陈晓欣,俞小鼎,王秀明. 2021. 中国大范围雷暴大风事件(Derechos)研究 部分I:时空分布、环境背景和对流系统形态特征[J]. 气象学报, (0):-, doi:10.11676/qxxb2021.067
中国大范围雷暴大风事件(Derechos)研究 部分I:时空分布、环境背景和对流系统形态特征
Investigation of Derechos in China. Part I: Spatiotemporal Distribution, Environmental characteristics, and Morphology of the Derechos Producing Convective Systems
投稿时间:2021-01-07  修订日期:2021-07-23
DOI:10.11676/qxxb2021.067
中文关键词:  Derechos,下击暴流群,时空分布,环境参数,天气流型,对流系统形态
英文关键词:Derechos, Family of downbursts, Spatial and temporal distribution, Environmental parameters, Weather patterns, Morphology of convective systems
基金项目:国家自然科学基金
作者单位邮编
陈晓欣 中国气象科学研究院 100081
俞小鼎 中国气象局气象干部培训学院 100081
王秀明 中国气象局气象干部培训学院 100081
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中文摘要:
      本文基于2002-2019共18年的高空地面常规观测资料,卫星云图,部分新一代天气雷达单站资料以及2009年以后的全国雷达拼图资料,对发生在中国的大范围雷暴大风事件(Derechos)的时空分布、环境背景和对流系统形态特征进行了分析。结果表明:1)Derechos事件主要发生在华北、华东、江南和华南地区,高频区有明显的季节变化,表现为从春季到夏季先向北移动然后又向南移动;Derechos事件主要发生在3-8月,6月发生频率最高,8月最低;造成Derechos的对流风暴多在正午前后生成,而Derechos事件多开始于午后到前半夜。 2)中国Derechos事件对应的环境参数主要特征:CAPE值分布50%百分位(中位数)为1420J/kg, 明显低于 Evans和Doswell(2001)对美国Derechos事件统计得到的相应值;代表深层垂直风切变的0-6km风矢量差50%百分位数为18.0m/s, 明显高于他们对美国Derechos事件统计得到的相应值;代表对流系统内强下沉气流潜势的DCAPE的50%百分位值为1090J/kg, 与Evans和Doswell(2001)统计的美国Derechos事件的相应值大致相当;中国Derechos事件环境的CAPE值总体上明显低于美国Derechos环境的相应值以及0-6km风矢量差总体上明显高于美国Derechos环境的相应值的原因之一在于中美Derechos季节分布的显著差异, 美国Derechos的相对发生频率在7-8月远高于中国Derechos在同一时段的相对发生频率,那段时间水汽充沛CAPE较高,大气斜压性较弱,0-6km垂直风切变较小。3)采用动态合成分析方法和层次聚类法对Derechos发生时环流背景进行聚类分析表明天气流型配置可分为以下四种:副高边缘型、弱槽型、高空干冷平流强迫型和强槽型,其中强槽型出现的频次最高,高空干冷平流强迫型出现的频次最低。4)如果以Derechos事件中最强对流大风产生时段的对流系统形态进行统计,发现出现频率最高的是飑线;出现频率第二的是多单体风暴簇;产生Derechos事件的对流系统的第三种形态是超级单体或超级单体复合体,伴随长长的阵风锋,所占比例最低。
英文摘要:
      Based on the 36 Derechos in China during 18 years from 2002 to 2019, a study on Derechos spatiotemporal distribution, environmental characteristics, as well as the morphology of the Derechos producing convective systems has been conducted with the proximity sounding, surface observation, satellite images, single Doppler weather radar data, and weather radar mosaics data. The results show: 1) Derechos mainly occur in the eastern half of China except the northeast region, including North China, East China, South China, and regions south of the Yangtze River; The high frequency regions have marked seasonal movement, which is manifested as northward movement during first phase and southward movement during the second phase from spring to summer; Derechos activity has a significant seasonal change, they mainly occur from April to August, with the highest frequency in June and the lowest in August; The convective systems producing the Derechos tend to initiate around noon, while the Derechos themselves tend to occur between mid-afternoon and early midnight. 2) China Derechos can develop and persist in a wide range of instability and shear conditions : 50th percentiles of CAPE is 1420 J/kg, significantly lower than corresponding values given by Evans and Doswell (2001) for Derechos in the United States; The 50th percentiles of the 0-6km vertical shear is 18.0m/s, significantly higher than the corresponding values for Derechos in the United States;The 50th percentiles of the DCAPE is 1090J/kg, in good agreement with the results of Evans and Doswell (2001) for U.S. Derechos; Comparing to U.S. Derechos, one of the important reasons that China Derechos CAPE is lower and 0-6km shear is higher consists in the marked difference in seasonal distribution of Derechos frequency, with much higher frequency of U.S. Derechos in late summer(July-August). 3) Using dynamic synthesis and hierarchical clustering method to cluster the weather patterns during the occurrence of Derechos, it is shown that weather pattern can be divided into the following four types: the subtropical high periphery type, the weak trough type, the high level dry-cold advection forced type and the strong trough type, among which the strong trough type has the highest frequency and the high level dry-cold advection forced type has the lowest frequency. 4)For the period when the maximum wind gust occur, the most frequent convective storm type is squall lines, the second frequent storm type is multi-cell cluster storms and the third frequent storm type is supercell storms.
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