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投稿时间：2011-08-16 修订日期：2012-03-18
投稿时间：2011-08-16 修订日期：2012-03-18
中文摘要: 利用新一代天气雷达基数据资料和天津三次不同类型降水天气过程的降水量资料，采用变分校准方法，以校准区域内所有雨量计校准雷达得到的估测降水场作为“真值场”，对比分析14种不同密度雨量计网校准雷达估测降水的效果，并对雨量计网中单个雨量计站点对校准雷达的贡献进行试验分析。结果表明:（1）参加校准的雨量计密度较小时，雷达估测降水的误差较大，估测效果不好；随校准雨量计密度的不断加大，雷达估测降水的偏差明显减小、估测精度不断提高并逐渐趋于稳定。（2）校准不同类型降水需要的雨量计密度不同，这与降水的性质有关；当校准雷达估测降水的效果与“真值场”的相当时，所需的雨量计密度为121 km2·部-1。（3）在雨量计校准网中任意增加降水量不为零的站点，会在增加的站点周围出现估测偏差（高估或低估），偏差的大小与站点降水量相对于其周围雨量计平均值的大小有关、偏差的影响范围则与站点周围雨量计的分布密度有关。（4）任意增大（减小）雨量计校准网中单个站点的降水量会使雷达对站点周围降水的估计偏高（偏低），高（低）估的程度及影响范围与站点降水量增大（减小）的多少及站点周围雨量计分布密度有关，而与降水类型及降水随时间的演变无关。
Abstract:Based on the three different types of precipitation data of Tianjin and Doppler radar observational data, using the radar rainfall estimation grid point field derived from the all valid raingauge calibration as a “true” value, the accuracy of radar rainfall estimates by 14 different raingauge density calibrations is studied, and the contribution of one raingauge to radar rainfall estimates is also analyzed. The conclusion can be drawn as follows: (1) Radar rainfall estimation error is bigger when the raingauge calibration density is lower, then estimation results are not satisfactory. However the estimation accuracy of radar is continuously improved and estimation error is significantly reduced, with the raingauge calibration density increased. (2) Calibration on different types of precipitation needs different raingauge densities, which is related to the nature of precipitation. When the precision of radar estimation is equal to the precision of the “true” value, the raingauge maximum density on calibration radar is required to be one raingauge per 121 km2. (3) Any increased raingauge site, whose precipitation is zero, has no impacts on radar rainfall estimation. When it is not zero, the estimation error would appear around the site (over or under estimate), and the deviation of estimation is closely related to the average precipitation and the distribution of raingauge density around the raingauge site. (4) When randomly increased (decreased) precipitation of single raingauge site, the radar would be over or under estimated the precipitation around the raingauge site, and the degree of over or under estimates and the area of bias are related to the density of the surrounding raingauges and the changes in the size of precipitation, which was unrelated to the type of precipitation and either unrelated to the variation of precipitation over time.
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基金项目:公益性行业(气象)科研专项(GYHY201106046)资助
| Author Name | Affiliation |
| DONG Gaohong | Tianjin Meteorological Observatory， Tianjin 300074 |
| LIU Liping | State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing 100081 |
引用文本：
东高红,刘黎平,2012.雨量计密度对校准雷达估测降水的影响及单点对校准的贡献[J].气象,38(9):1042-1052.
DONG Gaohong,LIU Liping,2012.The Contrast Analysis of Raingauge Density Calibration and Impacts of Single Raingauge on Radar Rainfall Estimates[J].Meteor Mon,38(9):1042-1052.
东高红,刘黎平,2012.雨量计密度对校准雷达估测降水的影响及单点对校准的贡献[J].气象,38(9):1042-1052.
DONG Gaohong,LIU Liping,2012.The Contrast Analysis of Raingauge Density Calibration and Impacts of Single Raingauge on Radar Rainfall Estimates[J].Meteor Mon,38(9):1042-1052.