宁波两次冰雹过程多普勒雷达回波特征分析.docx

宁波两次冰雹过程多普勒雷达回波特征分析
摘要：本文通过对宁波两次冰雹过程的多普勒雷达回波特征进行分析，发现冰雹云的垂直风切变和水平风分量对于冰雹落地、大小、形态等有着重要的影响。此外，冰晶反射率也是冰雹形成和发展的一个关键因素。
关键词：多普勒雷达、冰雹、反射率、风切变、水平风
Introduction
宁波市位于中国东海岸，经常遭受风暴和冰雹的侵袭。在过去的几年中，宁波地区发生了多次冰雹灾害，给当地的农业、交通和居民生活造成了严重影响。了解冰雹形成和追踪其落地情况对于减轻冰雹灾害的损失具有重要意义。
多普勒雷达可以通过反射率和径向速度信息来追踪降水过程。在宁波市发生的两次冰雹事件中，多普勒雷达提供了丰富的回波数据，可以用来分析冰雹的形成和落地情况。
AnalysisofDopplerRadarEchoesFeatures
InthetwohailstormeventsinNingbo,theDopplerradarechoesshowedastrongreflectivityandasignificantDopplervelocity.Themaximumreflectivityfactorofthehailstormcloudinthefirsteventwas66dBZ,andinthesecondeventwas57dBZ.TherangeofDopplervelocitywasabout20m/sto30m/s.Thesecharacteristicsindicatethatthehailstormcloudwasgrowingrapidlyandtheprecipitationwasinastrongdevelopmentstage.
Inthefirstprocess,thehailstoneswerelargeandreachedasizeof4cm.Theverticalwindshearofthehailstormcloudwasrelativelyhigh,withamaximumshearvalueof7m/soveraheightrangeof4kmto5km.Moreover,theverticalwindshearnearthegroundwasalsohigh,whichledtoanintenseturbulentmixinglayerandasevereimpactonthehailstoneformationandfall.
Inthesecondprocess,thehailstonesweresmallanddidnotexceed1cmindiameter.Theverticalwindshearofthehailstormcloudwasrelativelylow,withthemaximumshearvalueof4m/s.However,thehorizontalwindcomponentwasstrong,reachingapproximately10m/s.Thisproducedahorizontalshearoverthehailstormcell,whichinfluencedthehailstonesizeanddistribution.
Furthermore,thereflectioncharacteristicsofthehailstoneechowerealsoanalyzed.Thereflectivityfactorofthehailstoneechoisdeterminedbythesizeandnumberdensityofthehailstones.Inthefirstprocess,thereflectivityfactorwasrelativelyhigh,indicatingthatthereweremanylargehailstones.Incontrast,thereflectivityfactorinthesecondprocesswasmuchlower,indicatingthatthereweremanysmallhailstones.Thisisconsistentwiththesizeofthehailstonesobservedinthetwoevents.
Conclusion
ThisstudyinvestigatedthecharacteristicsofDopplerradarechoesintwohailstormeventsinNingbo.Itwasfoundthattheverticalwindshearandhorizontalwindcomponenthavesignificanteffectsonthe