Mind the Flux: Why Average Accuracy Fails Where the Towers Aren’t
TL;DR for operators Models are often sold as if accuracy were a passport: one clean number, stamped at the border, cleared for deployment. FLUXtrapolation is a useful reminder that the border is usually where the problem begins. The paper introduces a benchmark for predicting hourly ecosystem fluxes — carbon, water, and energy exchanges between ecosystems and the atmosphere — when direct measurements exist only at sparse flux-tower sites.1 The mechanism is simple and unpleasant: train models where towers exist, then test them in progressively less comfortable situations where the future, the geography, or the temperature regime has shifted. ...
