Improving WRF-Chem PM2.5 predictions by combining data assimilation and deep-learning-based bias correction

Bibliographic Details
Title: Improving WRF-Chem PM2.5 predictions by combining data assimilation and deep-learning-based bias correction
Authors: Xingxing Ma, Hongnian Liu, Zhen Peng
Source: Environment International, Vol 195, Iss , Pp 109199- (2025)
Publisher Information: Elsevier, 2025.
Publication Year: 2025
Collection: LCC:Environmental sciences
Subject Terms: WRF-Chem, Bias correction, Data assimilation, PM2.5 concentrations, Optimization, Environmental sciences, GE1-350
More Details: In numerical model simulations, data assimilation (DA) on the initial conditions and bias correction (BC) of model outputs have been proven to be promising approaches to improving PM2.5 (particulate matter with an aerodynamic equivalent diameter of ≤ 2.5 μm) predictions. This study compared the optimization effects of these two methods and developed a new scheme that combines DA and BC simultaneously. Four parallel experiments were conducted during winter 2019: a control experiment directly forecasted by WRF-Chem (experiment name: WRF-Chem); an experiment that assimilated in situ observations based on the GSI (Gridpoint Statistical Interpolation) system (WRF-Chem_DA); an experiment with deep-learning-based BC (WRF-Chem_BC); and an experiment considering the combination of DA on the initial conditions and BC (WRF-Chem_DA_BC). Statistically, the accuracy of PM2.5 predictions could be optimized by both DA and BC for the first 24-h period, and WRF-Chem_BC performed better than WRF-Chem_DA in the initial field, especially in the period of 10–24 h, while the best performance was achieved by combining BC and DA. Throughout the initial 24-h period, compared with the control experiment, the results of WRF-Chem_DA_BC (WRF-Chem_DA, WRF-Chem_BC) showed an improvement in terms of root-mean-square error, with reduction proportions varying from 38.90 % to 48.86 % (18.88 % to 32.44 %, 30.10 % to 46.08 %). Besides having the best optimization effect over the whole domain, the combined method also performed well in different regions: during the forecasting period of 0–24 h, the RMSEs decreased from 32 % to 62 %, 39 % to 57 %, 28 % to 40 %, and 30 % to 49 % in the Beijing–Tianjin–Hebei, Yangtze River Delta, Central China, and Sichuan Basin urban agglomerations, respectively.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 0160-4120
Relation: http://www.sciencedirect.com/science/article/pii/S0160412024007864; https://doaj.org/toc/0160-4120
DOI: 10.1016/j.envint.2024.109199
Access URL: https://doaj.org/article/c69c9893a3d04345a538ba093a67e716
Accession Number: edsdoj.69c9893a3d04345a538ba093a67e716
Database: Directory of Open Access Journals
More Details
ISSN:01604120
DOI:10.1016/j.envint.2024.109199
Published in:Environment International
Language:English