气象常规观测资料同化对江西近地层风速模拟的影响

The Impact of Meteorological Conventional Observation Data Assimilation on Simulating Near-Surface Wind Speed in Jiangxi Province

摘要:

本文引入中尺度模式WRF及微尺度气象模型calmet对江西省近地层风速进行模拟,采用WRF-3DVAR同化系统对常规气象观测资料同化,利用江西气象站及典型风场测风塔资料,检验了气象常规观测资料同化对风速模拟效果的影响。结果表明:同化后,江西省绝大部分地区10～70m各高度层年平均风速比未同化方案偏小0.3～1.6 m/s。同化气象常规观测资料对江西近地层风速模拟有所改进,同化后气象站模拟与实测风速相关系数较同化前提升0～0.28,偏差减少0.13～0.9 m/s,标准差减少0.03～1.08 m/s。鄱阳湖区测风塔低层(10 m)风速同化实验模拟效果优于未同化实验,但随着高度的增加,同化试验模拟的风速与观测值误差逐渐增大。对于海拔较高的赣南山地测风塔,10～70 m各高度层未同化试验的模拟效果优于同化试验。

Abstract:

In this paper, the mesoscale model WRF and microscale weather model calmet were interoduced to simulate the near ground wind speed in Jiangxi Province,using WRF-3DVAR assimilation system to assimilate conventional meteorological observation data. The influence of conventional observation data assimilation on wind speed simulation is tested using data from meteorological stations and wind measurement towers of typical wind farms in Jiangxi Province. The results show that: The results show that after assimilating conventional observation data, the annual average wind speed at various altitudes of 10-70m in most areas of Jiangxi Province is 0.3～1.6 m/s lower than that of the non assimilating scheme. The assimilation of conventional observation data has improved the simulation of near-surface wind speed in Jiangxi. Compared to before assimilation, after assimilation, the correlation coefficient between simulated and measured wind speeds at meteorological stations has increased by 0 to 0.28, with the deviation reduction of 0.13 to 0.9 m/s and the standard deviation reduction of 0.03 to 1.08 m/s. The simulation effect of the wind speed assimilation experiment at the lower level (10m) of the wind towers in Poyang Lake area is better than that of the non assimilation experiment, but with the increase of the height, the error between the wind speed simulated in the assimilation experiment and the observation value gradually increases. For the wind towers in the mountainous areas of Gannan with higher altitudes, the simulation effect of non assimilation experiments from 10 to 70 meters is better than that of assimilation experiments.