Lianyu Yu, PhD

Northwest A&F University,

Recent climate changes have accelerated the coupled water, heat, and carbon exchanges in cold regions, which can further exert the positive feedbacks to climate changes, leading to the increasingly vulnerable ecosystem, warming climate, and unsustainable Earth system. The current ESMs, however, usually adopted the single-phase flow physics with the omission of soil vapor flow and dry airflow. This results in the model discrepancies and may lead to large uncertainties in the future projection of Earth system under climate changes. With such knowledge gaps in mind, this talk is aiming to understand the underlying physics of water, heat, and carbon exchange processes and links it to the surface/subsurface hydrothermal, biogeochemical, ecohydrological regimes. Two questions will be proposed and elaborated in this presentation, i.e., i) how does different vadose zone physics affect our interpretation of soil hydrothermal regimes? ii) Furthermore, how does such difference affect ecosystem functioning (carbon status)?