Rehbein et al. (2026) South American Mesoscale Convective Systems: Present and Future Climates

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

Identification

• Journal: Journal of Geophysical Research Atmospheres
• Year: 2026
• Date: 2026-03-31
• Authors: Amanda Rehbein, Tércio Ambrizzi, Andreas F. Prein
• DOI: 10.1029/2025jd045438

Research Groups

Not explicitly mentioned in the abstract.

Short Summary

This study projects future changes in mesoscale convective systems (MCSs) over South America, finding a general intensification with higher maximum precipitation rates and larger precipitation volumes, alongside regional and seasonal shifts in their occurrence and precipitation contribution.

Objective

• To investigate how mesoscale convective systems (MCSs) over South America will change in a future climate, specifically regarding their occurrence, precipitation contribution, maximum precipitation rates, and precipitation volume.

Study Configuration

• Spatial Scale: South America, including subregions such as Northwest South America (NWS), North South America (NSA), southern Brazil, and the South America Monsoon region (SAM).
• Temporal Scale: Future climate projections, analyzed seasonally (austral summer (DJF), austral winter (JJA)) and during transition months (SON, MAM).

Methodology and Data

• Models used: Weather Research and Forecasting (WRF) regional model with dynamical downscaling and pseudoglobal warming; Nonhydrostatic Icosahedral Atmospheric Model (NICAM) global cloud-resolving model within the Coupled Model Intercomparison Project (CMIP6) High Resolution Model Intercomparison Project (HighResMIP) framework.
• Data sources: Not explicitly mentioned in the abstract, but based on model simulations.

Main Results

• Mesoscale convective systems (MCSs) in a future climate are projected to exhibit higher maximum precipitation rates and larger precipitation volumes across South America.
• This intensification of MCSs with increasing temperatures is consistent with previous studies.
• Statistically significant changes are spatially limited, with robust signals common to both models restricted to specific regions and seasons.
• Increases in MCS occurrence and precipitation proportion are mainly projected over Northwest South America (NWS) and North South America (NSA), particularly during the austral summer (December-January-February).
• Over southern Brazil, MCS occurrence and precipitation proportion are projected to increase during the austral winter (June-July-August).
• Decreases in MCS occurrence and precipitation proportion are found over the South America Monsoon region (SAM), especially during the transition months from dry to wet season (September-October-November) and wet to dry season (March-April-May).

Contributions

• Utilizes two distinct, high-resolution modeling approaches (WRF with pseudoglobal warming and NICAM within HighResMIP) to project future changes in MCSs over South America.
• Provides a detailed regional and seasonal analysis of multiple MCS characteristics, including occurrence, precipitation contribution, maximum precipitation rates, and precipitation volume.
• Identifies the spatial extent of robust, model-consistent signals for MCS changes and highlights regions and seasons where these signals are most significant.
• Offers specific regional and seasonal projections for MCS changes, including insights into potential influences of warmer temperatures on winter climate at the mesoscale level over southern Brazil.

Funding

Not mentioned in the abstract.

Citation

@article{Rehbein2026South,
  author = {Rehbein, Amanda and Ambrizzi, Tércio and Prein, Andreas F.},
  title = {South American Mesoscale Convective Systems: Present and Future Climates},
  journal = {Journal of Geophysical Research Atmospheres},
  year = {2026},
  doi = {10.1029/2025jd045438},
  url = {https://doi.org/10.1029/2025jd045438}
}