Luo et al. (2026) The role of soil moisture on summer atmospheric circulation climatology in the Northern Hemisphere

Identification

• Journal: npj Climate and Atmospheric Science
• Year: 2026
• Authors: Fei Luo, Frank Selten, Coumou Dim
• DOI: 10.1038/s41612-025-01294-4

Research Groups

• Institute for Environmental Studies, Vrije Universiteit Amsterdam, the Netherlands.
• Royal Netherlands Meteorological Institute (KNMI), De Bilt, the Netherlands.
• Centre for Climate Research Singapore (CCRS), Meteorological Service Singapore (MSS), Singapore.

Short Summary

This study demonstrates that interactive soil moisture significantly alters Northern Hemisphere summer circulation by shifting subtropical jets poleward and amplifying planetary wave amplitudes over land. The findings reveal that soil moisture-atmosphere feedbacks are a primary driver of both mean atmospheric state and temperature extremes.

Objective

• To quantify the influence of interactive soil moisture on large-scale atmospheric circulation climatology and land-atmosphere coupling during the Northern Hemisphere summer.

Study Configuration

• Spatial Scale: Northern Hemisphere (extratropical and mid-latitude regions).
• Temporal Scale: Boreal summer climatology (June, July, August).

Methodology and Data

• Models used: EC-Earth 3 (state-of-the-art Earth System Model) using large-ensemble simulations.
• Data sources: ERA-Interim/Land reanalysis data (for soil moisture states) and the Hurrell sea surface temperature (SST) and sea ice boundary dataset.
• Experimental Design: Comparison between a fully interactive soil moisture simulation and a control experiment with prescribed soil moisture states.

Main Results

• Circulation Shifts: Interactive soil moisture drives a distinct poleward displacement of the subtropical jets and strengthens the polar front jet.
• Wave Amplification: Land-atmosphere coupling is enhanced, leading to an amplification of planetary wave amplitudes over land by approximately 24%.
• Thermal Impact: Interactive soil moisture increases mean summer surface temperatures by up to +1.5 K.
• Extreme Events: The feedback mechanisms amplify temperature extremes by up to +3.0 K.

Contributions

• Provides quantitative evidence that soil moisture fluctuations are not merely local phenomena but can modify the mean global atmospheric circulation.
• Identifies a significant bias in climate projections that may occur if soil moisture-atmosphere feedbacks are not fully coupled.
• Enhances the understanding of the dynamical drivers behind persistent summer weather extremes.

Funding

• Netherlands Organization for Scientific Research (NWO) VIDI award (Project PERSIST: Persistent Summer Extremes, grant 016.Vidi.171.011).

Citation

@article{Luo2026role,
  author = {Luo, Fei and Selten, Frank and Dim, Coumou},
  title = {The role of soil moisture on summer atmospheric circulation climatology in the Northern Hemisphere},
  journal = {npj Climate and Atmospheric Science},
  year = {2026},
  doi = {10.1038/s41612-025-01294-4},
  url = {https://doi.org/10.1038/s41612-025-01294-4}
}

Generated by BiblioAssistant using gemini-3-flash-preview (Google API)