Stable isotope ratios of hydrogen and oxygen in water serve as a cornerstone for investigating the behavior of climate across past, present, and future timescales. Stable isotopes in water have been used to reconstruct climate variability, trace moisture sources and sinks, and diagnose physical processes operating within the atmosphere, ocean, land surface, cryosphere, and biosphere. Recent progress has expanded the scope of isotope-enabled research. High-frequency and spatially extensive observational techniques, spanning both in-situ and satellite platforms, are now complemented by advances in numerical modeling frameworks and the growing integration of machine learning approaches for pattern extraction, data assimilation, and predictive modeling. Improved theoretical understanding of isotopic fractionation and transport strengthens signal interpretation. This session invites studies that leverage observations, modeling, and data-driven methods, including machine learning, to advance hydroclimate understanding. Topics of interest include mean-state dynamics and extreme events, across temporal scales from paleoclimate reconstructions to future projections.

• A - Atmospheric Sciences
• C - Cryosphere
• GC - Global Environmental Change
• H - Hydrology