Zhang et al. (2026) Springtime Soil Moisture Teleconnections Drive Summertime Warming in the Western United States

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

Identification

• Journal: Journal of Climate
• Year: 2026
• Date: 2026-09-22
• Authors: Lily N. Zhang, David S. Battisti, Lucas R. Vargas Zeppetello, Marysa M. Laguë
• DOI: 10.1175/jcli-d-25-0459.1

Research Groups

Not explicitly stated in the provided abstract.

Short Summary

This study uses an ensemble of soil moisture depletion experiments within CESM2 to demonstrate that reduced March surface soil moisture in the Southwest US causes positive May-June temperature anomalies across the Western US and precipitation anomalies in the Northwest, consistent with observations. It identifies land-atmosphere coupling and subsequent hemispheric-scale circulation changes as the mechanism for this seasonal teleconnection.

Objective

• To investigate and demonstrate, through model experiments, that regional variations in springtime soil moisture over the American Southwest cause distal summertime temperature and precipitation anomalies across the Western United States.

Study Configuration

• Spatial Scale: American Southwest, Western United States, Northwest, hemispheric-scale.
• Temporal Scale: Springtime, summertime, March, May–June, early spring, late spring and early summer, seasonal time scales.

Methodology and Data

• Models used: Community Earth System Model (CESM2)
• Data sources: Ensemble of soil moisture depletion experiments (model-based), compared with observations.

Main Results

• A reduction in March surface soil moisture over the Southwest US causes positive May–June temperature anomalies throughout the Western US.
• The same reduction in March soil moisture causes precipitation anomalies in the Northwest.
• These modeled temperature and precipitation anomalies are consistent with observations.
• Daytime diabatic heating over anomalously dry land surfaces in early spring excites circulation anomalies.
• These circulation anomalies evolve into a hemispheric-scale pattern similar to that observed following anomalously dry springtime in the Southwest US.
• Subsequent late spring and early summer circulation anomalies are associated with large-scale reductions in atmospheric moisture and cloudiness.
• These reductions in atmospheric moisture and cloudiness contribute to the near-surface warming.

Contributions

• Provides experimental evidence, using a state-of-the-art Earth System Model, for a causal link between springtime soil moisture variations in the American Southwest and subsequent summertime climate anomalies across the Western US.
• Elucidates the physical pathway for this teleconnection, involving land-atmosphere coupling, diabatic heating, and the excitation of hemispheric-scale circulation anomalies.
• Highlights the potential for soil moisture variations to serve as a source of predictability on seasonal time scales in the Western US.

Funding

Not explicitly stated in the provided abstract.

Citation

@article{Zhang2026Springtime,
  author = {Zhang, Lily N. and Battisti, David S. and Zeppetello, Lucas R. Vargas and Laguë, Marysa M.},
  title = {Springtime Soil Moisture Teleconnections Drive Summertime Warming in the Western United States},
  journal = {Journal of Climate},
  year = {2026},
  doi = {10.1175/jcli-d-25-0459.1},
  url = {https://doi.org/10.1175/jcli-d-25-0459.1}
}