A robust representation of terrestrial carbon, energy, and water cycles requires a fundamental understanding of biosphere-atmosphere interactions, particularly in the context of a rapidly changing climate. However, a significant challenge arises from the mismatch that occurs when carbon, water, or energy fluxes are measured or modelled at different spatio-temporal scales. Multiple processes determine how mass and energy exchanges scale from the leaf, to the whole plant, to the ecosystem, and eventually to the globe. Despite the evolution of Earth system models to incorporate increasingly complex processes across these scales, uncertainties persist due to these mismatches. The unprecedented rate of climate change, along with the increasing frequency and intensity of extreme events, further complicates our ability to robustly formulate mechanistic underpinnings of biogeochemical processes across scales.
The increasing volume of data at multiple scales—from leaf-level measurements (e.g., gas exchange), tree-level measurements (e.g., sap flow and dendroecology), ecosystem-level measurements (e.g., eddy covariance towers, UAVs, aircraft), to Earth observation from space—presents new opportunities to address these challenges. This session invites studies that improve our overall understanding of biosphere-atmosphere interactions by addressing the mismatches across different temporal and spatial scales and integrating these insights into modeling strategies. We particularly encourage contributions that explore the effects of climate extremes (e.g., drought, heatwaves, excess rainfall, winter warming) on carbon, energy, and water fluxes. In addition to empirical multi-scale observations, we welcome research that delves into data-driven diagnostics and constraints for model evaluation, data-driven parameterisations in mechanistic models, and the development of data-driven/hybrid modelling strategies (i.e., seamless fusion of data-driven approaches and mechanistic models) for an integrated understanding of carbon, energy, and water fluxes across scales.