摘要
利用黄南C波段双偏振雷达探测资料对2023年8月3日青海省黄南州河南县的短时强降水过程从雷达强度、速度、偏振和定量降水估计产品进行特征分析,结果表明:(1)河南地区在降水开始前CR在50 dBZ以上,配合VIL在10 kg/m^(2)左右,TOPS在10 km左右,HT在2 km左右,降水开始后回波强度有所增强或维持在50 dBZ,可考虑出现短时强降水。(2)径向速度辐合维持时间段对应降水最强时段,速度图上出现零速度线“弓形”特征可以作为降水持续时间较长的标志。(3)VWP产品上风场由不连续变得连续,对短时强降水的出现有很好的指示意义。(4)短时强降水开始前30~60 min,CC值大于0.97表明降水相态为纯雨,大值Z_(c)对应大值Z_(DR)和K_(DP)表明雨滴尺寸和雨滴粒子密度较大,容易产生超过20 mm/h的短时强降水。(5)实况降水地区离雷达距离越近,则OHP产品的降水落区与实况位置越接近,但在降水量的估计上大于实况降水量。THP产品降水落区和降水量均与实况有一定偏差,有待于进一步分析总结,凝练出有参考意义的相应指标。文章分析结果可为类似短时临近天气预报提供参考依据,具有较好的业务应用价值。
Based on Huangnan C-band dual polarization radar detection data on August 3,2023,the short-term heavy precipitation process in Henan County was analyzed through characteristics from the radar intensity products,velocity products,polarization products and quantitative precipitation estimated product.The results show that:(1)In Henan region before the precipitation,the CR was above 50dBZ,with the VIL around 10kg/m^(2),the TOPS around 10km,and the HT around 2km.After the precipitation,the echo intensity either increased or was maintained at 50dBZ,which was considered indicative of short-term heavy rainfall.(2)The convergence zone maintenance period of the radial velocity corresponds to the strongest period of the precipitation.The“bow”feature of the zero velocity line on the velocity chart could be used as a sign of the long duration of the precipitation.(3)The upper wind field of VWP products changed from discontinuous to continuous,which had a good indicator significance for the occurrence of short-term heavy precipitation.(4)30-60 minutes before the onset of short-time heavy precipitation,a CC value greater than 0.97 indicated that the precipitation phase was pure rain,and large value of Zc corresponding to large value of ZDR and KDP indicated that the raindrops size and raindrop particle density were large,which made it likely to produce short-time heavy precipitation exceeding 20mm/h.(5)The nearer the actual precipitation region to the radar,the more closely the precipitation area depicted in the OHP product aligns with the actual location,but the precipitation estimate was greater than the actual precipitation.The precipitation area and amount of THP products have certain deviations from the actual situation,and further analysis and summary are needed to condense corresponding indicators with reference significance.The analysis results of this paper can provide a reference for similar short-term nowcasting and have good business application value.
作者
廖淑君
李静
李剑婕
王成雄
曹迪
巨海晨
Liao Shujun;Li Jing;Li Jianjie;Wang Chengxiong;Cao Di;Ju Haichen(Qinghai Meteorological Observatory,Xining 810001,China)
出处
《青海科技》
2024年第4期129-133,共5页
Qinghai Science and Technology
基金
青海省气象台自立气象科学技术研究项目(STZL2023-01)
青海省气象局纳入省局管理自筹项目(QXZC2023-07)。
关键词
双偏振雷达
河南县
短时强降水
Dual-polarimetric radar
Henan County
Short-term heavy precipitation
