摘要: |
基于2019年8月至2020年7月华南区域模式(CMA-GD)预报和湖南97个国家站2m温度实况,开展了模式温度预报检验和逐步回归订正技术研究。结果表明,华南区域模式2m温度预报与实况变化趋势基本一致,预报偏差具有明显日变化,白天准确率下降、夜间升高,随着预报时效的延长,偏差增大;夏半年预报偏差大于冬半年;湘西预报效果优于湘东;00时起报的2m温度预报优于12时起报。基于华南区域模式预报产品,区分起报时次和季节的2m温度预报逐步回归订正预报效果较好,订正后预报相对于模式预报误差下降、准确率提高,有明显正技巧,对12时起报的模式预报效果改善更大,不同站点订正效果略有差异,对预报误差较大站点,订正效果明显。 |
关键词: 华南区域模式;2 m温度;逐步回归;温度订正 |
DOI: |
投稿时间:2022-02-11修订日期:2022-07-15 |
基金项目:泛珠三角区域模式预报发展专项(201906),湖南省重点领域研发计划项目(2019SK2161) |
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Bias Analysis and Correction Method for the 2 m Temperature Forecast in Hunan of Region Model in South China |
Chen Long,Chen Jingjing,Lan Mingcai,Zhou Changqing,Fu Wei |
(Hunan Meteorological Observatory;China;;Meteorological Disaster Prevention and Reduction Key Laboratory of Hunan Province;China;;Yongzhou Meteorological Observatory of Hunan Province;China) |
Abstract: |
Using the forecast data of regional model in South China (CMA-GD) and the 2m temperature observation data of 97 national stations in Hunan from August 2019 to July 2020, the hourly 2m temperature forecast of CMA-GD was evaluated and corrected in Hunan by using the stepwise regression method. The results show that the forecast bias of the 2m temperature of CMA-GD has obvious diurnal variation, because the forecast accuracy decreases in the day and increases in the night. The deviation increases with the extension of the forecast time. The forecast deviation is larger in summer. The forecast in the western Hunan is better than in the eastern Hunan being affected by the terrain and the model deviation. It`s better the 2m temperature forecast from 00:00 than that of from 12:00(UTC). On the basis of the 2m temperature forecast of CMA-GD, a stepwise regression correction model is established by time, regardless of time period, and season. The correction forecast has obvious positive skills compared with the model forecast, because of being reduced of the error and significantly improved of the accuracy. |
Key words: CMA-GD; 2 m temperature; stepwise regression; temperature correction |