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L波段风廓线雷达采用相干累积技术提高雷达探测灵敏度,用于对降水云体垂直探测,能获取高分辨率的云体返回信号的全谱信息。应用它对2009年5月14日层状云降水过程中出现的零度层亮带进行了连续探测研究,得到零度层亮带附近区域中返回信号的谱参数(功率、平均多普勒速度、速度谱宽)和回波功率谱密度分布随高度的变化和演变特征。在零度层亮带区附近质点的冰水转化过程中,云体中大部分冰晶、雪花从-1.3℃附近开始表面融化,0.8℃附近冰晶、雪花的整体冰框架开始破碎分离成尺度较小的液态降水质点,3.5℃附近冰晶、雪花全部融化为液态降水质点。同时,在0.8℃附近约300m厚度的层次中观测到回波强度谱区范围突然展宽现象,这反映出降水质点的冰水转化引起局部环境强烈降温可能导致出现少量的细部对流现象。
The L-band wind profiler radar uses coherent accumulation technique to improve the radar detection sensitivity, which is used to detect the precipitation cloud vertically and obtain the full-spectrum information of the high-resolution cloud return signal. The application of this method to continuous detection of the zero-band bright band appearing in the stratified cloud precipitation process on May 14, 2009 has obtained the spectral parameters (power, average Doppler velocity, velocity Spectral width) and echo power spectral density distribution with the height of the evolution and evolution characteristics. During the ice water conversion process near the bright zone, the most ice crystals and snowflakes in the cloud melt from around -1.3 ℃, and the whole ice frame of ice crystals and snowflakes near 0.8 ℃ begin to crush and separate into smaller scale Liquid precipitation point, 3.5 ℃ near the ice crystals, snow all melted into liquid precipitation point. At the same time, a sudden broadening of the echo intensity spectral range was observed at a depth of about 300 m near 0.8 ° C. This shows that the intense cooling of the local environment caused by the ice water conversion of the precipitation point may result in a small amount of fine convection.