DOI: 10.1175/JCLI-D-16-0652.1
Scopus记录号: 2-s2.0-85017509861
论文题名: How suitable is quantile mapping for postprocessing GCM precipitation forecasts?
作者: Zhao T. ; Bennett J.C. ; Wang Q.J. ; Schepen A. ; Wood A.W. ; Robertson D.E. ; Ramos M.-H.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2017
卷: 30, 期: 9 起始页码: 3185
结束页码: 3196
语种: 英语
Scopus关键词: Climatology
; Mapping
; Reliability
; Weather forecasting
; Climate prediction
; Ensembles
; Forecast verification/skill
; Operational forecasting
; Seasonal forecasting
; Forecasting
英文摘要: GCMs are used by many national weather services to produce seasonal outlooks of atmospheric and oceanic conditions and fluxes. Postprocessing is often a necessary step before GCM forecasts can be applied in practice. Quantile mapping (QM) is rapidly becoming the method of choice by operational agencies to postprocess raw GCM outputs. The authors investigate whether QM is appropriate for this task. Ensemble forecast postprocessing methods should aim to 1) correct bias, 2) ensure forecasts are reliable in ensemble spread, and 3) guarantee forecasts are at least as skillful as climatology, a property called "coherence." This study evaluates the effectiveness of QM in achieving these aims by applying it to precipitation forecasts from the POAMA model. It is shown that while QM is highly effective in correcting bias, it cannot ensure reliability in forecast ensemble spread or guarantee coherence. This is because QM ignores the correlation between raw ensemble forecasts and observations. When raw forecasts are not significantly positively correlated with observations, QM tends to produce negatively skillful forecasts. Even when there is significant positive correlation, QM cannot ensure reliability and coherence for postprocessed forecasts. Therefore, QM is not a fully satisfactory method for postprocessing forecasts where the issues of bias, reliability, and coherence pre-exist. Alternative postprocessing methods based on ensemble model output statistics (EMOS) are available that achieve not only unbiased but also reliable and coherent forecasts. This is shown with one such alternative, the Bayesian joint probability modeling approach. © 2017 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/49678
Appears in Collections: 气候变化事实与影响
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作者单位: CSIRO Land and Water, Clayton, VIC, Australia; CSIRO Land and Water, Dutton Park, QLD, Australia; National Center for Atmospheric Research, Boulder, CO, United States; Irstea, Hydrosystems and Bioprocesses Research Unit, Antony, France
Recommended Citation:
Zhao T.,Bennett J.C.,Wang Q.J.,et al. How suitable is quantile mapping for postprocessing GCM precipitation forecasts?[J]. Journal of Climate,2017-01-01,30(9)