摘要
利用山东省内123个国家气象站2017年11月至2018年2月逐时观测地面温度对WRF模式08:00和20:00起报的2m温度进行检验,评估了预报时效为72h的逐时温度与日最低(高)温度的预报效果并初步分析了个别站点大值误差成因。结果表明:WRF模式08:00起报2m温度的准确率要高于20:00起报,白天预报的效果优于夜晚;鲁西北和半岛地区的2m预报温度的平均绝对误差总体低于鲁中和鲁南地区,全省大部分站点负误差比例高于正误差比例;WRF模式对于日最高温度的预报效果优于日最低温度;模式地形高度误差造成泰山站2m预报温度正误差较大,基于两种温度梯度方案对泰山站2m温度进行订正,订正后的平均绝对误差总体下降,利用单一的温度梯度在有的预报时刻出现负的订正效果,利用随预报时刻变化而变化的温度梯度在各预报时刻订正效果更为稳定;泰安站出现焚风时2m预报温度有较大负误差,这主要是受WRF模式泰山站地形高度误差影响;WRF模式在微山湖区域土地类型与真实土地类型存在差异是薛城站夜间2m温度负误差较大的重要因素之一。
The observation data of 123 stations in Shandong province from November 2017 to February 2018 was used to verify 2 m temperature forecast starting at 08:00 and 20:00,respectively based on the Weather Forecast and Research(WRF)model.The forecasting effects of hourly temperature at 2 m and the daily minimum and maximum temperatures were evaluated.The reasons for the large error at some stations were analyzed.The result shows that the accuracy of 2 m temperature forecasted from the WRF model starting at 08:00 is higher than that forecasted starting at 20:00.The forecasting effect in day-time is better than that at the night.The prediction effect in the northwest and peninsula region is better than that in the other region in Shandong province.The negative error rate of most stations is larger than the positive one.The forecasting effect of the daily maximum temperature is better than that of the daily minimum one.The terrain height error in the model is the main factor that makes a large positive error of 2 m forecasting temperature at Mountain Tai station.Two schemes based on temperature gradient are used to correct 2 m forecasting temperature at Mountain Tai station.After correction,the mean absolute error decreases generally.However,there is a negative effect in the correction in some forecasting cases when a single temperature gradient is used.The forecasting effect is more stable when using the temperature gradient changing with the forecasting time.Affected by the terrain height error in the model,the foehn cannot be simulated by the WRF model.When the foehn occurs in Taian station,very large negative errors of 2 m forecasting temperature occur.The difference of land type between the model and real situation is one of the most important reasons that make a large negative error of 2 m forecasting temperature at Xuecheng station at the night.
作者
夏凡
杨晓霞
刘诗军
肖明静
XIA Fan;YANG Xiao-xia;LIU Shi-jun;XIAO Ming-jing(Shandong Meteorological Scientific Institution,Ji′nan 250031,China;Shandong Meteorological Observatory,Ji′nan 250031,China)
出处
《气象与环境学报》
2019年第5期10-17,共8页
Journal of Meteorology and Environment
基金
山东省气象局青年基金项目(2017SDQN08)
山东省气象局面上项目(2016sdqxm08)共同资助
山东省气象科学研究所数值天气预报应用技术开放研究基金(SDQXKF2015M04)
关键词
WRF模式
2m温度
地形高度误差
焚风
水陆风
WRF model
2 m temperature
Terrain height error
Foehn
Water and land breeze
