Skillful subseasonal ensemble predictions of heat wave onsets through better representation of land surface uncertainties

Abstract Uncertainties in land surface processes notably limit subseasonal heat wave (HW) onset predictions. A better representation of the uncertainties in land surface processes using ensemble prediction methods may be an important way to improve HW onset predictions. However, generating ensemble...

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Main Authors: Qiyu Zhang, Mu Mu, Guodong Sun
Format: Article
Language:English
Published: Nature Portfolio 2025-01-01
Series:npj Climate and Atmospheric Science
Online Access:https://doi.org/10.1038/s41612-024-00876-y
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author Qiyu Zhang
Mu Mu
Guodong Sun
author_facet Qiyu Zhang
Mu Mu
Guodong Sun
author_sort Qiyu Zhang
collection DOAJ
description Abstract Uncertainties in land surface processes notably limit subseasonal heat wave (HW) onset predictions. A better representation of the uncertainties in land surface processes using ensemble prediction methods may be an important way to improve HW onset predictions. However, generating ensemble members that adequately represent land surface process uncertainties, particularly those related to land surface parameters, remains challenging. In this study, a conditional nonlinear optimal perturbation related to parameters (CNOP-P) approach was employed to generate ensemble members for representing the uncertainties in land surface processes resulting from parameters. Via six strong and long-lasting HW events over the middle and lower reaches of the Yangtze River (MLYR), HW onset ensemble forecast experiments were conducted with the Weather Research and Forecasting (WRF) model. The performance of the CNOP-P approach and the traditional random parameter perturbation ensemble prediction method was evaluated. The results demonstrate that the deterministic and probabilistic skills of HW onset predictions show greater excellence using the CNOP-P approach, leading to much better predictions of extreme air temperatures than those using the traditional method. This occurred because the ensemble members generated by the CNOP-P method better represented the uncertainties in important land physical processes determining HW onsets over the MLYR, notably vegetation process uncertainties, whereas the ensemble members generated by the random parameter perturbation method could not. This finding suggests that the CNOP-P method is suitable for producing ensemble members that more appropriately represent model uncertainties through more reasonable parameter error characterization.
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spelling doaj-art-8a2a81c6ba5b4037b97c718c2caa951f2025-01-19T12:16:10ZengNature Portfolionpj Climate and Atmospheric Science2397-37222025-01-018111510.1038/s41612-024-00876-ySkillful subseasonal ensemble predictions of heat wave onsets through better representation of land surface uncertaintiesQiyu Zhang0Mu Mu1Guodong Sun2Key Laboratory of Core Tech on Numerical Model-AI Integrated Forecast for Hazardous Precipitation, Chongqing Institute of Meteorological SciencesDepartment of Atmospheric and Oceanic Sciences and Institute of Atmospheric Sciences, Fudan UniversityState Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics, Chinese Academy of SciencesAbstract Uncertainties in land surface processes notably limit subseasonal heat wave (HW) onset predictions. A better representation of the uncertainties in land surface processes using ensemble prediction methods may be an important way to improve HW onset predictions. However, generating ensemble members that adequately represent land surface process uncertainties, particularly those related to land surface parameters, remains challenging. In this study, a conditional nonlinear optimal perturbation related to parameters (CNOP-P) approach was employed to generate ensemble members for representing the uncertainties in land surface processes resulting from parameters. Via six strong and long-lasting HW events over the middle and lower reaches of the Yangtze River (MLYR), HW onset ensemble forecast experiments were conducted with the Weather Research and Forecasting (WRF) model. The performance of the CNOP-P approach and the traditional random parameter perturbation ensemble prediction method was evaluated. The results demonstrate that the deterministic and probabilistic skills of HW onset predictions show greater excellence using the CNOP-P approach, leading to much better predictions of extreme air temperatures than those using the traditional method. This occurred because the ensemble members generated by the CNOP-P method better represented the uncertainties in important land physical processes determining HW onsets over the MLYR, notably vegetation process uncertainties, whereas the ensemble members generated by the random parameter perturbation method could not. This finding suggests that the CNOP-P method is suitable for producing ensemble members that more appropriately represent model uncertainties through more reasonable parameter error characterization.https://doi.org/10.1038/s41612-024-00876-y
spellingShingle Qiyu Zhang
Mu Mu
Guodong Sun
Skillful subseasonal ensemble predictions of heat wave onsets through better representation of land surface uncertainties
npj Climate and Atmospheric Science
title Skillful subseasonal ensemble predictions of heat wave onsets through better representation of land surface uncertainties
title_full Skillful subseasonal ensemble predictions of heat wave onsets through better representation of land surface uncertainties
title_fullStr Skillful subseasonal ensemble predictions of heat wave onsets through better representation of land surface uncertainties
title_full_unstemmed Skillful subseasonal ensemble predictions of heat wave onsets through better representation of land surface uncertainties
title_short Skillful subseasonal ensemble predictions of heat wave onsets through better representation of land surface uncertainties
title_sort skillful subseasonal ensemble predictions of heat wave onsets through better representation of land surface uncertainties
url https://doi.org/10.1038/s41612-024-00876-y
work_keys_str_mv AT qiyuzhang skillfulsubseasonalensemblepredictionsofheatwaveonsetsthroughbetterrepresentationoflandsurfaceuncertainties
AT mumu skillfulsubseasonalensemblepredictionsofheatwaveonsetsthroughbetterrepresentationoflandsurfaceuncertainties
AT guodongsun skillfulsubseasonalensemblepredictionsofheatwaveonsetsthroughbetterrepresentationoflandsurfaceuncertainties