DOI: 10.5194/hess-20-4605-2016
Scopus记录号: 2-s2.0-84997419043
论文题名: A statistically based seasonal precipitation forecast model with automatic predictor selection and its application to central and south Asia
作者: Gerlitz L ; , Vorogushyn S ; , Apel H ; , Gafurov A ; , Unger-Shayesteh K ; , Merz B
刊名: Hydrology and Earth System Sciences
ISSN: 10275606
出版年: 2016
卷: 20, 期: 11 起始页码: 4605
结束页码: 4623
语种: 英语
Scopus关键词: Atmospheric pressure
; Atmospheric temperature
; Climatology
; Cluster analysis
; Data mining
; Decision trees
; Forecasting
; Nickel
; Oceanography
; Sensitivity analysis
; Surface waters
; Weather forecasting
; Automatic calibration
; Controlling mechanism
; Correlation coefficient
; Monsoonal precipitation
; North Atlantic oscillations
; Precipitation anomalies
; Sea surface temperature (SST)
; Seasonal precipitations
; Climate models
英文摘要: The study presents a statistically based seasonal precipitation forecast model, which automatically identifies suitable predictors from globally gridded sea surface temperature (SST) and climate variables by means of an extensive data-mining procedure and explicitly avoids the utilization of typical large-scale climate indices. This leads to an enhanced flexibility of the model and enables its automatic calibration for any target area without any prior assumption concerning adequate predictor variables. Potential predictor variables are derived by means of a cell-wise correlation analysis of precipitation anomalies with gridded global climate variables under consideration of varying lead times. Significantly correlated grid cells are subsequently aggregated to predictor regions by means of a variability-based cluster analysis. Finally, for every month and lead time, an individual random-forest-based forecast model is constructed, by means of the preliminary generated predictor variables. Monthly predictions are aggregated to running 3-month periods in order to generate a seasonal precipitation forecast. The model is applied and evaluated for selected target regions in central and south Asia. Particularly for winter and spring in westerly-dominated central Asia, correlation coefficients between forecasted and observed precipitation reach values up to 0.48, although the variability of precipitation rates is strongly underestimated. Likewise, for the monsoonal precipitation amounts in the south Asian target area, correlations of up to 0.5 were detected. The skill of the model for the dry winter season over south Asia is found to be low. A sensitivity analysis with well-known climate indices, such as the El Niño-Southern Oscillation (ENSO), the North Atlantic Oscillation (NAO) and the East Atlantic (EA) pattern, reveals the major large-scale controlling mechanisms of the seasonal precipitation climate for each target area. For the central Asian target areas, both ENSO and NAO are identified as important controlling factors for precipitation totals during moist winter and spring seasons. Drought conditions are found to be triggered by a cold ENSO phase in combination with a positive state of NAO in northern central Asia, and by cold ENSO conditions in combination with a negative NAO phase in southern central Asia. For the monsoonal summer precipitation amounts over southern Asia, the model suggests a distinct negative response to El Niño events. © Author(s) 2016. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/78685
Appears in Collections: 气候变化事实与影响
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作者单位: GFZ German Research Centre for Geosciences, Section 5.4: Hydrology, Telegrafenberg, Potsdam, Germany
Recommended Citation:
Gerlitz L,, Vorogushyn S,, Apel H,et al. A statistically based seasonal precipitation forecast model with automatic predictor selection and its application to central and south Asia[J]. Hydrology and Earth System Sciences,2016-01-01,20(11)