Botetano et al. (2026) Large-scale climate drivers of extreme compound events in the Amazon from interannual to long-term timescales (1982–2024)

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

Identification

• Journal: Climate Dynamics
• Year: 2026
• Date: 2026-09-16
• Authors: G. Botetano, Jhan Carlo Espinoza, K. Takahashi, Ricardo A. Gutierrez-Villarreal, J. Marengo, S. Wongchuig
• DOI: 10.1007/s00382-026-08382-y

Research Groups

Not specified in the abstract.

Short Summary

This study documents a coherent compound hydroclimatic mode dominating Amazonian interannual variability, introducing the Amazon Basin Compound Hydroclimatic Extremes Index (AB-CHEX) to identify dry–hot and wet–cold states. It reveals distinct seasonal ocean–atmosphere drivers—ENSO for the wet season and Caribbean–Tropical North Atlantic sea surface temperature for the dry season—and highlights the unprecedented nature of the 2024 dry–hot event.

Objective

• To document the leading interannual variability of Amazonian precipitation, air temperature, river levels, and terrestrial water storage as a coherent compound hydroclimatic mode dominated by extreme events.
• To introduce the Amazon Basin Compound Hydroclimatic Extremes Index (AB-CHEX) to capture this variability and identify dominant hydroclimatic states.
• To analyze the seasonal evolution of these states and their linkages to large-scale ocean–atmosphere drivers.

Study Configuration

• Spatial Scale: Amazon Basin.
• Temporal Scale: 1982–2024.

Methodology and Data

• Models used: No specific predictive or simulation models mentioned. The study introduces and utilizes the Amazon Basin Compound Hydroclimatic Extremes Index (AB-CHEX) for analysis.
• Data sources: Observation-based data for precipitation, air temperature, river levels, and terrestrial water storage. Sea surface temperature variability (ENSO, Caribbean–Tropical North Atlantic) is also analyzed as a driver.

Main Results

• The leading interannual variability in Amazonian hydroclimate is represented by a coherent compound hydroclimatic mode characterized by extreme events.
• The Amazon Basin Compound Hydroclimatic Extremes Index (AB-CHEX) identifies two dominant states: dry–hot and wet–cold.
• A contrasting seasonal evolution is observed: wetter–colder conditions in the wet season (November–April) and increasingly dry–hot conditions in the dry season (June–September).
• Severe dry–hot events occurred in 1998 and 2016 during the wet season, and in 2005, 2010, and 2023 during the dry season. The 2024 event is unprecedented across both seasons.
• Spatially, 68% of the basin in the wet season and 76% in the dry season exhibit variability primarily characterized by compound hydroclimatic conditions.
• Distinct seasonal ocean–atmosphere drivers are identified: El Niño–Southern Oscillation (ENSO) dominates wet season variability through large-scale circulation changes. Caribbean–Tropical North Atlantic (TNA) sea surface temperature variability exerts primary regional control during the dry season, with secondary ENSO influence.
• The sustained warming of the Caribbean–TNA since the mid-2000s is suggested to intensify dry–hot compound extremes, reinforce land–atmosphere feedbacks, and amplify hydroclimatic instability, alongside an overall warming and drying trend.

Contributions

• Introduction of the Amazon Basin Compound Hydroclimatic Extremes Index (AB-CHEX) as a novel tool for monitoring and analyzing compound hydroclimatic extremes.
• Documentation of a coherent compound hydroclimatic mode as the leading interannual variability in Amazonia.
• Identification of distinct seasonal ocean–atmosphere drivers (ENSO for wet season, Caribbean–TNA SST for dry season) for compound hydroclimatic extremes in the Amazon.
• Highlighting the unprecedented nature and severity of the 2024 dry–hot event across both seasons.
• Suggestion of the intensifying role of sustained Caribbean–TNA warming in exacerbating dry–hot compound extremes and hydroclimatic instability.

Funding

Not specified in the abstract.

Citation

@article{Botetano2026Largescale,
  author = {Botetano, G. and Espinoza, Jhan Carlo and Takahashi, K. and Gutierrez-Villarreal, Ricardo A. and Marengo, J. and Wongchuig, S.},
  title = {Large-scale climate drivers of extreme compound events in the Amazon from interannual to long-term timescales (1982–2024)},
  journal = {Climate Dynamics},
  year = {2026},
  doi = {10.1007/s00382-026-08382-y},
  url = {https://doi.org/10.1007/s00382-026-08382-y}
}