1.National Meteorological Center;2.Xiamen Airlines Co,Ltd
为提升对飞机颠簸的客观预报能力，设计一种新的基于湍能耗散率（Energy Dissipation Rate，EDR）的航空颠簸集成预报算法，预报结果可实现与机载探测到的新型颠簸实况直接对比验证，且预报强度不受机型差异的影响。该算法利用中国气象局中尺度天气数值预报（CMA-MESO）的基本气象要素计算多个代表晴空颠簸(Clear air Turbulence，CAT)和山地波 (Mountain wave Turbulence，MWT)的预报指数，在颠簸实况EDR和各预报指数的概率密度函数均基本符合正态分布的假设条件下，利用前期各指数和实况之间的概率密度匹配关系，将原预报指数在实时数值预报中转换为以EDR为单位的预报值；再将其根据预报评分给予不同权重，集成为包含晴空颠簸和山地波的EDR颠簸预报产品。主客观检验结果均显示这种颠簸预报产品能够大致反映不同区域和类型的颠簸情况，多种算法的集成预报报效果总体好于单一指数预报；相对作用特征检验(ROC)表明轻度以上颠簸的预报结果可以提高命中率并降低空报率，具有较高的预报正技巧。
In order to improve the objective prediction ability of aircraft turbulence, a new aviation turbulence ensemble prediction algorithm based on Energy dissipation rate (referred to as EDR) is designed. The forecast value can be directly compared and verified with the new turbulence data (EDR) obtained by airborne detection, and the forecast intensity is not affected by the difference of the aircraft type. The algorithm calculates multiple forecast indexes representing Clear-Air Turbulence(CAT) and Mountain Waves Turbulence(MWT) using the basic meteorological elements of the Mesoscale Weather Numerical Forecast System of CMA(CMA-MESO) .Under the assumption that the predicted turbulence diagnostics and EDR observations both approximately follow normal distribution，According to the probability density matching relationship between previous forecast indexes and EDR observations,the original forecast index is converted into the forecast value with EDR in the real-time numerical forecast. Multiple forecast indexes are given different weights according to the forecast scores, and they are integrated into EDR turbulence forecast products including clear sky turbulence and mountain waves. Subjective and objective verification results show that this turbulence forecast product can roughly reflect the turbulence in different regions and types. The integration prediction of multiple algorithms is generally better than that of single index forecast.The resulting Relative Operating Characteristics(ROC) curves shows that the forecast results of light-or-greater turbulence increase the hit rate and reduce the false alarm rate, and it has high forecasting skills.