Chen et al. (2025) The Impact of Large‐Scale Land Surface Conditions on the South American Low‐Level Jet

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

Identification

• Journal: Geophysical Research Letters
• Year: 2025
• Date: 2025-12-28
• Authors: Chu‐Chun Chen, Francina Domínguez, Sean Matus
• DOI: 10.1029/2025gl116905

Research Groups

Not specified in abstract.

Short Summary

This study investigates the influence of antecedent soil moisture on the dynamics of the South American low-level jet (SALLJ), specifically strong Chaco jets, finding that dry soil conditions significantly intensify these jets by enhancing land-atmosphere interactions.

Objective

• To examine the role of antecedent soil moisture in modulating the dynamics of the South American low-level jet (SALLJ), particularly strong Chaco jets, focusing on land-atmosphere interactions rather than solely atmospheric controls.

Study Configuration

• Spatial Scale: Southeastern South America, specifically northern Argentina (Chaco region).
• Temporal Scale: Event-based analysis of Chaco jet events, focusing on antecedent soil moisture conditions up to 5 days before the jet's peak.

Methodology and Data

• Models used: Implied by reanalysis data, but not specified.
• Data sources: Reanalysis data.

Main Results

• 54 strong Chaco jet events were identified.
• 63% of these events occurred under drier-than-normal antecedent soil moisture conditions over northern Argentina.
• Dry soils are associated with enhanced surface sensible heating, lower-tropospheric warming, and a deepened thermal low.
• These conditions lead to an intensification of the Chaco jet, making it 2.8 times stronger than in wet cases during the 5 days preceding its peak.
• Strong Chaco jets transport approximately 37.9 gigatonnes of water daily.

Contributions

• Highlights the critical importance of land-atmosphere interactions, specifically antecedent soil moisture, in modulating the dynamics of the South American low-level jet.
• Shifts the research focus from predominantly atmospheric controls to include significant land surface processes in understanding SALLJ variability.
• Suggests that incorporating antecedent soil moisture information could significantly improve forecasts of Chaco jet events in the region.

Funding

Not specified in abstract.

Citation

@article{Chen2025Impact,
  author = {Chen, Chu‐Chun and Domínguez, Francina and Matus, Sean},
  title = {The Impact of Large‐Scale Land Surface Conditions on the South American Low‐Level Jet},
  journal = {Geophysical Research Letters},
  year = {2025},
  doi = {10.1029/2025gl116905},
  url = {https://doi.org/10.1029/2025gl116905}
}