Kim et al. (2026) Interseasonal Hysteresis and Linearity Among Surface Energy Fluxes and Soil Water Content in Observations, Reanalyses, and Model Simulations

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

Identification

• Journal: Geophysical Research Letters
• Year: 2026
• Date: 2026-07-22
• Authors: Sungyoon Kim, Paul Alan Dirmeyer, Eunkyo Seo, Daisuke Tokuda, Megan D. Fowler
• DOI: 10.1029/2026gl121975

Research Groups

• Department of Earth Sciences, University of California, Berkeley
• National Center for Atmospheric Research (NCAR)
• NASA Goddard Space Flight Center

Short Summary

This study examines the representation of surface energy partitioning dynamics with soil water content across CONUS using in situ observations and model-derived products. Large discrepancies emerge in the representation of SWC-EF dynamics, highlighting the need to improve land-atmosphere coupling parameterizations.

Objective

• Investigate the variations in surface energy budget components (latent heat flux, sensible heat flux, and net radiation) with soil water content across CONUS

Study Configuration

• Spatial Scale: Continental United States (CONUS)
• Temporal Scale: Monthly variations over a full annual cycle

Methodology and Data

• Models used:
  • MERRA2 reanalysis
  • ERA5 reanalysis
  • CESM offline configuration with CLM model
  • CESM coupled configuration with CLM+CAM models
• Data sources:
  • In situ observations (OBS)
  • Model-derived products

Main Results

• Large discrepancies emerge in the representation of SWC-EF dynamics during the growing season.
• ERA5 reproduces EF magnitude but produces the opposite interseasonal hysteresis of SWC-EF than OBS.
• CLM captures the observed SWC-LE/SH/EF relationships better than CLM+CAM, suggesting biases introduced by coupled LA processes.

Contributions

• This study highlights the need to improve land-atmosphere coupling parameterizations for more accurate and hysteresis-aware model behavior.

Funding

• NASA's Terrestrial Hydrology Program (NNX14AP49G)
• National Science Foundation's Division of Earth Sciences (EAR-1520770)

Citation

@article{Kim2026Interseasonal,
  author = {Kim, Sungyoon and Dirmeyer, Paul Alan and Seo, Eunkyo and Tokuda, Daisuke and Fowler, Megan D.},
  title = {Interseasonal Hysteresis and Linearity Among Surface Energy Fluxes and Soil Water Content in Observations, Reanalyses, and Model Simulations},
  journal = {Geophysical Research Letters},
  year = {2026},
  doi = {10.1029/2026gl121975},
  url = {https://doi.org/10.1029/2026gl121975}
}