Mishra et al. (2025) An Optimal Transport Framework for Water‐Energy Coupling in Soil‐Vegetation‐Atmosphere Continuum

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Water Resources Research
• Year: 2025
• Date: 2025-12-01
• Authors: Debasish Mishra, Vinit Sehgal, Binayak P. Mohanty
• DOI: 10.1029/2025wr041794

Research Groups

Not explicitly stated in the abstract, but likely Earth system science, hydrology, or climate research groups focused on land-atmosphere interactions and remote sensing.

Short Summary

This study introduces an optimal transport framework based on a least action principle to explain soil moisture-evapotranspiration (SM-ET) coupling across diverse hydroclimates. Global validation using remote sensing data reveals widespread convergence to this least action state, enabling accurate estimation of active root zone depth and characteristic SM transit timescales.

Objective

• To introduce and validate an optimal transport framework, based on the hypothesis that hydroclimates regulate soil moisture-evapotranspiration coupling near a quasi-optimum state characterized by a least action principle.

Study Configuration

• Spatial Scale: Global
• Temporal Scale: Decadal (2010–2019)

Methodology and Data

• Models used: Optimal transport framework based on a least action principle, defined by dynamic convolution between the water potential gradient and the time-weighted mass flux (SM-ET coupling metric).
• Data sources: Decadal (2010–2019) soil moisture (SM) and evapotranspiration (ET) remote sensing data; in situ measurements for root depth validation; isotope measurements for transit time validation.

Main Results

• Global validation revealed widespread convergence toward the least action state across various hydroclimatic zones, supporting the concept of emergent climatic regulation in SM-ET coupling.
• The framework accurately estimated active root zone depth, showing strong correspondence with in situ measurements (correlation > 0.86) across different biomes.
• Dynamic transit times, validated against isotope measurements, suggest that soil moisture perturbations often cycle back into the atmosphere within 3–7 days.

Contributions

• Introduces a novel, physically grounded optimal transport framework for studying water-energy interactions and SM-ET coupling across diverse environments.
• Provides a new method to estimate emergent properties like active root zone depth and characteristic soil moisture transit timescales using remote sensing data.
• Challenges traditional metrics of bulk residence time by demonstrating significantly shorter actual turnover times for soil moisture.

Funding

Not explicitly stated in the abstract.

Citation

@article{Mishra2025Optimal,
  author = {Mishra, Debasish and Sehgal, Vinit and Mohanty, Binayak P.},
  title = {An Optimal Transport Framework for Water‐Energy Coupling in Soil‐Vegetation‐Atmosphere Continuum},
  journal = {Water Resources Research},
  year = {2025},
  doi = {10.1029/2025wr041794},
  url = {https://doi.org/10.1029/2025wr041794}
}