摘要
针对2007年湖北省在鄂东地区组织的4次外场试验作业,应用对流云人工增雨雷达效果分析软件选择对比云的方法,对催化目标云和对比云的多普勒天气雷达参数的变化特征进行了对比分析,并应用X波段双偏振雷达资料、FY2C卫星资料、闪电定位仪、加密雨量站等资料,对催化效果进行了初步分析。结果显示,催化后,目标云发生了比较明显的变化,回波强度、强回波面积、回波顶高、液态含水量、强回波高度等催化后均增大,约半小时内都能达到最强;而对比云增大率比目标云小,或者没有增大,目标云生命期比对比云长。双偏振因子线性退极化比极小值变小,极小值区域面积变大;较大零延迟相关系数的面积也有所增大。FY2C卫星反演云参数不能有效地检验强对流云的催化效果,而对于层状云,云顶高度上升,云顶温度降低,过冷层厚度增大,有效粒子半径维持大粒子水平,云顶黑体亮温下降。闪电频数在催化后也有所增多,主要发生在催化后约半小时内。强回波中心对应的分钟雨强在催化后半小时内达到最高,降雨主要集中在从约第10分钟开始的20分钟内,与对比云相比,目标云降水时间长,降水强度大。
By using the data observed by Doppler weather radar, dual-linear polarization and entire-phase-parameter weather radar (on 3 cm wave-band), lightning location net and precipitation observation stations, the effect of 4 seeding experiments in eastern Hubei in 2007 are analyzed. The results show that there are increasing changes of the Doppler echo characteristics of the target cloud in short time after seeding, including the intensity and area of strong echoes, echo tops, the value and the area of larger VIL, these factors reach the maximum in 25 min. Compared with the contrast cloud, the enlargement rate of seeded cloud is large. The FY2C data cannot reflect the seeding effect on convective cloud, but on stratus cloud, the cloud-top height rises while the cloud top temperature reduces, super-cooled cloud thickness increases, the effective particle radius maintains the big granule level and the cloud top brightness temperature drops. The dual-polariza- tion factors including Ldr and phv(area of large value), the frequency (maximum appearing at 18th minute) and intensity of lightning all vary. Main rainfall period is centralized in half an hour from the 10th minute, and the rainfall intensity and duration of seeded cloud are more than those of contrast cloud.
出处
《气象》
CSCD
北大核心
2009年第8期70-75,I0004,共7页
Meteorological Monthly
关键词
人工增雨
多普勒天气雷达
闪电定位
自动雨量站
artificial precipitation enhancement Doppler weather radar lightning locationautomatic rainfall observing station