Improving the Capability of CMIP6 Simulations for Compound Extreme Wind and Precipitation Events in the Eastern Coastal Region of China Using Deep Learning Methods

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  • 1. School of Atmospheric SciencesPlateau Atmosphere and Environment Key Laboratory of Sichuan ProvinceChengdu Plain Urban Me-teorology and Environment Observation and Research Station of Sichuan ProvinceSichuan Meteorological Disaster Prediction and Early Warning Engineering LaboratoryChengdu University of Information TechnologyChengdu 610225SichuanChina
    2. College of Ocean and MeteorologyGuangdong Ocean UniversityZhanjiang 524088GuangdongChina

Online published: 2025-04-11

Abstract

Relative to individual extreme weather and climate eventsCompound Wind and Precipitation ExtremesCWPE),which result from extreme winds and extreme precipitationhave a profound impact on the economy and daily life in coastal areas. In this studywe utilized the simulations from 17 models within the Coupled Model Intercomparison Project Phase 6CMIP6for the period 1961-2000 of CWPE in the eastern coastal region of China as a training setand established a Deep LearningDLmodel employing a multi-layer perceptron neural network. By constructing a loss function suitable for CWPE and optimizing the model accordinglywe have developed a DL model aimed at reducing the simulation bias and uncertainty of CMIP6 models for CWPE. The research results indicate that the majority of CMIP6 models possess a relatively good simulation capability for CWPE in the eastern coastal region of Chinawith the Multi-Model Ensemble MeanMME-Meanand the Multi-Model Ensemble MedianMME-Mediandemonstrating better performance in assessments com‐ pared to individual models. The DL model constructed with the Mean Squared ErrorMSEfunction as the loss function performs worse in terms of Taylor Skill ScoreTSand Root Mean Squared ErrorRMSEcompared to the statistical results of the Multi-Model Ensemble. Incorporating the Ratio of the Standard DeviationRSDfrom climate evaluation metrics and an underestimation constraint function into the MSE loss function can significantly enhance the performance of the DL model in terms of TS and RMSE. Thereforethe DL model trained with a weighted loss function constructed from MSERSDand underestimation constraint function is defined as DL-MRMwhile the DL model trained solely with MSE as the loss function is defined as DL-MSE. By com‐ paring and analyzing the performance of the two DL models in simulating CWPE over the eastern coastal region of China from 2001 to 2014as well as the performance of DL-MRM relative to multi-model ensemble methodswe conclude:(1Both DL models exhibit underestimation in their simulation resultsbut the bias of the DLMRM is lower than that of the DL-MSEbeing closer to the observations. Specificallyin the study areathe relative bias of the DL-MRM is lower than that of the DL-MSE by about 63%and the average relative bias is reduced by approximately 20%.2The DL-MRM has a lower overall bias compared to the MME-Mean and MME-Medianwith simulation results that are closer to the observations. In the study areathe DL-MRM has a lower relative bias in 67% and 62% of the area compared to the MME-Mean and MME-Medianrespectivelyand the average relative bias is reduced by approximately 10% and 20%respectively. Overallby integrating the RSD and underestimation constraint functions to construct a weighted loss function for model optimizationa DL model suitable for improving the simulation of CWPE by CMIP6 models was established. This indicates that the combination of deep learning methods can more effectively reduce the biases in CMIP6 model simulations of CWPE compared to traditional multi-model ensemble methods.

Cite this article

TAN Qichang, ZHANG Yu, GE Fei, JIAN Yifei, WU Yuyan, WANG Kangning . Improving the Capability of CMIP6 Simulations for Compound Extreme Wind and Precipitation Events in the Eastern Coastal Region of China Using Deep Learning Methods[J]. Plateau Meteorology, 0 : 1 . DOI: 10.7522/j.issn.1000-0534.2025.00029

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