Cai et al. (2026) Contrasting responses of Eurasian extreme precipitation to climate change: a multi-regional assessment using NEX-GDDP-CMIP6

Identification

• Journal: Climate Dynamics
• Year: 2026
• Date: 2026-02-01
• Authors: Hui Cai, Shen’ao Li, Wenxuan Zhang, Xian Zhu
• DOI: 10.1007/s00382-026-08049-8

Research Groups

• School of Atmospheric Sciences and Key Laboratory of Tropical Atmosphere-Ocean System Ministry of Education Sun Yat-Sen University, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China

Short Summary

This study evaluates the NASA-NEX-GDDP-CMIP6 dataset's performance in simulating six extreme precipitation indices across four Eurasian regions (1985–2014) and projects future changes under Shared Socioeconomic Pathways (2071–2100), revealing contrasting hydroclimatic responses from increased monsoon extremes in South Asia to hydroclimatic whiplash in Central Asia.

Objective

• To assess how NEX-GDDP-CMIP6 improves extreme precipitation simulations compared to native CMIP6, particularly in regions with contrasting hydroclimates.
• To identify models with superior skill in capturing regional extreme precipitation and understand the underlying physical mechanisms.
• To project how Shared Socioeconomic Pathways (SSPs) modulate future precipitation extremes and derive implications for regional risk management.

Study Configuration

• Spatial Scale: Eurasia, specifically four climatically and geographically distinct regions: South Asia (SAS, 5° N–30° N, 60° E–95° E), East Asia (EAS, 20° N–50° N, 100° E–145° E), Central Asia (CAS, 35° N–58° N, 46° E–94° E), and Southeast Asia (SEA, -10° N–20° N, 95° E–155° E). Data resolution is 0.25° x 0.25° for NEX-GDDP-CMIP6, regridded to 0.5° x 0.5° for analysis.
• Temporal Scale: Historical period: 1985–2014. Future projections: 2015–2100, with specific focus on 2071–2100 for distant future changes.

Methodology and Data

• Models used:
  • NASA-NEX-GDDP-CMIP6 dataset (20 statistically downscaled models from CMIP6)
  • Native CMIP6 models (for comparison)
  • Bias Correction and Spatial Disaggregation (BCSD) method applied to CMIP6 outputs for NEX-GDDP-CMIP6.
  • Extreme precipitation indices (ETCCDI): Total wet-day precipitation (PRCPTOT), simple daily intensity index (SDII), maximum 1-day precipitation (Rx1day), maximum 5-day precipitation (Rx5day), consecutive dry days (CDD), and number of very heavy precipitation days (R20).
• Data sources:
  • NASA-NEX-GDDP-CMIP6 (primary precipitation source, 1950–2100 under SSP1-2.6, SSP2-4.5, SSP5-8.5 scenarios)
  • CPC Global Unified Gauge-based Analysis from NOAA (0.5° x 0.5°, 1979–2020)
  • GPCC Full Data Daily Version 2022 (1.0° x 1.0°, 1982–2020)
  • Climatic Research Unit (CRU)
  • NASA’s Gridded Population of the World Version 4 (GPWv4)
  • ETOPO Global Relief Model Version 2022

Main Results

• Historical Trends (1985–2014): All regions showed upward trends in total and extreme precipitation indices, except for CDD. South Asia (SAS) exhibited the most pronounced intensification: PRCPTOT increased by 42%, Rx1day by 28%, and Rx5day by 32%. Central Asia (CAS) showed minimal increases in wet-day extremes but a sharp surge in consecutive dry days (CDD), indicating escalating aridity.
• Model Performance: NEX-GDDP-CMIP6 multi-model ensembles (MMEs) captured the sign of observed trends for PRCPTOT, SDII, Rx5day, and R20 but consistently underestimated their magnitudes by 10–40%, particularly in arid CAS (due to unresolved soil moisture-precipitation feedbacks) and humid Southeast Asia (SEA, due to complex convective processes). NEX-GDDP-CMIP6 models significantly improved spatial pattern simulations over native CMIP6, with Taylor Skill Scores (TSS) increasing by 0.03–0.41, most notably for PRCPTOT (+0.31) and CDD (+0.41). Top-performing models varied regionally, with CESM2, EC-Earth3, and EC-Earth3-Veg-LR generally excelling.
• Future Projections (2071–2100 under SSP5-8.5):
  • South Asia (SAS) is projected to face a 29% surge in total precipitation, with monsoon extremes (Rx1day) accelerating 1.2 times faster than Rx5day, and significant declines in CDD.
  • Central Asia (CAS) is projected to experience hydroclimatic whiplash, with a 16% rise in extreme precipitation (R20 surges to 11.98% per decade) alongside prolonged droughts (CDD increases by 5.8%).
  • East Asia (EAS) and Southeast Asia (SEA) show moderate wetting (PRCPTOT +11–16%) but divergent drought risks, with SEA experiencing both extreme rain (+16.5%) and increased aridity (+27.4% CDD).
  • These nonlinear, emission-dependent responses underscore the need for region-specific adaptation strategies.

Contributions

• Provides the first comprehensive evaluation of the NASA-NEX-GDDP-CMIP6 dataset across Eurasia's diverse climatic and topographic gradients.
• Focuses on four distinct hydroclimatic regions (SAS, EAS, CAS, SEA) that represent monsoon-to-arid gradients and high population exposure to extreme precipitation.
• Enhances the comprehensiveness of model evaluation by integrating assessments across spatial patterns, temporal dynamics, and combined spatiotemporal analyses.
• Systematically assesses the effectiveness of multi-model ensembles and identifies superior individual models for regional applications.
• Offers novel insights into future changes in extreme precipitation across Eurasia using the NEX-GDDP-CMIP6 dataset, informing climate-resilient policymaking aligned with Sustainable Development Goals (e.g., SDG11 for flood-resilient infrastructure in monsoon regions, SDG6 for water storage systems in arid CAS).

Funding

No specific funding projects or programs were listed in the paper. Access to the article was provided by Consorci de Serveis Universitaris de Catalunya (CSUC).

Citation

@article{Cai2026Contrasting,
  author = {Cai, Hui and Li, Shen’ao and Zhang, Wenxuan and Zhu, Xian},
  title = {Contrasting responses of Eurasian extreme precipitation to climate change: a multi-regional assessment using NEX-GDDP-CMIP6},
  journal = {Climate Dynamics},
  year = {2026},
  doi = {10.1007/s00382-026-08049-8},
  url = {https://doi.org/10.1007/s00382-026-08049-8}
}