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投稿时间:2018-07-04 修订日期:2019-01-17
投稿时间:2018-07-04 修订日期:2019-01-17
中文摘要: 国内利用新一代多普勒天气雷达已经开展了较多冬季天气过程的分析研究,但随着国内雷达网逐渐升级到双线偏振雷达,如何将偏振参量应用于冬季业务预报成为了目前需要解决的问题。利用杭州临安C波段双线偏振雷达观测的2015年12月5日一次降雪过程资料及地面和探空资料,通过提出的基于零度层亮带识别的降雪相态识别方法和降雪累计时间统计方法,分析了雷达参量、零度层亮带的时空演变及统计的降雪累计时间分布特征,并与地面和探空资料对比,探索了双线偏振雷达在冬季降雪预报中的优势。结果表明:(1)冬季降水相比夏季连续性降水回波强度偏弱;雨、雪的差分反射率因子、相关系数差别不大。(2)零度层亮带在某些方位并不是水平的,大多数情况下为偏离雷达站的不规则环状或者线状,且某些时刻还有垂直零度层亮带存在。(3)降雪累计时间分布与实际降雪厚度分布基本一致,统计方法为地区降雪厚度的估测提供了可能。(4)零度层亮带的演变与地面和探空温度的空间、时间变化一致,相比单极化雷达使用双线偏振雷达观测零度层亮带更加可靠。
Abstract:Depending on the New Generation Doppler Weather Radar, many studies on winter weather processes have been carried out in China. However, as the radar network in China is gradually upgraded to the dual-polarization radar, how to apply the polarization parameters to winter forecasting operation has become an important issue to be solved at present. Using the identification method of hydrometeor and statistical method of snowfall accumulation time based on bright band identification and the observation data of a snowfall process detected by the C-band dual-polarization radar in Linan on 5 December 2015, this study analyzes the spatio-temporal evolution characteristics of radar parameters, bright band and the distribution of snowfall accumulation time associated, and compares the analysis results with the ground and radiosonde data, preliminarily exploring the advantages of the dual-polarization radar in winter snow forecast. The results indicate that: (1) The echo strength of winter rainfall is weaker than that of continuous precipitation in summer. The differential reflectivity factor and the correlation coefficient between rain and snow is not significant, making it difficult to identify the winter hydrometeor with the fuzzy logic method. (2) The bright band in this process is an irregular ring or linear shape that deviates from the radar station. It is not horizontal at some spots, and sometimes there is a vertical bright band. (3) The distribution of snowfall accumulation time, obtained by the proposed method of hydrometeor identification and the method of snowfall accumulation time statistics, is basically consistent with the observed snow depth distribution. These methods provide a possibility for estimating snow depth in some regions. (4) The evolution of bright band is corresponding with the spatio-temporal changes of the ground and radiosonde temperature. Compared with the single-polarization radar, it’s more reliable to identify bright band using the dualpolarization radar.
文章编号: 中图分类号: 文献标志码:
基金项目:浙江省重大科技专项(2017C03035)资助
作者 | 单位 |
魏玮 | 成都信息工程大学,成都 610225 中国气象科学研究院灾害天气国家重点实验室,北京 100081 |
刘黎平 | 中国气象科学研究院灾害天气国家重点实验室,北京 100081 |
吴翀 | 中国气象科学研究院灾害天气国家重点实验室,北京 100081 |
王红艳 | 中国气象科学研究院灾害天气国家重点实验室,北京 100081 |
周淼 | 杭州市气象局,杭州 310000 |
引用文本:
魏玮,刘黎平,吴翀,王红艳,周淼,2019.杭州“12·05”降雪天气过程的偏振雷达观测分析[J].气象,45(9):1248-1261.
WEI Wei,LIU Liping,WU Chong,WANG Hongyan,ZHOU Miao,2019.Analysis of Dual-Polarization Radar Observation During the 5 December 2015 Snowfall Process in Hangzhou[J].Meteor Mon,45(9):1248-1261.
魏玮,刘黎平,吴翀,王红艳,周淼,2019.杭州“12·05”降雪天气过程的偏振雷达观测分析[J].气象,45(9):1248-1261.
WEI Wei,LIU Liping,WU Chong,WANG Hongyan,ZHOU Miao,2019.Analysis of Dual-Polarization Radar Observation During the 5 December 2015 Snowfall Process in Hangzhou[J].Meteor Mon,45(9):1248-1261.