设为首页
加入收藏
Statistical Characteristics of Isolated Convection in the Jianghuai Region
-
摘要: 孤立对流云是江淮地区重要的降水云系，通过分析江淮地区2013—2016年6—9月的多普勒天气雷达数据，统计得到664个对流云，其中孤立对流云196个，占江淮地区对流云发生频率的29.5%，7月和8月是江淮地区孤立对流云的高发期，6月相对较少，9月最少，同时12：00（北京时，下同）—18：00是孤立对流云的高发时段，05：00—07：00孤立对流云发生频率最低。针对2013年7月20日安徽定远出现的孤立对流云个例，综合分析多普勒天气雷达和C波段连续波雷达探测资料，发现此次暖区孤立对流云内部强反射率因子中心交替生成，导致内部反射率因子呈强弱交替出现的波状结构，沿着移动方向由弱到强，降水粒子下落速度与之对应，降水粒子最大落速出现在孤立对流云中下部的强反射率因子区域，速度超过10 m·s-1。Abstract: Isolated convective clouds are important precipitation cloud systems in the Jianghuai Region. Based on the analysis of radar data from June to September during 2013-2016, a total of 664 convective clouds are identified, in which 196 are isolated convective clouds. It is found that isolated convective clouds account for 29.5% of the total convective clouds in the Jianghuai Region. July and August are the high incidence periods of isolated convective clouds, while isolated convective clouds occur less in June and the frequency of occurrence is the least in September. At the same time, the high incidence time of isolated convective clouds is from 1200 BT to 1800 BT, and the lowest incidence time is from 0500 BT to 0700 BT. It is found that the circulation background has a great influence on the isolated convective clouds in this area. July-August is the high incidence of isolated convective clouds in the Jianghuai Region, which is mainly related to the circulation background during this period. The Jianghuai Region is often in the periphery of the subtropical anticyclone in July-August due to the high temperature and the increase of local unstable energy, and it often leads to the occurrence of local scattered convective clouds. In addition, in view of the isolated convective clouds at Dingyuan, Anhui Province on 20 July 2013, the Doppler radar and the C-band Frequency Modulation Continuous Wave radar detection data are comprehensively analyzed. It is found that there is a strong echo center alternately generated in the isolated convective clouds in the warm area, resulting in the wave structure of the internal echo reflectivity with the intensity distribution from weak to strong along the moving direction. In the vertical direction, the radar reflectivity factor increases at first and then decreases from top to bottom. The falling velocity intensity of precipitation particles correspond to it. The maximum falling velocity of precipitation particles appears in the strong echo region in the middle and lower parts of isolated convective clouds, and the velocity is over 10 m·s-1.
-
图 1 雷达位置及研究区域
(×为多普勒天气雷达位置，Δ为C波段连续波雷达位置)
Fig. 1 The location of radars and the target area
(× is the location of Doppler radar, Δ is the location of C-FMCW)
图 2 2013—2016年6—9月江淮地区孤立对流云发生频次
Fig. 2 The frequency of isolated convective clouds in the Jianghuai Region from Jun to Sep during 2013-2016
图 3 2013年7月31日08:00 500 hPa高度场(等值线，单位：gpm)和850 hPa风场(风羽)
Fig. 3 500 hPa height (the contour, unit:gpm) and 850 hPa wind (the barb) at 0800 BT 31 Jul 2013
图 4 2013年7月20日08:00 500 hPa高度场(等值线，单位：gpm)和850 hPa风场(风羽)
Fig. 4 500 hPa height (the contour, unit:gpm) and 850 hPa wind (the barb) at 0800 BT 20 Jul 2013
图 5 2013年7月20日10:00—13:00定远站降水量
Fig. 5 Rainfall amount at Dingyun Station from 1000 BT to 1300 BT on 20 Jul 2013
图 7 2013年7月20日定远站组合反射率因子
Fig. 7 Superimposition of radar reflectivity at Dingyuan Station on 20 Jul 2013
图 8 2013年7月20日定远孤立对流云垂直结构(a)反射率因子, (b)粒子下落速度
Fig. 8 Vertical structure of an isolated convection at Dingyuan Station on 20 Jul 2013 (a)reflectivity, (b)particle fall velocity
表 1 C波段连续波雷达和多普勒天气雷达主要参数
Table 1 Main parameters of C-FMCW radar and Doppler radar
雷达参数 多谱勒天气雷达 C波段连续波雷达 探测方式 体扫描方式 固定式垂直指向 探测量程 水平460 km，垂直20 km 150 m~24 km 时间分辨率 6 min 3 s 空间分辨率 1 km 30 m 探测精度 ≤1 dBZ ≤1 dBZ 
下载: 导出CSV
表 2 2013—2016年6—9月不同对流云数量统计
Table 2 The number of different convections from Jun to Sep during 2013-2016
月份 孤立对流云数量 对流云数量 孤立对流云所占比例 6 30 157 19.1% 7 53 196 27% 8 89 228 39% 9 24 83 28.9%
下载: 导出CSV
-
[1] 朱士超, 袁野, 吴林林, 等.江淮对流云发生规律及其垂直结构分析.气象, 2016, 43(6):696-704. http://d.old.wanfangdata.com.cn/Periodical/qx201706006 [2] Rowe A K, Rutledge S A, Lang T J.Investigation of microphysical processes occurring in isolated convection during NAME.Mon Wea Rev, 2011, 139(2):424-443. doi: 10.1175/2010MWR3494.1 [3] 刘治国, 陶健红, 杨建才, 等.冰雹云和雷雨云单体VIL演变特征对比分析.高原气象, 2008, 27(6):1364-1372. http://www.cnki.com.cn/Article/CJFDTotal-GYQX200806021.htm [4] 岳治国, 牛生杰.洛川地区孤立对流云雷达回波特征分析.陕西气象, 2007(5):1-5. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=sxqx200705001 [5] 朱士超, 银燕, 金莲姬, 等.青藏高原一次强对流过程对水汽垂直输送的数值模拟.大气科学, 2011, 35(6):1057-1068. http://d.old.wanfangdata.com.cn/Periodical/daqikx201106006 [6] Rosenow A A, Plummer D M, Rauber R M, et al.Vertical velocity and physical structure of generating cells and convection in the comma head region of continental winter cyclones.J Atmos Sci, 2014, 71(5):1538-1558. doi: 10.1175/JAS-D-13-0249.1 [7] Hence D A, Houze R A.Vertical structure of tropical cyclone rainbands as seen by the TRMM precipitation Radar.J Atmos Sci, 2012, 69(9):2644-2661. doi: 10.1175/JAS-D-11-0323.1 [8] Marsham J H, Trier S B, Weckwerth T M, et al.Observations of elevated convection initiation leading to a surface-based squall line during 13 June IHOP_2002.Mon Wea Rev, 2010, 139(1):247-271. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=f8bec58eb3b259c8a73af66de224d6fa [9] DeMott C A, Rutledge S A.The vertical structure of TOGA COARE convection.Part Ⅰ:Radar echo distributions.J Atmos Sci, 1998, 55(17):2730-2747. https://www.researchgate.net/publication/242771583_The_vertical_structure_of_TOGA_COARE_convection_Part_I_radar_echo_distributions [10] Stephens G L, Wood N B.Properties of tropical convection observed by millimeter-wave radar systems.Mon Wea Rev, 2007, 135(3):821-842. doi: 10.1175/MWR3321.1 [11] Leary C A, Houze R A.The structure and evolution of convection in a tropical cloud cluster.J Atmos Sci, 1979, 36(3):437-457. doi: 10.1175/1520-0469(1979)036<0437:TSAEOC>2.0.CO;2 [12] Ryzhkov A V, Zrnić D S.Rain in shallow and deep convection measured with a polarimetric Radar.J Atmos Sci, 1996, 53(20):2989-2995. doi: 10.1175/1520-0469(1996)053<2989:RISADC>2.0.CO;2 [13] Stokes G M, Schwartz S E.The atmospheric radiation measurement (ARM) program:Programmatic background and design of the cloud and radiation test bed.Bull Amer Meteor Soc, 1994, 75(7):1201-1221. doi: 10.1175/1520-0477(1994)075<1201:TARMPP>2.0.CO;2 [14] Lerach D G, Rutledge S A, Williams C R.Vertical structure of convective systems during NAME 2004.Mon Wea Rev, 2009, 138(5):1695-1714. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=ed0c8d5012df1ef29434391e4860f467 [15] Sekelsky S M, Ecklund W L, Firda J M, et al.Particle size estimation in ice-phase clouds using multifrequency radar reflectivity measurements at 95, 33, and 2.8 GHz.J Appl Meteor, 1999, 38(1):5-28. doi: 10.1175/1520-0450(1999)038<0005:PSEIIP>2.0.CO;2 [16] Lombardo K A, Colle B A.The spatial and temporal distribution of organized convective structures over the northeast and their ambient conditions.Mon Wea Rev, 2010, 138(12):4456-4474. doi: 10.1175/2010MWR3463.1 [17] Heymsfield G M, Tian L, Heymsfield A J, et al.Characteristics of deep tropical and subtropical convection from nadir-viewing high-altitude airborne doppler Radar.J Atmos Sci, 2010, 67(2):285-308. doi: 10.1175/2009JAS3132.1 [18] 孙豪, 刘黎平, 郑佳锋.不同波段垂直指向雷达功率谱密度对比.应用气象学报, 2017, 28(4):447-457. doi: 10.11898/1001-7313.20170406 [19] 闵晶晶, 刘还珠, 曹晓钟, 等.天津"6.25"大冰雹过程的中尺度特征及成因.应用气象学报, 2011, 22(5):525-536. http://qikan.camscma.cn/jamsweb/article/id/20110502 [20] 阮征, 李淘, 金龙, 等.大气垂直运动对雷达估测降水的影响.应用气象学报, 2017, 28(2):200-208. doi: 10.11898/1001-7313.20170207 [21] 杨有林, 纪晓玲, 张肃诏, 等.基于雷达回波强度面积谱识别降水云类型.应用气象学报, 2018, 29(6):690-700. doi: 10.11898/1001-7313.20180605 [22] 金龙, 阮征, 葛润生, 等.C-FMCW雷达对江淮降水云零度层亮带探测研究.应用气象学报, 2016, 27(3):313-322. doi: 10.11898/1001-7313.20160306 [23] 曹杨, 陈洪滨, 苏德斌.C波段双线偏振天气雷达零度层亮带识别和订正.应用气象学报, 2018, 29(1):84-94. doi: 10.11898/1001-7313.20180108 [24] 袁野, 杨光, 胡雯.利用双多普勒天气雷达分析对流云垂直运动结构试验.应用气象学报, 2007, 18(3):306-313. http://qikan.camscma.cn/jamsweb/article/id/20070352 [25] 石宝灵, 王红艳, 刘黎平.云南多普勒天气雷达网探测冰雹的覆盖能力.应用气象学报, 2018, 29(3):270-281. doi: 10.11898/1001-7313.20180302 [26] 黎惠金, 李向红, 黄芳.广西一次特大暴雨的MCC演变过程及结构特征分析.高原气象, 2013, 32(3):806-817. http://d.old.wanfangdata.com.cn/Periodical/gyqx201303020 [27] Gallus W A, Snook N A, Johnson E V.Spring and summer severe weather reports over the midwest as a function of convective mode:A preliminary study.Wea Forcasting, 2008, 23(1):101-113. doi: 10.1175/2007WAF2006120.1 [28] 刘黎平, 郑佳锋, 阮征, 等.2014年青藏高原云和降水多种雷达综合观测试验及云特征初步分析结果.气象学报, 2015, 73(4):635-647. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=qxxb201504003 [29] 阮征, 金龙, 葛润生, 等.C波段调频连续波天气雷达探测系统及观测试验.气象学报, 2015, 73(3):577-592. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=qxxb201503014 [30] 李淘, 阮征, 葛润生, 等.激光雨滴谱仪测速误差对雨滴谱分布的影响.应用气象学报, 2016, 27(1):25-34. doi: 10.11898/1001-7313.20160103 -
计量
- 摘要浏览量: 3630
- HTML全文浏览量: 1942
- PDF下载量: 98
- 被引次数: 0
