| When using the weather radar to detect the stratiform cloud precipitation, it often can found a horizontal extension of the strong echo zone in the vertical structure of clouds, with a height of about in the atmosphere where the temperature near the altitude of 0℃. At the end of the 1940s, Byers first observed this phenomenon, named it with the bright line. Wind profile radar data have high precision and high resolution, compared with the weather radar, it can acquire higher resolution detailed structure of clouds and the full spectrum information of cloud body returns signal.On account of the characteristics of bright band, this paper does research in automatic identification method of bright band. Identifying bright band automatically according to melting layer magnitude of echo intensity and velocity as well as its gradient change trend near the bright band, and also make statistic analysis on various parameters near the bright band. Using the surface precipitation and weather radar to verify the identification algorithm results, and does correction on irrational threshold. The algorithm is applied to a large number of continuous observation data, it is concluded that the success rate is high, the algorithm can identify the bright band effectively. Using the identification results, it can summarize characteristic of various bright band, classify the precipitation cloud based on bright band characteristic, and also can do further research in precipitation cloud.According automatic identification algorithm, this paper makes bright band identification on convection wind profile radar data of Beijing Yanqing region in April to September 2010. There are 18 times bright band exists in precipitation process.1717 times precipitation is continued in a total of 5891 times data, and identify bright band phenomenon 289 times all together. There exist stratiform cloud bright band and mixed bright band in Yanqing region, distribution form of bright band spectral parameter and echo intensity spectral density of different types are different, summarize the differences will in favor of intensive research in stratiform cloud precipitation and mixed precipitation.In addition, Using the boundary wind profiler to detect the bright band appeared in stratiform cloud precipitation process continuously, we can acquired the variation and evolution characteristics of return signal spectrum parameter (power, average Doppler velocity, speed spectral width) and the power spectral density distribution changes with the height nearby the region of bright band. By the boundary wind profiler we can obtain the meticulous structure of precipitation cloud body, and it is important significance in precipitation cloud body microphysical processes research. The ice water transformation process near the bright band area can be seen in the analysis, in the cloud general the surface of snowflake, ice crystals start to melting in the vicinity of-1.3℃, nearly 0.8℃the whole skeleton of snowflake, ice crystal begin breaking into the smaller scale liquid precipitation particles, approximately 3.5℃the ice crystal, snowflake melt to liquid precipitation particles completely. At the same time, in the levels about 300m thickness around 0.8℃can be observed the phenomenon that the echo intensity spectral range stretch suddenly, which reflected that local environment intense temperature decreases caused by precipitation particle ice water transformation may lead to the few detail convection.
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