Justino et al. (2026) Hydroclimatic influence of atmospheric rivers on vegetation and wildfire susceptibility across South America

Identification

• Journal: Weather and Climate Extremes
• Year: 2026
• Date: 2026-09-08
• Authors: Flavio Barbosa Justino, Carlos Diego Gurjão, Wagner Flauber
• DOI: 10.1016/j.wace.2026.100953

Research Groups

• Federal University of Viçosa, Department of Agricultural Engineering, Brazil
• Atto Technology, São José dos Campos, SP, Brazil

Short Summary

This study investigates the role of atmospheric rivers (ARs) in modulating precipitation and wildfire activity across South America. The results reveal widespread declines in AR frequency and AR-associated precipitation across much of the continent, particularly during March–May and June–August.

Objective

• Investigate the influence of atmospheric rivers on vegetation dynamics, fuel accumulation, and wildfire susceptibility across South America

Study Configuration

• Spatial Scale: Continental scale, with a focus on eight major hydroclimatic regions: Amazon Basin, Northern/Central Andes, Brazilian savanna (Cerrado), Pantanal, Gran Chaco, Caatinga, Southern Andes, and Patagonia.
• Temporal Scale: 1979–2022 for large-scale atmospheric conditions, and 2001–2020 for satellite observations

Methodology and Data

• Models used: ERA5 reanalysis dataset
• Data sources: Satellite-derived vegetation indices (NDVI, NDWI), burned area, fire counts, and precipitation data from MODIS and ERA5

Main Results

• Widespread declines in AR frequency and AR-associated precipitation across much of the continent
• Dual role of ARs in regional fire dynamics: short-term increases in AR-associated precipitation suppresses fire activity, while longer-term increases stimulate vegetation growth and fuel accumulation, increasing wildfire susceptibility
• Variations in AR activity are accompanied by large-scale circulation anomalies, including upper-level trough–ridge patterns and changes in Integrated Vapor Transport (IVT)

Contributions

• This study provides evidence that atmospheric rivers may act as an important physical pathway linking synoptic-scale moisture transport with seasonal ecosystem responses and subsequent wildfire activity
• The results advance the understanding of compound weather and climate extremes by demonstrating how transient atmospheric moisture transport can trigger cascading impacts on terrestrial ecosystems

Funding

• Not specified in the provided text

Citation

@article{Justino2026Hydroclimatic,
  author = {Justino, Flavio Barbosa and Gurjão, Carlos Diego and Flauber, Wagner},
  title = {Hydroclimatic influence of atmospheric rivers on vegetation and wildfire susceptibility across South America},
  journal = {Weather and Climate Extremes},
  year = {2026},
  doi = {10.1016/j.wace.2026.100953},
  url = {https://doi.org/10.1016/j.wace.2026.100953}
}