周璇,孙继松,张琳娜,陈官军. 2020. 华北地区持续性极端暴雨过程的分类特征[J]. 气象学报, (0):-, doi:10.11676/qxxb2020.052
华北地区持续性极端暴雨过程的分类特征
Classification characteristics of continuous extreme rainfall events in North China
投稿时间:2019-11-13  修订日期:2020-04-20
DOI:10.11676/qxxb2020.052
中文关键词:  华北地区 持续性极端暴雨 分类 环流特征
英文关键词:North China, continuous extreme rainfall events, classification, atmospheric circulation characteristics
基金项目:国家科技支撑计划(2015BAC03B00)
作者单位E-mail
周璇 中国气象科学研究院灾害天气国家重点实验室北京市气象台 zhouxuan07@126.com 
孙继松 中国气象科学研究院灾害天气国家重点实验室 sunjs@cma.gov.cn 
张琳娜 北京市气象台 zln_zhang@sina.com 
陈官军 中国人民解放军96941部队 aiolya_gj@163.com 
摘要点击次数: 327
全文下载次数: 392
中文摘要:
      摘 要 [资料和方法]利用1960-2015年日降水资料,本文筛选出华北地区56次极端暴雨过程。基于距平相关系数的客观聚类分析方法和天气学检验,将它们进行分类,并使用NCEP(2.50x2.50)再分析资进行分类合成,[目的]对比分析不同环流背景下华北持续性极端暴雨过程的基本特征。[结果和结论]结果表明,这些极端暴雨事件按照环流背景可分为经向型、纬向型、减弱的登陆热带气旋型和初夏型四类。它们一般都与不同天气系统配置结构下的锋面动力学过程有关,由于锋面结构特征、环境大气层结状态以及与低空急流有关的暖湿输送通道和强度不同,造成不同环流特征背景下,暴雨日的高频站点与过程平均累计降水量在空间分布上的关系存在差异。(1)纬向型持续性暴雨对应的锋区强度显著强于经向型暴雨,但是其对应的层结稳定度与整个夏季状态相当(),而经向型暴雨存在弱的层结不稳定异常,这表明,纬向型持续性暴雨的对流活动一般不如经向型剧烈,持续性锋面降水特征更清晰,造成站点上日降水量超过50mm的最大频次明显低于经向型暴雨过程,但是过程累计平均最大降雨量却比经向型更大。(2)从水汽输送通道来看,源于西太平洋副热带高压南侧的水汽通道只在纬向型环流主导下的华北持续性区域极端暴雨过程中起由主导作用。初夏极端暴雨以及减弱的登陆热带气旋与西风带系统相互作用造成的华北极端暴雨过程中,活跃的印度季风造成25°N以南异常强盛的纬向型低空西南气流携带充沛的水汽,穿过中南半岛后以西南低空急流或者通过减弱的登陆热带气旋“中转”,是这两类暴雨区的主要水汽供应源;经向型环流背景下的水汽输送也与这支源于青藏高原南侧的西风气流异常有关。这可能是华北地区夏季降水与印度季风降水的相关性显著强于我国东部其他地区的主要原因;(3)减弱的登陆热带气旋与西风带系统相互作用造成的华北极端暴雨过程同样属于经向型环流主导下的暴雨过程,但是,更充沛的水汽输送、更强的上升运动和更深厚的不稳定大气层结状态是它比一般的经向型环流背景下的华北暴雨强度更大的直接原因;此外,中高纬度弱冷空气侵入对减弱的登陆热带气旋顶部形成持续性区域极端暴雨过程是非常重要的。
英文摘要:
      Abstract According to the daily precipitation data provided by China Meteorological Administration from 1960 to 2015, 56 continuous extreme rainfall events in North China were filtered in this paper. Using the objective clustering analysis method based on the anomaly correlation coefficient and synoptic appraisal, these events were classified. Furthermore, the NCEP reanalysis data (2.50x2.50) was used to classify and synthesize the synoptic characteristics. Results showed that the continuous extreme rainfall event patterns in North China were warp-wise?type, across-warp type, reducing landed tropical?cyclone?type and early summer type. The four types were generally related to the frontal dynamics process under different weather configurations. However, due to the differences in frontal structural features, the environmental atmospheric stratification state, and the warm and humid transport channels associated with low-level jets, the spatial distributions of high-frequency meteorological?stations with daily precipitation ≥50mm and the average cumulative precipitation showed different patterns. (1) The intensity of the frontal zone corresponding to the continuous extreme rainfall event of across-warp type was significantly stronger than that corresponding to the event of warp-wise type. However, the stratification stability for the across-warp type was similar with the climate state of summer (, while there was a weak-instability in the warp-wise type. As a result, the convective activity in the extreme rainfall event of across-warp type was generally less violent than in that of warp-wise type, and it exhibited a clearer frontal precipitation characteristics with continuous rainfall , that is, the frequency of daily precipitation ≥50 mm in the across-warp type was significantly lower than that of in the warp-wise, while the across-warp type had more cumulative precipitation. (2) The water vapor transport channel, which was derived from the south side of the Western Pacific Subtropical High, only played a leading role in the across-warp type. In the early summer type and reducing landed tropical?cyclone?type, the active Indian monsoon caused a strong latitudinal low-level southwesterly airflow anomaly to the south of 25°N, which became the main source of water vapor after traveled through the Indo-China Peninsula or was "transferred" by tropical cyclone. In addition, the water vapor transport of the warp-wise type was also related to this westerly airflow anomaly originating from the south side of the Qinghai-Tibet Plateau. This factor might be the main reason why the summer precipitation in North China had a stronger correlation with the Indian monsoon precipitation than that in other parts of eastern China. (3) Similar with the warp-wise type, the reducing landed tropical?cyclone?type was also dominated by the meridional atmospheric circulation. However, as a result of more water vapor transport, greater vertical?velocity and deeper unstable atmospheric state, the precipitation intensity of the tropical cyclone type was more concentrated. In addition, for the extreme rainfall events located at the northern ridge of reducing landed tropical?cyclones, the weak cold air invasion generated from higher altitudes was significantly dynamic effective.
查看全文   查看/发表评论  下载PDF阅读器
分享按钮