佛山初春冰雹天气层结结构及雷达特征初探
Preliminary Study on Atmospheric Stratification Structure and Radar Characteristics of Hail Weather in Early Spring in Foshan
中文摘要：
采用MICAPS资料、探空资料、雷达资料以及NCEP2.5°×2.5°再分析资料对近2年佛山地区的3次初春（2—3月）冰雹事件进行分析，发现：1）2019年2月21日和2020年3月27日的冰雹过程属于锋面低槽型，2020年3月18日冰雹过程属于高架雷暴型。2）3次过程“上冷下暖”层结结构不明显，不满足?T85越大、冰雹直径越大的规律，但“上干下湿”层结结构明显；2019年2月21日和2020年3月27日的冰雹过程最大热浮力强度大于6 ℃，具备出现大冰雹潜势；满足H－/H＋（冷云和暖云厚度比值）值越大，冰雹直径越大规律。3）雷达图上悬垂回波明显，2019年2月21日和2020年3月27日的冰雹过程还探测到前侧暖湿气流入流缺口和明显中气旋，3月27日冰雹过程高仰角处还探测到明显三体散射长钉；3次过程的VIL值不大，这可能是初春冰雹与夏季冰雹区别之一。
中文关键词：
冰雹，大气层结，雷达回波，初春，佛山
KeyWords：
hail, atmospheric stratification, radar echo, early spring, Foshan
Abstract：
This study used MICAPS data, sounding data, radar data and NCEP2.5×2.5 reanalysis data to analyze the three hail events in Foshan in early spring (February to March) in the past two years. The results suggest: (1) The weather situation of the hails on 21 February 2019 and on 27 March 2020 were both the frontal low trough type, and the weather situation of the hail on 18 March 2020 was the elevated thunderstorm type. (2) The “cold upper and warm lower” stratification structures in the processes of the three hails were not obvious, which does not satisfy the rule that the larger the ?T85, the larger the hail diameter, but the “dry upper and wet lower” stratification structure were obvious; the maximum thermal buoyancy intensity in the processes of the hails on 21 February 2019 and 27 March 2020 were over 6 ℃, which had the potential for large hail and satisfy the rule that the larger the H?/H+ (the ratio of the thickness of cold cloud to warm cloud), the larger the hail diameter. (3) The overhang echoes on the radar chart were obvious. V-shaped gaps and obvious medium cyclones were also detected in the processes of the hails on 21 February 2019 and 27 March 2020, and three-body scattering spikes were obviously detected at high elevation angles in the process of the hail on 27 March; the VIL value of the three processes of the hails were not big, which may be one of the differences between hail in early spring and hail in summer.