一种偏差订正方法在平昌冬奥会气象预报的应用  

Application of a Bias Correction Method to Meteorological Forecast for the Pyeongchang Winter Olympic Games

作　　者：张玉涛 佟华 孙健 Zhang Yutao;Tong Hua;Sun Jian(National Meteorological Center,Beijing 100081;Numerical Weather Prediction Center of CMA,Beijing 100081)

机构地区：[1]国家气象中心,北京100081 [2]中国气象局数值预报中心,北京100081

出　　处：《应用气象学报》2020年第1期27-41,共15页Journal of Applied Meteorological Science

基　　金：国家重点专项研究发展计划(2018YFC1507605,2018YFF0300103);中国气象局数值预报青年基金“GRAPES模式产品误差订正技术在冬奥服务中的应用研究”;中国气象局数值预报(GRAPES)发展专项

摘　　要：为了提高GRAPES3 km(Global/Regional Assimilation and Prediction System)模式在2018年平昌冬奥会气象服务中的预报能力,采用一阶自适应的卡尔曼滤波方法对GRAPES_3km模式的2 m气温、2 m相对湿度和10 m风开展偏差订正。结果表明:偏差订正方法明显提高了地面要素的预报效果,其中2 m气温的均方根误差整体减小到2℃左右,站点订正改善率为10%~60%;10 m风速的均方根误差减小到2 m·s^-1左右,站点订正改善率为10%~45%;2 m相对湿度减小到20%以下,站点订正改善率为0~20%。与韩国气象厅LDAPS(Local Data Assimilation and Prediction System)及美国宇航局NU-WRF(NASA-Unified WRF)模式相比,GRAPES3 km模式的风速预报表现更为优异,各站点整体预报效果明显优于LDAPS和NU-WRF模式。偏差订正方法可有效改善模式在复杂地形条件下的预报能力,是提高精细化预报准确率的重要手段。The 23 rd Winter Olympics Games and the 13 th Winter Paralympic Games are held in Pyeongchang,South Korea during 9-25 February 2018 and 8-18 March 2018.Supported by the WMO(World Meteorological Organization)WWRP(World Weather Research Project Group),ICE-POP 2018(International Collaborative Experiments for Pyeongchang 2018 Olympic and Paralympic winter games)is organized by KMA(Korea Meteorological Administration),which aims to improve the forecasting ability of convective scale numerical models for high-impact weather system under complex terrain and to support weather forecasting and meteorological services during the Winter Olympics through international cooperation.GRAPES_3 km,a high-resolution model independently developed by CMA(China Meteorological Administration),participated in this project and provided real-time forecasting products at the specific sites during the Winter Olympics Games.In order to improve the forecasting ability of GRAPES_3 km,a bias correction method named one-order adaptive Kalman filtering is applied,which compensate for the fact that the resolution of GRAPES_3 km is not sufficient to simulate the complex terrain of the Winter Olympic Games and GRAPES_3 km doesn’t assimilate Korea’s observations due to some objective reasons such as data transmission.1-24-hour calibration products are provided twice a day,including 2 m temperature,2 m relative humidity,10 m wind speed,and 10 m wind direction on sixteen sites.The verification and evaluation are carried out in two aspects.First,it is to check whether the bias correction improves the accuracy of GRAPES_3 km,examined from the model’s diurnal cycle,daily variation and the forecast ability of complex terrain.Second,to the performance of calibrated GRAPES_3 km during the Winter Olympic Games is and examined compared to LDAPS model from KMA and NU-WRF from NASA,which shows that the high-resolution GRAPES_3 km model has abilities to simulate the near-ground elements in this service and the bias correction technology makes model products

关 键 词：GRAPES_3km模式 平昌冬奥会 ICE-POP 2018 偏差订正 

分 类 号：P45[天文地球—大气科学及气象学]