对甘肃中部局地最大冰雹直径识别的对比分析

以3D-Barnes方案插值的新一代天气雷达反射率因子等高平面资料,用垂直累积液态含水量(vertically in-tegrated liquid water content,简称VIL)的理论模式计算单体的VIL,用VIL与单体顶高度之比计算单体的垂直累积液态含水量密度(vertically integrated liquid water content density,简称VILD),利用MAX函数逐个提取雹云单体在降雹过程中的最大VIL和VILD(分别简称VILmax和VILDmax),采用统计和回归处理技术,利用2004-2006年的5~8月甘肃中部54例局地冰雹单体个例,对单体VILmax和VILDmax与地面最大降雹区的位置、地面最大冰雹直径(简称Rmax)之间的相关性以及对Rmax的识别效果等进行了对比分析。结果表明:①从总体上看,单体VILmax和VILDmax与地面最大降雹区的位置基本保持一致,且Rmax越大,一致性越好,但VILDmax与地面最大降雹区的位置比VILmax更接近。②VILmax和VILDmax在总体上与Rmax之间存在一定的正相关关系,但VILDmax与Rmax之间的相关性比VILmax更好。③相同的识别因子,用不同回归类型所建立的回归方程有所不同,但从回代结果的效果比较,VILmax和VILDmax均是用二次函数关系建立的与Rmax之间的回归方程的效果最好;不同的识别因子,用相同的回归类型所建立的回归方程自变量前的系数也存在差异,但用VILDmax作为识别因子的识别效果比用VILmax更好。

Contrastive Analysis on the Discrimination of Local Maximal Hailstone Diameter in Central Gansu Province

Based on constant altitude plan data like reflectivity factor,collected by a new weather radar interpolated with 3D-Barnes scheme,in this paper the vertically integrated liquid water content(VIL) and vertically integrated liquid water content density(VILD) of hailstone cells are calculated with the theoretical model,ration of VIL and upright height of hailstone cells,and the maximums of VIL(VILmax) and VILD(VILDmax) are identified using MAX function.Based on the data of 54 cases of local hailstone fall in central Gansu Province during the period from May to August of 2004-2006,the correlations between the VILmax or VILDmax and the geographical location of the regions with the maximal hailstone fall or the maximal diameter of hailstone cell on the ground as well as the Rmax discrimination are contrastively analyzed.The results show that,as a whole,the geographical locations of the regions with the maximal hailstone fall accord basically with the VILmax or VILDmax,and the consistency is increased with the increase of Rmax,but the correlation with VILDmax is higher than that with VILmax.There is a certain positive correlation between the VILmax or VILDmax and the Rmax,but the correlation between the VILDmax and the Rmax is higher than that between the VILmax and the Rmax.