粤西北一次冬季暴雨和雨转雨夹雪天气的分析
|
摘要
利用常规资料、NCEP 1°×1°再分析资料和连州双偏振雷达资料,对2018年1月8日粤西北暴雨和雨转雨夹雪天气过程进行分析。结果表明:副高增强、南支槽东移和切变线南压是该次暴雨形成的主要机制,西南急流提供动力条件和水汽条件,东北气流加大了风的垂直切变。强冷空气锋面形成低层冷垫,配合850～700 hPa逆温层,上暖下冷的层结有利于雨转雨夹雪。雨夹雪时零速度线呈反S型,并有零度层亮带和"牛眼"型结构特征。双偏振雷达参量Z_(DR)、K_(DP)能够判别出强回波的降水粒子形态,但不能识别雨转雨夹雪的粒子相态的变化。协相关系数能对融化层进行识别,HCL有助于快速定位降水粒子的相态。
With conventional observations, NCEP 1°×1° reanalysis data and data from a dual-polarization weather radar in Lianzhou, a weather process is studied of heavy rain and rain-turned sleet that took place on January 8, 2018. The result is shown as follows. The main mechanisms responsible for this event included a strengthened subtropical high, an east-traveling branch of the westerlies and a south-advancing shear, a southwesterly jet stream provided the dynamic and water vapor conditions and an northeasterly airflow increased the vertical wind shear. A low-level cold "cushion" formed over the frontal surface of intense cold air, and together with an temperature inversion at 850～700 hPa, a stratification that was warmer in the upper layer than in the low layer was favorable for the rain to change to sleet. During the sleet, a contour of zero velocity was shaped like a reversed "S", accompanied with a bright zone of zero degree layer and a structure shaped like the bull's eye. The parameters of Z_(DR) and K_(DP) can identify the morphology of precipitating particles of intense echoes but cannot determine the variation of particle phase during the transition from rain to sleet. Covariance correlation coefficients are able to capture the melting layer and HCL helps locate the phase of precipitating particles rapidly.
With conventional observations, NCEP 1°×1° reanalysis data and data from a dual-polarization weather radar in Lianzhou, a weather process is studied of heavy rain and rain-turned sleet that took place on January 8, 2018. The result is shown as follows. The main mechanisms responsible for this event included a strengthened subtropical high, an east-traveling branch of the westerlies and a south-advancing shear, a southwesterly jet stream provided the dynamic and water vapor conditions and an northeasterly airflow increased the vertical wind shear. A low-level cold "cushion" formed over the frontal surface of intense cold air, and together with an temperature inversion at 850～700 hPa, a stratification that was warmer in the upper layer than in the low layer was favorable for the rain to change to sleet. During the sleet, a contour of zero velocity was shaped like a reversed "S", accompanied with a bright zone of zero degree layer and a structure shaped like the bull's eye. The parameters of Z_(DR) and K_(DP) can identify the morphology of precipitating particles of intense echoes but cannot determine the variation of particle phase during the transition from rain to sleet. Covariance correlation coefficients are able to capture the melting layer and HCL helps locate the phase of precipitating particles rapidly.
引文
[1]苏百兴,段朝霞,梁健.广东省隆冬季节暴雨及个例分析[J].广东气象,2001,23(4):4-6.
[2]李文奕,杨粤红,李永兵,等.一次冬季持续性暴雨过程的诊断分析[J].广东气象,2013,35(5):1-3.
[3]邓文剑,吴乃庚,林良勋,等.2013年冬季广东罕见持续暴雨过程特点及成因[J].气象科技,2015,43(5):276-294.
[4]李厚伟,周静,周义昌,等.一次罕见的冬季暴雨过程分析[J].广东气象,2016,38(2):25-28.
[5]宋晓辉,王咏青,寿绍文,等.冀南一次暴雪天气过程分析[J].气象与环境学报,2010,26(5):1-6.
[6]李欢欢,袁春,黄绍文.一次冬季暴雨转雪天气诊断分析[J].江西科学,2014,32(6):811-814.
[7]郭晓坤,郭喜乐.清远双偏振雷达偏振量产品的初步释用[J].广东气象,2016,38(5):45-48.
[8]夏天竹,徐峰.2013年雷州半岛一次罕见冬季暴雨过程的分析[J].广东气象,2015,37(4):20-23.
[9]王丽荣,汤达章,胡志群,等.多普勒雷达的速度图像特征及其在降雪过程中的应用[J].应用气象学报,2006,17(4):452-458.
[10]周治黔,朱燕,黄世芹,等.2011年贵州两次降雪天气过程的多普勒雷达产品特征分析[J].贵州气象,2012,36(6): 11-15.
[11]郑佳锋,张杰,朱克云,等.双偏振天气雷达测雨误差及水凝物识别分析[J].气象科技,2014,42(3):364-372.
[2]李文奕,杨粤红,李永兵,等.一次冬季持续性暴雨过程的诊断分析[J].广东气象,2013,35(5):1-3.
[3]邓文剑,吴乃庚,林良勋,等.2013年冬季广东罕见持续暴雨过程特点及成因[J].气象科技,2015,43(5):276-294.
[4]李厚伟,周静,周义昌,等.一次罕见的冬季暴雨过程分析[J].广东气象,2016,38(2):25-28.
[5]宋晓辉,王咏青,寿绍文,等.冀南一次暴雪天气过程分析[J].气象与环境学报,2010,26(5):1-6.
[6]李欢欢,袁春,黄绍文.一次冬季暴雨转雪天气诊断分析[J].江西科学,2014,32(6):811-814.
[7]郭晓坤,郭喜乐.清远双偏振雷达偏振量产品的初步释用[J].广东气象,2016,38(5):45-48.
[8]夏天竹,徐峰.2013年雷州半岛一次罕见冬季暴雨过程的分析[J].广东气象,2015,37(4):20-23.
[9]王丽荣,汤达章,胡志群,等.多普勒雷达的速度图像特征及其在降雪过程中的应用[J].应用气象学报,2006,17(4):452-458.
[10]周治黔,朱燕,黄世芹,等.2011年贵州两次降雪天气过程的多普勒雷达产品特征分析[J].贵州气象,2012,36(6): 11-15.
[11]郑佳锋,张杰,朱克云,等.双偏振天气雷达测雨误差及水凝物识别分析[J].气象科技,2014,42(3):364-372.