultural, environmental and water resource management and decision making. As such, to better understand and advance drought monitoring and mitigation, we recommend prioritizing measurements focused on multi-domain compartment water storage, subsurface moisture, human water use quantification and coupled water-energy budgets. This white paper is an outcome of a community-led, community-engaged effort to identify and elevate emerging opportunities in hydrologic science that can provide significant benefits for decision-making related to drought, floods, water quality, water supply and water demand.</jats:p>