We developed EcoTWIN v1.0, a new fully distributed tracer-aided ecohydrological model that tracks water, isotopes, and nutrients fluxes. The model was successfully tested in 17 large European catchments across diverse geological and climatic backgrounds. As a tracer-aided model, EcoTWIN not only captures flow paths but also estimates water ages/travel times, thus bridging hydrology with water quality. This opens new possibilities for understanding the synergy between water and nitrogen cycles.

The Singular Value Decomposition-three Dimensional Ensemble Variational data assimilation scheme is applied for the first time in the Tropical Regional Atmospheric Model System. With optimized three-dimensional perturbation generation and parallel strategies, computational costs were greatly reduced. Results indicate that the optimized scheme maintains reasonable accuracy while achieving much higher efficiency, suggesting good potential for practical forecasting use.