摘要
基于长沙黄花机场阵列天气雷达高时空分辨率探测资料和机场区域4个自动气象站逐分钟降水观测资料,对2018年5月20日与8月1日发生在机场附近的2次对流过程的回波特征演变进行分析,并利用单位面积等效势能分别对2次天气过程进行分析。结果表明:阵列天气雷达可为短时强降水过程的研究提供精细数据。2018年8月1日为一次短时强对流过程,近地面无明显辐合辐散现象,单位面积等效势能的释放比远小于30%,未形成明显下沉气流。2018年5月20日的对流过程产生了一次局地下沉气流,地面最大风速11.6 m·s^-1,单位面积等效势能释放比大于30%;风暴体在0℃层附近开始发展,单体间的碰并增长形成了新风暴并加速了新风暴的发展;回波的中层径向辐合和近地面辐散特征与地面自动气象站风速风向变化时间一致;自动气象站的露点温度与气压的升高,对风暴体的下沉气流有一定指示作用;利用单位面积等效势能释放比指标,阵列天气雷达可在地面风速达最大前13 min给出预警信息,提高对短时小尺度天气系统例如下击暴流的监测预警能力。
Based on the high spatial and temporal resolution detection data of the array weather radar(AWR)at Changsha Huanghua Airport,and the minutely precipitation observation data of four regional automatic weather stations,the evolution of echo characteristics of two convective events occurring near the airport on 20 May 2018 and 1 August 2018 were analyzed,and the effective potential energy per unit area was used to analyze the two events.The results show that the AWR could provide fine data for the study on the development of the short-time severe precipitation.The convective process on 1 August 2018 was a short-term strong convection process without a significant downdraft,and there was no significant convergence and divergence near the ground,and the effective potential energy release ratio per unit area was far less than 30%.The convective process on 20 May 2018 produced a local downdraft with the surface maximum wind speed of 11.6 m·s^-1,and the release ratio of equivalent potential energy per unit area was over 30%.The storm began to develop near the 0℃layer of the atmosphere and formed several storm cells.The coalescence growth of the storm cells led to form a new storm and accelerated the development of the new storm.The mid-level radial convergence and near-surface divergence of the echo were consistent with the wind speed and wind direction changes of the surface automatic meteorological station.The increases of the dew point temperature and pressure from automatic weather station had a certain indicative effect on the downdraft of storm.The AWR provided the warning information of 13 minutes before the surface wind speed reaching its maximum value,and improved the monitoring and early warning on short-time small-scale weather systems such as downbursts by analyzing the effective potential energy release ratio per unit area.
作者
李方平
马舒庆
杨玲
甄小琼
吕寺炜
LI Fangping;MA Shuqing;YANG Ling;ZHEN Xiaoqiong;Lü Siwei(College of Electronic Engineering,Chengdu University of Information Technology,Chengdu 610225,China;Meteorological Observation Center of CMA,Beijing 100081,China;Institute of Atmospheric Physics,China Academy of Science,Beijing 100029,China;CMA Key Laboratory of Atmospheric Sounding,Chengdu 610225,China;Rayshon Technology Company,Limited,Beijing 100089,China)
出处
《干旱气象》
2020年第6期947-954,共8页
Journal of Arid Meteorology
基金
国家自然科学基金国家重大科研仪器研制(部委推荐)项目(31727901)资助。
