🤖 AI Summary
This study addresses the challenges posed by sparse and regionally biased ground-based carbon flux observations, which severely limit the generalization and increase the uncertainty of data-driven upscaling methods. To overcome these limitations, we propose a novel framework that integrates physical constraints with adaptive representation learning. Specifically, we develop a knowledge-guided encoder–decoder architecture grounded in the carbon balance equation, augmented with spatiotemporal representation learning and a task-aware modulation mechanism to enable high-accuracy upscaling of terrestrial carbon fluxes. Our approach represents the first successful integration of physical priors with deep representation learning, substantially enhancing model robustness and cross-regional transferability. Experiments across more than 150 flux tower sites demonstrate consistent improvements, with RMSE reduced by 8–9.6% and R² increasing from 19.4% to 43.8%.
📝 Abstract
Accurately upscaling terrestrial carbon fluxes is central to estimating the global carbon budget, yet remains challenging due to the sparse and regionally biased distribution of ground measurements. Existing data-driven upscaling products often fail to generalize beyond observed domains, leading to systematic regional biases and high predictive uncertainty. We introduce Task-Aware Modulation with Representation Learning (TAM-RL), a framework that couples spatio-temporal representation learning with knowledge-guided encoder-decoder architecture and loss function derived from the carbon balance equation. Across 150+ flux tower sites representing diverse biomes and climate regimes, TAM-RL improves predictive performance relative to existing state-of-the-art datasets, reducing RMSE by 8-9.6% and increasing explained variance ($R^2$) from 19.4% to 43.8%, depending on the target flux. These results demonstrate that integrating physically grounded constraints with adaptive representation learning can substantially enhance the robustness and transferability of global carbon flux estimates.