南半球大气环流对华南前汛期降雨影响初探

Multiparameter Radar Application in Rainfall Rate Estimation in the Presence of Hail

利用南半球海平面气压场格点资料，通过差值场和相关分析，研究了南半球大气环流对华南前汛期降雨的影响。结论指出，无论是同期还是前期，华南前汛期多雨年和少雨年所对应的南半球大气环流系统基本呈反相，两者之间存在密切关系。还就澳大利亚高压、马斯克林高压、南美对流活跃区等对华南前汛期降雨影响的可能机理进行了初步分析。首次讨论了澳大利亚高压强度与影响华南的南海西南季风强度之间反相关的有趣事实。

Based on multiparameter radar (dual polarization,dual wavelength,and Doppler)observations of early Summer severe storm accompanied by hail,reflectivity Z h ,specific differential phase K dp at S band and X band specific attenuation A x were applied to estimate rainfall rates.The estimates from radar parameters were compared with groundbased raingage measurements.The results show that both R K dp and R A x relations were in good agreement with the raingage data,that is,less than 10% difference in the rainfall accumulations.The R Z h relation produced similar results only when Z h was truncated at 55dBz.This study demonstrates the potential of K dp for estimating rainfall rates in convective rainstorms with rain hail mixtures.