京津冀城市群地区夏季低层大气风速谱特征分析  

Analysis of spectral characteristics for wind velocity in the low layer of the atmosphere in the Beijing-Tianjin-Hebei city cluster area during summer

作　　者：李炬[1] 曹晓彦[1] 程志刚[1] 窦军霞[1] 张京江[1] 

机构地区：[1]中国气象局北京城市气象研究所,北京100089

出　　处：《地球物理学报》2016年第5期1553-1565,共13页Chinese Journal of Geophysics

基　　金：公益性行业(气象)科研专项经费GYHY201106050;国家国际科技合作专项2015DFA20870资助

摘　　要：利用京津冀城市群地区6个观测站风廓线雷达夏季一个月同步观测资料,对其进行了风功率谱和小波分析.越接近地面,测站之间风的周期变化特征差异越明显,离地面越远,差异不显著.各站大于1天周期的频谱特征差异小,而小于1天周期的频谱特征差异大.各站频谱在几百米高度有明显日变化.不同位置的测站其日变化周期信号随高度分布表现为不同程度的地形影响效应.部分测站1km高度以下风功率谱在大于1天高频区近似满足-5/3幂分布规律.降水过程风频谱在低层普遍有小于1天的高频周期,这与降水过程高低空风速起伏和变化密切相关.各站平均风矢量日变化在5∶00—6∶00、20∶00—21∶00有明显风速变化和风向转换,1500m以下风向变化差异显著,偏南风出现时间及影响高度与该地区的山谷风和海陆风相联系.各站之间风速相关系数随高度分布呈现出低层低、上层高的特点.最后还给出了风廓线雷达布网建议.Power spectrum and wavelet were used to analyze data from 6wind profiler stations in the Beijing-Tianjin-Hebei city cluster area during summer 2010.The results show the differences of frequencies among 6stations are smaller closer to the ground,and bigger farther away from the ground.The differences of frequencies greater than 1-day are smaller than the frequencies less than 1-day.Obvious diurnal oscillations,which are different with locations of stations and effects by topography,are identified at hundreds meters level for all of stations.The spectra of some stations below 1km indicate-5/3power-law scaling regions for the frequencies higher than diurnal.High frequencies,less than 1day,at lower level usually are accompanied with rainfall,during which upper and lower winds oscillate and interact.Diurnal mean wind vectors show two wind transitions,which are 05-06hLST and 20-21hLST.More pronounced differences of wind directions are identified below 1500 m.Southerly winds occurrence and its depth are associated with mountain-valley breeze and sea breeze in this area. Wind speed correlation coefficients between stations increase with height.Suggestions for deploying wind profiler radars are given in this paper.

关 键 词：京津冀城市群 风廓线雷达 功率谱 小波分析 

分 类 号：P433[天文地球—大气科学及气象学]