| 基于2017年5月7日广州特大暴雨分析影响半径对集合卡尔曼滤波方法同化效果的影响 |
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| 引用本文： | 李霁杭,肖辉,万齐林,高郁东,吴亚丽.基于2017年5月7日广州特大暴雨分析影响半径对集合卡尔曼滤波方法同化效果的影响[J].热带气象学报,2019,35(1):73-88. |
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| 作者姓名： | 李霁杭 肖辉 万齐林 高郁东 吴亚丽 |
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| 作者单位： | 中国气象局广州热带海洋气象研究所/广东省区域数值天气预报重点实验室, 广东 广州 510640 |
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| 基金项目： | 国家重点基础研究发展规划(973计划)2015CB452802国家自然科学基金41475102国家自然科学基金41675099国家自然科学基金41475061广东省科技计划项目2017B020218003广东省科技计划项目2017B030314140广东省自然科学基金2016A030313140广东省自然科学基金2017A030313225广东省气象局科研项目GRMC2017Q01 |
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| 摘 要： | 集合卡尔曼滤波（EnKF）目前在资料同化的科研和业务中已得到广泛应用，可为集合预报提供较好的初始场，其影响半径的选取对同化结果影响显著。2017年5月7日在珠三角（珠江三角洲）一带出现极强降水，尤以广州的花都、黄埔、增城区为盛，甚至出现了极为罕见的特大暴雨。以本次极强降水过程为例，分析影响半径对EnKF同化效果的影响。结果发现利用EnKF方法同化观测站的10 m风和2 m温度资料后，可以较好地模拟出此次强降水过程，但仍存在着位置偏南，强度偏大，局地虚报和过报的现象。当水平影响半径取值过大时，大量虚假信息引入，产生过犹不及的效果，使得强降水过程南移较快，最终导致降水落区显著偏南偏东。且水平影响半径对模拟效果极为重要，因此取值要适当。
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| 关 键 词： | 五七暴雨 集合卡尔曼滤波 资料同化 影响半径 |
| 收稿时间： | 2017-12-07 |
ANALYSIS OF THE EFFECT OF INFLUENCE RADIUS ON THE ENSEMBLE KALMAN FILTER ASSIMILATION BASED ON A HEAVY RAINFALL ON MAY 7TH, 2017 IN GUANGZHOU |
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| Institution: | Guangzhou Institute of Tropical and Marine Meteorology/ Key Laboratory of Regional Numerical Weather Prediction, Guangzhou 510640, China |
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| Abstract: | The Ensemble Kalman Filtering (EnKF) has been widely used in data assimilation. It can provide a better initial field for ensemble prediction, and the influence radius has a significant impact on the assimilation results. On May 7th, 2017, there was a very heavy precipitation in the Pearl River Delta, especially in Huadu, Huangpu, and Zengcheng, where there was even a very rare torrential rain. Taking the process of this extremely heavy rainfall as example, this paper analyzed the effect of the influence radius on the assimilation with EnKF. The results show that the heavy rainfall process can be simulated well by assimilating observation with the EnKF. However, it still existed that the precipitation was located more to the south. Moreover, the rainfall intensity was too large, with false or over-predicted amounts in some areas. When the value of influence radius was too large, a large number of false information may cause the rapid movement of heavy rainfall to the south. Furthermore, it may result in more southward and eastward location of the precipitation area. The horizontal influence radius was very important to the simulation effect, so the value should be appropriate. |
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