Mountainous critical zones (CZs) regulate water, solute, and energy fluxes that sustain downstream ecosystems and water resources. Yet predictive understanding of coupled hydro-bio-geochemical processes remains limited in these systems, largely due to the scarcity of high-resolution, long-term observations of fluxes, tracers, water chemistry, and mineral weathering.

This session invites process-based and hypothesis-driven studies that advance understanding of mountainous CZs through integrated observations, experiments, and modeling. We seek studies addressing key challenges: (i) what governs the spatiotemporal organization of flow paths, and how can these be represented in models? (ii) how do climate-driven shifts in precipitation phase and intensity as well as vegetation dynamics affect soil moisture dynamics and groundwater recharge? (iii) how can groundwater circulation depths and residence times be robustly constrained? and (iv) how do disturbances such as wildfire and extreme events reshape ecohydrological processes, water quantity/quality?

We welcome interdisciplinary contributions spanning hydrology, soil science, geochemistry, and numerical modeling.

• B - Biogeosciences
• C - Cryosphere
• GC - Global Environmental Change
• V - Volcanology, Geochemistry and Petrology