小波变换在风廓线雷达探测大气边界层高度中的应用研究  

THE DETECTION OF THE ATMOSPHERIC BOUNDARY LAYER HEIGHT USING WIND PROFILER IN WAVELET TRANSFORM METHOD

作　　者：魏浩[1] 胡明宝[1] 艾未华[1,2] 

机构地区：[1]解放军理工大学气象海洋学院,江苏南京211101 [2]江苏省气象探测与信息处理重点实验室,江苏南京210044

出　　处：《热带气象学报》2015年第6期811-820,共10页Journal of Tropical Meteorology

基　　金：江苏省气象探测与信息处理重点实验室开放基金(KDXS1307);江苏省气象科学研究所北极阁基金(BJG201407);国家自然科学基金面上项目(41475019)共同资助

摘　　要：大气边界层的高度是污染物扩散模式、气候模式、大气模式的一个重要输入参数,边界层高度的变化对数值预报中的物理过程,天气预报的诊断分析,城市污染物的监控也有相当重要的作用。然而,边界层高度的连续监测缺乏有力的手段,风廓线雷达凭借其高时间分辨率和空间分辨率,加上其能够连续探测等优点,可以成为连续监测边界层高度的有效工具。利用协方差小波变换对风廓线雷达距离订正后信噪比数据进行分析,来确定边界层的高度,并与无线探空仪确定的边界层高度进行比较,通过分析得到:(1)协方差小波变换应用于边界层高度的确定时,尺度因子a和平移因子b的选取很关键,不同的a和b值得到的结果可能差异很大,在计算过程中要仔细选择合适的值;(2)质量控制对正确判断边界层高度至关重要,好的质量控制方法可以起到剔除突变点的作用,使确定的边界层高度更符合实际情况;(3)在晴空条件下,如果边界层湍流不均匀及杂波影响较大时,梯度法将不适用,它容易受到大气湍流不稳定以及其他因素引起的信噪比突变而产生较大误差,而协方差小波变换法作为梯度法的改进,能够较好地确定边界层的高度;(4)通过质量控制,小波变换法和探空仪确定的高度很一致,两者的相关系数达到0.87。The height of the atmospheric boundary layer is an important input parameter in pollutant dispersion models, climate models, and atmospheric models. The variation of the boundary layer height（BLH） is also important to the physical processes of numerical prediction, the diagnosis of weather forecasts and the monitoring of urban pollutants. However, there is still lack of effective means in monitoring the BLH. Wind profilers can be an effective tool for continuous monitoring of the BLH because of their high temporal and spatial resolution, coupled with its capability of conducting continuous detection. In this paper, the method of covariance wavelet transform is used to analyze the range-corrected signal-to-noise ratio of the wind profiler to determine the BLH, and then the results with the gradient method are compared with that with the radiosonde. The results are as follows：（1） The scale factor ＂a＂ and shift factor ＂b＂ are critical in the covariance wavelet transform. Different values may get completely different results.（2） The quality control of the BLH is crucial in this method. Good quality control can remove mutation points.（3） If the atmospheric turbulence is inhomogeneous, noise impact is large and under clear-sky conditions, the gradient method is not applicable, while the covariance wavelet transform method works well.（4） With quality control, the BLH is very consistent between the covariance wavelet transform and the radiosonde method, with the correlation coefficient between them being 0.87.

关 键 词：协方差小波变换 风廓线雷达 边界层高度 探测 

分 类 号：P404[天文地球—大气科学及气象学]