Chakraborty et al. (2025) Game-theoretic diagnostic framework for monsoon climate stability: quantifying internal dynamics and external forcing

Identification

• Journal: Theoretical and Applied Climatology
• Year: 2025
• Date: 2025-10-28
• Authors: Dibya Chakraborty, Tilottama Chakraborty
• DOI: 10.1007/s00704-025-05856-7

Research Groups

• Hydro-Informatics Engineering, Civil Engineering Department, National Institute of Technology Agartala, Agartala, Tripura, India

Short Summary

This study introduces a novel game-theoretic framework to diagnose the intrinsic stability of a local climate system versus the influence of external forcing. It reveals a profound divergence between a theoretical Evolutionary Game Theory (EGT) model, which predicts a neutral equilibrium, and a standard Markovian model that accurately forecasts the empirically observed, skewed climate, demonstrating the overwhelming governance of external drivers.

Objective

• To pioneer the application of an Evolutionary Game Theory (EGT) framework to a high-frequency, single-point meteorological time series to diagnose its strategic structure.
• To formalize the local atmospheric system of Agartala, India, as a multi-player strategic game by defining discrete atmospheric states and constructing an empirical payoff matrix from their observed transition probabilities.
• To solve this game’s dynamics using the Replicator Equation to determine its theoretical Evolutionary Stable Strategy (ESS), representing the system’s equilibrium state if governed solely by internal dynamics.
• To critically compare this predicted equilibrium with the observed long-term climate record to quantify the influence of external factors.

Study Configuration

• Spatial Scale: Single-point monitoring station in Agartala, Northeast India.
• Temporal Scale: 12-year period, 3-hourly climate record.

Methodology and Data

• Models used: Evolutionary Game Theory (EGT) using the Replicator Equation (numerically solved with scipy.integrate.odeint), linear Markovian model for comparison.
• Data sources: Long-term hydro-meteorological data from the Indian Meteorological Department (IMD) official data portal (https://dsp.imdpune.gov.in/), including cloud cover ('TC') and rainfall ('RF').

Main Results

• The Evolutionary Game Theory (EGT) model, designed to isolate internal dynamics, predicts a perfectly neutral Evolutionary Stable Strategy (ESS) where all four atmospheric states ('Clear Sky', 'Cloudy & Dry', 'Overcast & Dry', 'Rainy') occur with a 0.25 proportion each.
• The empirically observed climate over 12 years is significantly skewed: 'Cloudy & Dry' dominates at 0.42, followed by 'Clear Sky' at 0.33, 'Rainy' at 0.14, and 'Overcast & Dry' at 0.12.
• A standard linear Markovian model, using the same transition data, accurately forecasts the empirically observed, skewed climate, with 'Cloudy & Dry' predicted at 0.420.
• This fundamental mismatch demonstrates that Agartala’s climate is not a closed system but is overwhelmingly governed by external drivers (e.g., the monsoon) that constantly push it away from its inherently neutral internal equilibrium.
• Experimental validation confirmed external forcing:
  • Seasonal segmentation showed season-specific ESSs (e.g., Winter ESS ~60% 'Clear Sky', Monsoon ESS >70% 'Rainy' and 'Overcast & Dry'), indicating seasonal modulation of internal dynamics.
  • ENSO phase stratification revealed significant shifts in 'Rainy' state frequency during monsoon (e.g., ~20% decrease in El Niño, ~15% increase in La Niña).
  • Residual analysis showed a strong positive correlation (r > 0.7) between the 'Rainy' state residual (deviation from neutral ESS) and a seasonal monsoon intensity index.
• Sensitivity analysis confirmed the robustness of the neutral ESS prediction to ±5% noise in the payoff matrix and to different transition window lengths (3, 6, 9, 12 hours).

Contributions

• Pioneers the application of Evolutionary Game Theory to high-frequency, single-point meteorological time series for diagnosing climate stability.
• Introduces a novel diagnostic framework that quantitatively disentangles a climate system's internal dynamics and resilience from the influence of external forcing factors.
• Establishes a theoretical baseline (neutral ESS) for internal climate behavior, allowing observed deviations to be interpreted as the integrated effect of external drivers.
• Offers a powerful new tool for comparative climatology and suggests potential for hybrid forecasting systems by coupling EGT with remote sensing and AI.

Funding

The authors declare that no funds, grants, or other support were received during the preparation of this manuscript.

Citation

@article{Chakraborty2025Gametheoretic,
  author = {Chakraborty, Dibya and Chakraborty, Tilottama},
  title = {Game-theoretic diagnostic framework for monsoon climate stability: quantifying internal dynamics and external forcing},
  journal = {Theoretical and Applied Climatology},
  year = {2025},
  doi = {10.1007/s00704-025-05856-7},
  url = {https://doi.org/10.1007/s00704-025-05856-7}
}