Multi-Model Ensemble Prediction of Maximum and Minimum Temperature Using Machine Learning Approach for North-East India
摘要
A vital phase in reducing simulation uncertainty is to identify the most skillful GCMs based on their statistical ranking and create multi-model ensembles (MMEs). This research focuses on the statistical evaluation of 20 general circulation models (GCMs) under IPCC’s sixth assessment report. As observed data, daily temperature data from 1965 to 2014 were acquired from the India Meteorological Department (IMD). A gridded resolution of 2° × 2° was used to evaluate the maximum and minimum temperatures for North-East India. Absolute normalized mean bias deviation (ANMBD), normalized root mean square deviation (NRMSD), correlation coefficient (CC), and skill score (SS) were the performance metrics employed. To get a relative ranking, weights were assigned to each performance metric using the dynamic weights approach. Compromise Programming was employed to rank each grid individually, and a group decision-based method was adopted to rank all grids collectively. MMEs of GCMs are established using machine learning-based Support Vector Regression (SVR) and Random Forest Regression (RFR) techniques. For maximum temperature, ACCESS-ESM1-5, NESM3, and INM-CM5-0, and for minimum temperature, TaiESM1, IITM-ESM, and INM-CM5-0, were among the top 3 ranked GCMs. For the study area, RFR is preferable over SVR-based ML techniques. For MaxT and MinT, the optimal GCM number for generating MMEs is around 35% and 25% of the top-ranked GCMs, respectively.