几种气温客观预报方法对比及最优集成预报研究

Comparison of Several Objective Methods and Optimal Consensus Forecast Study of Temperature

由于模式本身的误差以及地形等影响,对模式产品进行订正释用是提高气温客观预报准确率的重要手段。基于ECMWF细网格预报产品研发了气温偏差订正和准对称混合滑动训练期MOS预报系统,在此基础上,设计了一种气温最优集成预报方法。对不同模式和不同客观方法的日最高、最低气温预报准确率进行了对比分析,结果表明:通过10~30 d的偏差滑动订正可以较好提高ECMWF细网格模式日最高、最低气温预报准确率。偏差滑动订正在短期内订正效果较显著,对考核站和鲁中山区订正效果尤其明显,对最低气温预报订正效果好于最高气温。MOS客观预报对日最高、最低气温预报也有较好的订正效果,但ECMWF细网格、偏差订正、MOS客观预报产品在不同地区、不同季节预报准确率有所不同,采用动态最优集成的方法进行最优集成预报,可以集成不同客观方法的预报优势,在多种客观预报产品的基础上再次提高预报准确率,达到最优集成的目的。

Correcting and interpreting the model’s temperature forecast is an important means of improve the accuracy rate of objective temperature forecast in the context of model’s system error and impact of terrain.In this paper bias correction and the quasi-symmetrical mixed running training period MOS forecast systems are developed based on ECMWF fine-resolution model products.With the different methods an optimal consensus forecast method of temperature is designed.The accuracy rates of different models and different objective methods of daily maximum and minimum temperatures are compared.The results show that bias running correction of daily maximum and minimum temperature forecast in 10 to 30 days can improve the ECMWF fine-resolution model’s temperature forecast.Bias running correction can significantly improve the daily maximum and minimum temperature forecasts of the models in short range,especially for the central mountainous area and check stations of Shandong Province.Bias running correction of daily minimum temperature can give higher improvement of the model’s forecast than that of daily maximum temperature.The MOS system can improve the daily maximum and minimum temperature forecasts too,while the accuracy rates of ECMWF fine-resolution model,bias correction and MOS temperature objective forecast are different for different regions and different seasons in Shandong Province.Running optimal consensus forecast method can give further improvement of daily maximum and minimum temperature forecasts by integrating the advantages of different objective methods.