What the study found
An eight-member ensemble of CMIP6 climate models projected a marked intensification of precipitation extremes in the Kosi Basin, especially in the far future under SSP585, a high-emissions scenario. The study also found that this ensemble gave the best balance of accuracy and uncertainty reduction.
Why the authors say this matters
The authors conclude that index-specific model evaluation and optimal ensemble selection are important for producing reliable regional climate projections. They say these results support water resource planning and climate adaptation strategies.
What the researchers tested
The researchers assessed thirteen statistically downscaled and bias-corrected CMIP6 global climate models for their ability to reproduce eight ETCCDI precipitation indices, which are standard measures of precipitation extremes. They used eight statistical indicators with objective weights from the CRITIC method, then applied four multi-criteria decision-making methods: TOPSIS, VIKOR, EDAS, and PROMETHEE-II.
What worked and what didn't
MPI-ESM1-2-HR, INM-CM5-0, and BCC-CSM2-MR performed best overall, while ACCESS-CM2 and NorESM2 variants showed weaker agreement. The eight-member ensemble (AMME8) best reproduced the observed relationships among precipitation extremes and achieved the optimal symmetric uncertainty. Future projections from AMME8 showed increases of up to 47% in annual precipitation, 60% in heavy rainfall days, and nearly 79% in extremely wet days by 2061–2100 under SSP585.
What to keep in mind
The abstract does not provide detailed limitations beyond noting uncertainty among CMIP6 models and the need for careful evaluation. The findings are specific to the Kosi River Basin and to the models, indices, and scenarios examined.
Key points
- An eight-member CMIP6 ensemble (AMME8) gave the best balance of accuracy and uncertainty reduction.
- MPI-ESM1-2-HR, INM-CM5-0, and BCC-CSM2-MR ranked among the best-performing models.
- ACCESS-CM2 and NorESM2 variants showed weaker agreement with observed precipitation indices.
- Future projections indicated stronger precipitation extremes under both SSP245 and SSP585.
- Under SSP585 in 2061–2100, increases reached up to 47% in annual precipitation, 60% in heavy rainfall days, and nearly 79% in extremely wet days.
Disclosure
- Research title:
- CMIP6 models project stronger precipitation extremes in the Kosi Basin
- Authors:
- Aditya Kumar Singh, Thendiyath Roshni, Vivekanand Singh
- Institutions:
- National Institute of Technology Patna
- Publication date:
- 2026-03-08
- OpenAlex record:
- View
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