Research

Resilience and Tipping Point 

(1) Our perspective paper (Yi et al., 2025) provides a unified framework for studying resilience and tipping points by linking dynamical systems theory with real-world data. We highlight key research directions, including the role of bifurcations, stochasticity, and feedback mechanisms in shaping system stability.

(2) Our review (Yi & Jackson, 2021) synthesizes methods for quantifying ecosystem resilience and discusses their applicability to detecting early warning signals of state transitions.

A threshold precipitation function determines when ecosystem respiration depends on water (Yi et al. 2025)

Terrestrial ecosystem respiration converts organic carbon into CO2 and increases as temperature increases, which causes a positive feedback loop that could accelerate global warming. We identify a threshold precipitation function (Zhang et al., 2025) that determines when ecosystem respiration is temperature-limited or water-limited, helping to reduce uncertainties in climate change projections.

Forest Wind Speed Model

My analytic canopy wind formula (Yi 2008) offers a simple yet effective way to model wind profiles using only LAI, making it widely used in climate, meteorological, and biochemical models. Its efficiency and accuracy have advanced research on canopy turbulence, pollutant dispersion, and atmosphere-forest interactions. 

Mixed-Layer Depth Model

My mixed-layer (ML) height model, known as the YDBB model (Yi, Davis, Berger, and Bakwin, 2001), provides a simple yet effective approach to predicting ML depth using surface sensible heat flux data. Originally developed from long-term observations of boundary layer dynamics, the model has been successfully validated in various studies, demonstrating its robustness in atmospheric research and applications.