Chavez et al. (2025) Simulating Stratiform Precipitation With Embedded Convection in High‐Elevation Valleys Using LES: The Role of Topographic Detail

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

Identification

• Journal: Journal of Geophysical Research Atmospheres
• Year: 2025
• Date: 2025-12-06
• Authors: Steven Chavez, Jose Flores Rojas, K. Takahashi, Yamina Silva
• DOI: 10.1029/2025jd043696

Research Groups

Not explicitly mentioned in the abstract.

Short Summary

This study uses large-eddy simulations to investigate how topographic detail influences precipitation distribution in the Mantaro Valley, Peru, finding that subtle subkilometer terrain variations critically modulate convection and stratiform precipitation processes, necessitating high-resolution topography in mountain rainfall models.

Objective

• To examine the role of topographic detail on the spatial distribution of precipitation in the Mantaro Valley, Peru.

Study Configuration

• Spatial Scale: Regional (Mantaro Valley, Peru), with terrain resolutions tested at 450 meters, 1,050 meters, and 1,650 meters.
• Temporal Scale: Evolution of convective and stratiform precipitation processes over periods of several hours, including cloud formation delays of 30–60 minutes.

Methodology and Data

• Models used: Cloud Model 1 (CM1) in large-eddy simulation (LES) mode with a two-moment microphysics scheme.
• Data sources: In situ soundings (for thermodynamic conditions), Ka-band radar reflectivity profiles (for validation).

Main Results

• Fine-resolution terrain (450 m) simulations generated larger amounts of ice, snow, and graupel within vortical structures, producing rainfall that matched Ka-band radar reflectivity profiles.
• Smoother terrains (1,050 m and 1,650 m) delayed cloud formation by 30–60 minutes and reduced ice-phase particle production, confining precipitation to the eastern slopes.
• Wind vortex analysis revealed smaller upper-level eddies (above 2 kilometers AGL) in the high-resolution case, which promoted enhanced mixing and hydrometeor growth.
• Subtle variations in terrain detail critically influence convection and stratiform precipitation processes in Andean valleys.

Contributions

• Demonstrates the critical influence of subkilometer topographic detail on convection and stratiform precipitation processes in high-elevation Andean valleys.
• Underscores the necessity for subkilometer representation of topography in high-mountain rainfall modeling.
• Provides insights into how terrain-induced wind vortices modulate hydrometeor growth and spatial precipitation distribution.

Funding

Not explicitly mentioned in the abstract.

Citation

@article{Chavez2025Simulating,
  author = {Chavez, Steven and Rojas, Jose Flores and Takahashi, K. and Silva, Yamina},
  title = {Simulating Stratiform Precipitation With Embedded Convection in High‐Elevation Valleys Using LES: The Role of Topographic Detail},
  journal = {Journal of Geophysical Research Atmospheres},
  year = {2025},
  doi = {10.1029/2025jd043696},
  url = {https://doi.org/10.1029/2025jd043696}
}