冷锋云系的多普勒雷达反射率因子特征总结

目的]总结冷锋云系的多普勒雷达反射率因子特征。方法]从反射率因子特征上来研究冷锋云系,利用2002～2007年哈尔滨新一代天气雷达资料,总结了冷锋云系的反射率因子特征。结果]冷锋所产生的云总体上说呈带状,但其间云体有间隙,且强度分布不均匀;多数移动快的冷锋为长而窄的回波带,移动缓慢的冷锋或弱冷锋,则呈宽广的片状或片絮状回波;面积大的冷锋云系通过测站基本都可以分析出径向速度由西北风转为西南风;随着月份的不同,反射率因子特征也有很大的变化。在冬季,冷锋云表现为层状云,反射率因子特征非常弱,一般面积较大,呈片状,但结构松散,回波间有间隙,其中夹杂着几块比较强的回波;在冷锋两侧易产生强度大的对流单体回波,一般会随着整体云带移动,移速、移向基本一致;干冷锋移过时,易局地产生强对流,以对流云为主,回波面积较小,一般从径向速度图中分析不出风向转变,但单体的强度特征明显,一般有＂三体散射＂、＂旁瓣＂、＂弱回波区＂特征,具有超级单体的特征。结论]该研究为多普勒雷达在黑龙江省监测灾害天气的应用上起到了积极作用。

The Characteristics of the Cold Front Cloud in Doppler Redar Reflectivity Factor

Objective] The aim was to summarize the characteristics of reflectivity factor of Doppler radar of the cold front cloud system.Method] Judging from the characteristics of reflectivity factor by dint of the new generation doppler radar in Harbin from 2002 to 2007,the feature of the reflectivity factor of the clod front cloud system was summarized.Result] The cloud formed by the cold front was in banded form in general.However,there was void in the cloud and its intensity was uneven.Most fast moving cold front was long and narrow banded echo and basically the radial velocity turned from northwest wind to southwest.With the changes of month,the feature of the reflectivity factor also changed.In winter,the cold front cloud was in layer form.The feature of the reflectivity factor was weak and in large area.However,the structure was loose and there was space in the echo.Among them,there were several strong echoes.Strong convection cell echo formed in the two sides of the cold front,and it moved with the entire cloud belt.When the dry cold front moved,regional strong convective current formed,mainly by convective cloud and small echo area.Generally,the changes of the wind direction can not be expounded from the longitude speed.However,the intensity of the cell echo was distinct,"three-body scattering","side lobe echo",and "weak echo region",as well as feature of supercell.Conclusion] The study provided active role for the application of Doppler radar in the surveillance of weather in Heilongjiang Province.