Tesfa et al. (2026) Land Surface Heterogeneity Captured by Topography‐Based Subgrid Structures in Grid‐Based and Watershed‐Based Computational Units

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

Identification

• Journal: Journal of Advances in Modeling Earth Systems
• Year: 2026
• Date: 2026-01-01
• Authors: T. K. Tesfa, L. Ruby Leung, Zhuoran Duan
• DOI: 10.1029/2025ms005101

Research Groups

Not explicitly mentioned in the abstract.

Short Summary

This study evaluates the effectiveness of topography-based subgrid units (TGUs) derived from grid- versus watershed-based computational units (CUs) in capturing surface heterogeneity for Earth System Models (ESMs). It finds that watershed-based TGUs are superior to grid-based TGUs in representing spatial heterogeneity of topographic slope, land cover, and surface hydrometeorology across various spatial scales, leading to improved accuracy in hydrometeorological simulations.

Objective

• To evaluate the capability of topography-based subgrid units (TGUs), derived from both grid-based and watershed-based computational units (CUs), to capture small-scale surface heterogeneity relevant for Earth System Models (ESMs).

Study Configuration

• Spatial Scale:
  • Grid-based CUs: 1°, 0.5°, 0.25°, and 0.125°
  • Watershed-based CUs: Hydrologic Unit Code levels HUC07, HUC08, HUC09, and HUC10
  • Domain: Continental United States (CONUS)
• Temporal Scale: Not explicitly mentioned in the abstract for the evaluation period.

Methodology and Data

• Models used: Algorithms for subgrid topographic unit (TGU) discretization within Earth System Model (ESM) computational units (CUs) were introduced and evaluated.
• Data sources:
  • Observed precipitation, temperature, and snow water equivalent from SNOwpack TELemetry (SNOTEL) sites.
  • Implied data for topographic elevation, topographic slope, land cover, and surface hydrometeorology for statistical metric computation.

Main Results

• Watershed-based TGUs are superior to grid-based TGUs in capturing spatial heterogeneity related to topographic slope, land cover, and surface hydrometeorology.
• Both grid-based and watershed-based TGUs showed similar capabilities in capturing topographic elevation.
• The improved capability of watershed-based TGUs, resulting from combined CU and TGU level discretization, was consistent across all examined spatial scales.
• At the finest spatial scales (0.125° and HUC10), watershed-based TGUs better captured observed precipitation, temperature, and snow water equivalent than grid-based TGUs at 94%, 84%, and 72% of SNOTEL sites, respectively.

Contributions

• Introduces and evaluates new algorithms for discretizing ESM computational units into topography-based subgrid units to improve the representation of small-scale surface heterogeneity.
• Demonstrates the significant advantage of watershed-based subgrid units over traditional grid-based units for capturing complex surface properties and hydrometeorological variables.
• Provides a pathway for enhancing the accuracy and realism of Earth System Model simulations with minimal computational demand increase.

Funding

Not explicitly mentioned in the abstract.

Citation

@article{Tesfa2026Land,
  author = {Tesfa, T. K. and Leung, L. Ruby and Duan, Zhuoran},
  title = {Land Surface Heterogeneity Captured by Topography‐Based Subgrid Structures in Grid‐Based and Watershed‐Based Computational Units},
  journal = {Journal of Advances in Modeling Earth Systems},
  year = {2026},
  doi = {10.1029/2025ms005101},
  url = {https://doi.org/10.1029/2025ms005101}
}