| 2013—2017年夏季东北冷涡下东北地区MCS的统计特征 |
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| 引用本文： | 窦慧敏,丁治英,郭春燕,沈新勇,李小凡.2013—2017年夏季东北冷涡下东北地区MCS的统计特征[J].气象科学,2020,40(3):341-353. |
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| 作者姓名： | 窦慧敏 丁治英 郭春燕 沈新勇 李小凡 |
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| 作者单位： | 南京信息工程大学 气象灾害教育部重点实验室/气候与环境变化国际合作联合实验室/气象灾害预报预警与评估协同 创新中心, 南京 210044;温州市气象局, 浙江 温州 325000;南京信息工程大学 气象灾害教育部重点实验室/气候与环境变化国际合作联合实验室/气象灾害预报预警与评估协同 创新中心, 南京 210044;中国气象科学院灾害天气国家重点实验室, 北京 100081;内蒙古气象服务中心, 呼和浩特 010051;浙江大学 地球科学学院, 杭州 310027 |
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| 基金项目： | 国家自然科学基金项目（41530427；41790471；41475039）；中国气象科学研究院灾害天气国家重点实验室研发计划项目（2015LASW-A07）；国家重点研发计划项目（2016YFC0203301）；国家重点基础研究发展计划项目（2015CB453201） |
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| 摘 要： | 利用2013—2017年6—8月FY-2E和FY-2G地球静止卫星相当黑体温度（Black Body Temperature，TBB）资料、NCEP/NCAR再分析资料，对我国夏季东北冷涡下东北地区MCS的分布和活动特征进行了统计分析，结果表明：（1） MCS的活动具有明显的月际变化和日变化特征，6月对流活动最活跃。MCS的主要移向是东、东北和东南，平均移动距离3.99个经纬距。（2） MCS成熟时刻的面积、偏心率和生命史均小于江淮地区以及中国中东部，云顶高度低于江淮地区，整个生命史表现出发展快消亡慢的特征，与江淮地区相反。（3）基于MCS的定义得到的Z标准，对2016—2017年的MCS作了统计分析并与J标准统计得到的MCS进行对比，得出，两种定义下的MCS环境场特征基本一致，主要表现为MCS多生成于500 hPa槽前和槽后，对流层高层MCS位于双急流之间靠近北支急流的辐散区，南侧急流高度在200 hPa，北侧的急流高度在250 hPa。低层，位于低空急流左侧，低涡南侧、东南侧，有较强的水汽和动量输送。槽前生成的MCS南侧中层存在垂直反环流向MCS输送干暖空气与位涡，槽后生成的MCS两侧均有大值位涡向其输送，同时北侧冷干空气的输送使锋区及上升运动加强，更有利于MCS的形成。（4）两种标准下的MCS造成的降水明显不同，在统计强降水方面Z标准要优于J标准。由于Z标准空间与时间尺度较小，统计得到的MCS较多；但同时会遗漏部分相对弱的MCS。
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| 关 键 词： | 中尺度对流系统 统计特征 动态合成分析 双急流 东北地区 |
| 收稿时间： | 2018/7/23 0:00:00 |
Statistical characteristics of MCS in Northeast China under northeast cold vortex in summer from 2013 to 2017 |
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| DOU Huimin,DING Zhiying,GUO Chunyan,SHEN Xinyong,LI Xiaofan.Statistical characteristics of MCS in Northeast China under northeast cold vortex in summer from 2013 to 2017[J].Scientia Meteorologica Sinica,2020,40(3):341-353. |
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| Authors: | DOU Huimin DING Zhiying GUO Chunyan SHEN Xinyong LI Xiaofan |
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| Institution: | Key Laboratory of Meteorological Disaster, Ministry of Education/Joint International Research Laboratory of Climate and Environment Change/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science & Technology, Nanjing 210044, China;Wenzhou Meteorological Bureau, Zhejiang Wenzhou 325000, China;Key Laboratory of Meteorological Disaster, Ministry of Education/Joint International Research Laboratory of Climate and Environment Change/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science & Technology, Nanjing 210044, China;State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing 100081, China;Inner Mongolia Meteorological Service Center, Hohhot 010051, China; School of Earth Sciences, Zhejiang University, Hangzhou 310027, China |
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| Abstract: | Based on the black body temperature data of FY-2E and FY-2G geostationary satellites, the NCEP/NCAR analysis data in summer (from June to August) from 2013 to 2017, and the Jirak''s definition on Mesoscale Convective System (MCS), the statistical characteristics of the distribution and activity characteristics of MCS in Northeast China under northeast cold vortex were analyzed. The results are summarized as follows: (1) the distribution of MCS shows obvious monthly variation and diurnal variation, and it is the most active in June. Eastward, northeastward and southeastward are the three main moving directions for MCSs, with an average moving distance of 3.99 longitude and latitudes. (2) The area of MCS maturing time, the eccentricity and life history of MCS in Northeast China are smaller than those in the Yangtze-Huaihe River Basin and the central and East China, and the height of cloud top is lower than that of the Yangtze-Huaihe River Basin. The characteristic of rapid development and slow extinction is opposite to the Yangtze-Huaihe River Basin. (3) The statistical analysis of MCS from 2016 to 2017, selected by reference to Z. standard according to ZHENG''s definition of MCS is made and compared with the results obtained by J standard based on the Jirak''s definition. It is concluded that the environmental field characteristics of MCS under the two definitions are basically the same. Specifically, most MCSs are generated in front or rear of 500 hPa trough. The upper troposphere MCS is located in the divergence area between the two jet streams, also near the north branch jet. The height of the southern jet stream is 200 hPa, and the northern jet stream height is 250 hPa. At the lower layer, MCS is located on the left side of the low level jet stream and the south and southeast side of the vortex, with strong water vapor and momentum being transported. MCS generated in front of trough is accompanied with dry warm air and potential vorticity being transported from the vertical reverse loop flow at the middle layer in south of the MCS. MCS generated in rear of trough has large potential vorticity in both sides being transported to it. At the same time, the cold and dry air on the north side of the MCS strengthen the frontal area and the upward movement, which is more favorable to the formation of MCS. (4) There are obvious differences in precipitation between MCSs under the two standards. Specifically, Z standard is better than J standard in terms of statistical work of heavy precipitation. More MCSs are obtained due to the smaller space and time scale of Z standard, but some relatively weak MCSs may be omitted. |
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| Keywords: | mesoscale convective system statistical characteristics dynamic synthesis analysis double upper jet Northeast China |
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