My research focuses on using coupled numerical models to study the interaction among subsurface, land surface, ecosystem, and the atmosphere. The forest ecosystem model, Biome-BGC, is being coupled with a physically-based land surface hydrologic model, Flux-PIHM. Because the Penn State Integrated Hydrologic Model (PIHM) is capable of simulating lateral groundwater flow that explicitly resolves low-order channel networks, the coupled model, Flux-PIHM-BGC will be able to represent the land surface and ecosystem heterogeneities caused by topography. The modeling system will be implemented at the Shale Hills Critical Zone Observatory. The broad array of water cycle, energy cycle, and carbon cycle observations enables the investigation of subsurface-land surface-ecosystem interaction. The measured and simulated temporal variation in the dynamic below-ground C processes, including root production, mortality and soil respiration, will be evaluated in relation to variation in soil moisture, temperature, and above-ground phenology, to investigate the impact of topography in belowground C processes.
Shi, Y., K. J. Davis, C. J. Duffy, and X. Yu, 2013: Development of a coupled land surface hydrologic model and evaluation at a critical zone observatory. Journal of Hydrometeorology, 14, 1401—1420, doi:10.1175/JHM-D-12-0145.1.