公里级CMA_MESO模式FSS评分技术研究

本文研究计算CMA_MESO模式预报降水FSS（Fractions Skill Score）评分时，当其水平分辨率与观测降水不一致时，采取两种匹配方式统一分辨率，分析这两种方式得到的FSS评分结果是否有差异。针对3 km分辨率CMA_MESO模式6 h累积降水，选取5 km分辨率的观测降水，分别采取预报降水匹配观测降水分辨率，以及观测降水匹配预报降水分辨率两种方式，选择4种邻域尺度：5、25、51和105 km；4种降水阈值：0.1、4、13和25 mm，得到两组不同预报时效的FSS评分。通过分析发现：两组FSS评分结果没有显著差异。研究结果表明，当CMA_MESO模式预报降水水平分辨率与观测降水不一致时，可以将预报降水匹配到观测降水格点场，也可以将观测降水匹配到预报降水格点场，两种匹配方式对FSS评分结果没有影响。

Fraction Skill Score Verification Technology for Kilometer-Level CMA_MESO Model

The purpose of this paper is to analyze whether the FSS(Fraction Skill Score) score results obtained by the two methods are different when the forecast precipitation FSS is calculated for the CMA_MESO model, its horizontal resolution is inconsistent with the observed precipitation, two matching methods are adopted to unify the resolution. In this paper, the forecast data are the 6 hour cumulative precipitation of the 3 km resolution CMA_MESO model, and the observed data is 5 km resolution observed precipitation. The two methods of forecast precipitation matching observed precipitation resolution and observed precipitation matching forecast precipitation resolution are adopted, respectively. Four neighbourhood scales are selected: 5 km, 25 km, 51 km and 105 km; and four precipitation thresholds are selected: 0.1 mm, 4 mm, 13 mm and 25 mm. Two groups of FSS scores with different prediction times are obtained. Through analysis, it is found that there is no significant difference in FSS score between the two groups. The results show that when the horizontal resolution of the prediction precipitation for the CMA_MESO model is inconsistent with the observed precipitation, the predicted precipitation can be matched to the observation grid field, and the observation can also be matched to the model grid field. The two methods do not affect the FSS score results.