What determines perceived value of seasonal climate forecasts? A theoretical analysis     

Antony Millner  Richard Washington   《Global Environmental Change》2011,21(1):209-218

Seasonal forecasts have potential value as tools for the management of risks due to inter-annual climate variability and iterative adaptation to climate change. Despite their potential, forecasts are not widely used, in part due to poor performance and lack of relevance to specific users’ decision problems, and in part due to a variety of economic and behavioural factors. In this paper a theoretical model of perceived forecast value is proposed and applied to a stylized portfolio-type decision problem with wide applicability to actual forecast users, with a view to obtaining a more complete picture of the determinants of perceived value. The effects of user wealth, risk aversion, and perceived forecast trustworthiness, and presentational parameters, such as the position of forecast parameter categories, and the size of probability categories, on perceived value is investigated. Analysis of the model provides several strong qualitative predictions of how perceived forecast value depends on these factors. These predictions may be used to generate empirical hypotheses which offer the chance of evaluating the model's assumptions, and suggest several means of improving understanding of perceived value based on qualitative features of the results.  相似文献   

Probabilistic radar rainfall nowcasts using empirical and theoretical uncertainty models          下载免费PDF全文

Qiang Dai  Miguel A. Rico‐Ramirez  Dawei Han  Tanvir Islam  Sara Liguori 《水文研究》2015,29(1):66-79

Weather radar has a potential to provide accurate short‐term (0–3 h) forecasts of rainfall (i.e. radar nowcasts), which are of great importance in warnings and risk management for hydro‐meteorological events. However, radar nowcasts are affected by large uncertainties, which are not only linked to limitations in the forecast method but also because of errors in the radar rainfall measurement. The probabilistic quantitative precipitation nowcasting approach attempts to quantify these uncertainties by delivering the forecasts in a probabilistic form. This study implements two forms of probabilistic quantitative precipitation nowcasting for a hilly area in the south of Manchester, namely, the theoretically based scheme [ensemble rainfall forecasts (ERF)‐TN] and the empirically based scheme (ERF‐EM), and explores which one exhibits higher predictive skill. The ERF‐TN scheme generates ensemble forecasts of rainfall in which each ensemble member is determined by the stochastic realisation of a theoretical noise component. The so‐called ERF‐EM scheme proposed and applied for the first time in this study, aims to use an empirically based error model to measure and quantify the combined effect of all the error sources in the radar rainfall forecasts. The essence of the error model is formulated into an empirical relation between the radar rainfall forecasts and the corresponding ‘ground truth’ represented by the rainfall field from rain gauges measurements. The ensemble members generated by the two schemes have been compared with the rain gauge rainfall. The hit rate and the false alarm rate statistics have been computed and combined into relative operating characteristic curves. The comparison of the performance scores for the two schemes shows that the ERF‐EM achieves better performance than the ERF‐TN at 1‐h lead time. The predictive skills of both schemes are almost identical when the lead time increases to 2 h. In addition, the relation between uncertainty in the radar rainfall forecasts and lead time is also investigated by computing the dispersion of the generated ensemble members. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

区域业务模式6 h降水预报检验方案比较   总被引：6，自引：0，他引：6       下载免费PDF全文

王雨  公颖  陈法敬  张昆  赵天昊 《应用气象学报》2013,24(2):171-178

对我国华东、华南、华北区域气象中心和中国气象局数值预报中心业务运行的区域模式2011年5—9月的6 h降水预报, 采用不同检验结果平均方案进行对比检验。对比结果表明:不同的检验结果平均方案基本不影响与中国气象局数值预报中心模式 (NMC-GRA) 在相同区域关于TS评分比较的相对检验结论,即当两个模式评分差距较大时,评分高的模式在两个方案中是一样的,但评分比较接近时,若有一个模式对该区大尺度降水预报较好时,则可能在新方案中有较高的TS评分,而此模式原方案评分则可能略低于局地小尺度降水预报较好的模式。但对于较少发生的强降水预报的预报偏差的评价有很大不同,当新方案的结果显示多数模式对强降水的预报偏少,原方案则可能显示偏多,说明模式对大尺度的强降水预报较实况偏少,但对小尺度局地降水的预报则可能偏多。  相似文献   

概率匹配平均法在山东强降水预报中的应用          下载免费PDF全文

荣艳敏  盛春岩  范苏丹  曲巧娜 《山东气象》2017,37(3):95-101

基于WRF集合预报系统开发了概率匹配平均降水产品,选取了山东省2014—2016年共13次强降水过程,检验评估了概率匹配平均法在山东省强降水预报中的综合表现。结果表明：对于不同的强降水过程,各预报产品的预报能力差异较大,尤其是对暴雨以上量级降水的预报存在较大偏差;概率匹配平均相对集合平均,对大雨以上量级降水预报有明显改善,较WRF确定性预报产品也有一定提高,对强降水预报具有一定指示意义;该方法的改进主要体现在对不同量级降水的调整上,尤其是强降水的落区,相对集合平均增大了强降水的范围和强度,但对整个区域的总降水量预报没有很好的改进作用。  相似文献   

基于天气预报的参考作物腾发量LS-SVM预测模型   总被引：6，自引：0，他引：6       下载免费PDF全文

张展羽  王声锋  段爱旺  王斌 《水科学进展》2010,21(1):63-68

利用最小二乘支持向量机(LS-SVM)方法,建立了基于天气预报的参考作物腾发量(ET₀)的预测模型.对广利灌区1997~2006年逐日气象信息中的天气类型和风速等级进行量化后,以不同天气预报信息作为输入量,建立10种验证方案,对2007年的逐日ET₀进行预测.经验证,方案1~方案7精度均令人满意,其中方案1精度最高.方案1的输入量为气温、天气类型、风速等级3项的预测值,该方案的模型预测值与计算值的统计参数分别为:均方根偏差E_RMS为0.5182 mm,相对偏差E_R为0.1878,决定系数R2为0.864 8,认同系数I_A为0.966 9,回归系数R_C为0.9867;方案7精度亦较好,且以上指标统计参数依次为0.6576 mm、0.2332、0.986 6、0.774 7及0.986 6,该方案输入量只有气温项,实用性很强.  相似文献   

Application of the Takagi–Sugeno fuzzy system for combination forecasting of river flow in semiarid mountain regions     

Lijie Zhang  Wenzhi Zhao  Zhibin He  Hu Liu 《水文研究》2009,23(10):1430-1436

Because of high spatial heterogeneity and the degree of uncertainty about hydrological processes in large‐scale catchments of semiarid mountain areas, satisfactory forecasting of daily discharge is seldom available using a single model in many practical cases. In this paper the Takagi–Sugeno fuzzy system (TS) and the simple average method (SAM) are applied to combine forecasts of three individual models, namely, the simple linear model (SLM), the seasonally based linear perturbation model (LPM) and the nearest neighbour linear perturbation model (NNLPM) for modelling daily discharge, and the performance of modelling results is compared in five catchments of semiarid areas. It is found that the TS combination model gives good predictions. The results confirm that better prediction accuracy can be obtained by combining the forecasts of different models with the Takagi–Sugeno fuzzy system in semi‐arid mountain areas. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

Cultural climatology and the representation of sky, atmosphere, weather and climate in selected art works of Constable, Monet and Eliasson     

John E. Thornes 《Geoforum》2008,39(2):570-580

The visual turn presents new challenges and methodologies for the pursuit of geography as we seek to communicate our ideas and understanding within and beyond the discipline. This paper attempts to show the potential importance of visual culture within a field that we may call cultural climatology. Cultural climatology seeks to explore the dialectic between society and atmosphere, weather and climate at a variety of temporal and spatial scales. A new visual approach to cultural climatology is presented as a possible way of stimulating conversations across the divide between the social and physical sciences. Images and visualisation assert their presence in the understanding, modelling and communication of many nature/culture debates, highlighting a need both for visual literacy across geography, and for social and physical scientists to share their visual methodologies. Cultural climatologists, like other scientists, need visual methodologies for both the critical construction and deconstruction of the images they wish to present and with which they are confronted. To illustrate the importance of visual literacy for cultural climatologists this paper introduces a sample of works from three artists: Constable, Monet and Eliasson. It shows how an exploration of their work (via a theory of pictures) could help to provide: firstly a methodology for understanding the cultural symbolism of skies and weather; secondly an assessment of the urban atmosphere in London at the turn of the 20th century and thirdly an example of the effective representation of atmosphere, weather and climate involving public participation and understanding. Lessons learned from deconstructing these works of art will then be used to suggest improvements in the visualisation of weather in the production and consumption of weather forecasts (thus, picturing theory).  相似文献   

Estimating and forecasting pre-fishery abundance of Atlantic salmon (Salmo salar L.) in the Northeast Atlantic for the management of mixed-stock fisheries     

Potter  E.C.E.; Crozier  W.W.; Schon  P-J.; Nicholson  M.D.; Maxwell  D.L.; Prevost  E.; Erkinaro  J.; Gudbergsson  G.; Karlsson  L.; Hansen  L.P.; MacLean  J.C.; O Maoileidigh  N.; Prusov  S. 《ICES Journal of Marine Science》2004,61(8):1359-1369

  相似文献   

A method to predict typhoon waves   总被引：2，自引：0，他引：2  

Yang Chuncheng  Dai Mingrui  Gao Zhihu  Cheng Zhan  Xu Fuxiang  Liu Yu  Li Fengjin  Li Jie  Su Dongfu  Zhang Dacuo  Xu Qichun 《海洋学报(英文版)》1995,14(2):167-180

Ａｍｅｔｈｏｄｔｏｐｒｅｄｉｃｔｔｙｐｈｏｏｎｗａｖｅｓ￥ＹａｎｇＣｈｕｎｃｈｅｎｇ；ＤａｉＭｉｎｇｒｕｉ；ＧａｏＺｈｉｈｕａ；ＣｈｅｎｇＺｈａｎ；ＸｕＦｕｘｉａｎｇ；ＬｉｕＹｕ；ＬｉＦｅｎｇｊｉｎ；ＬｉＪｉｅ；ＳｕＤｏｎｇｆｕ；ＺｈａｎｇＤａｃｕｏ...  相似文献   

递减平均法与一元线性回归法对ECMWF温度预报订正能力对比     

王丹  王建鹏  白庆梅  高红燕 《气象》2019,45(9):1310-1321

基于ECMWF细网格模式的定时最高(低)气温预报产品,针对2017年陕西99个国家级气象站的日最高(低)气温预报,检验和比较了递减平均法和一元线性回归法两种方法对气温预报误差的订正效果。结果表明,两种方法都显著地提高了日最高(低)气温的预报准确率,随着预报时效的延长,订正能力逐渐减弱。技巧评分与模式对气温的预报能力有显著的负相关关系,秦岭及其以南地区的日最高气温预报和秦岭以北地区的日最低气温预报的准确率偏低,其技巧评分一般超过40%,极大值超过70%。两种方法都有效降低了系统误差,较小误差范围的站次增多,较大误差范围的站次减少,对日最高气温在预报绝对误差≤2℃误差范围的订正能力较为突出,对日最低气温在预报绝对误差≥3℃误差范围的订正更有优势。一元线性回归法对日最高气温预报的订正能力略优于递减平均法,对日最低气温预报的订正能力不及递减平均法,利用这两种方法对气温预报进行混合订正的效果更佳。  相似文献