Bryn Stewart

Bryn Stewart is a Foster and Coco Stanback Postdoctoral Scholar Research Fellow in Environmental Science and Engineering at the California Institute of Technology (Caltech), affiliated with the Division of Geological and Planetary Sciences. His research focuses on catchment hydrology, biogeochemical cycles, and critical zone processes, with an emphasis on understanding how subsurface dynamics, climate, and geology influence carbon and nutrient export in watersheds. Stewart's work integrates field observations, reactive transport modeling, and interdisciplinary collaborations to address questions about ecosystem resilience and carbon cycling.

Key research interests include subsurface water flow pathways, dissolved organic and inorganic carbon dynamics, and the role of deep subsurface respiration in global carbon budgets. He has conducted extensive studies at the Sleepers River Research Watershed in Vermont, exploring long-term hydrological and biogeochemical responses to disturbances such as climate change and land-use alterations. His contributions include developing models like BioRT-HBV to simulate watershed-scale biogeochemical processes.

Stewart’s publications highlight advancements in understanding solute export patterns across the contiguous U.S., the influence of geology on river chemistry, and the interplay between snowmelt, soil moisture, and streamflow dynamics. His research bridges hydrology, ecology, and geochemistry, emphasizing data-driven approaches and collaborative frameworks to advance critical zone science.