Study on the Stable Components of Atmospheric Circulation during the Continuous Heavy Rainfall of Meiyu in 2016
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摘要: 梅雨降水具有显著的阶段变化特征,研究持续强降水期间的关键环流稳定分量,对于分析和预测梅雨降水具有重要意义。利用NCEP-DOE1979~2016年逐日再分析资料,对2016年梅雨持续强降水期间位势高度场、风场和相对湿度场进行分析,提取环流系统的关键稳定分量,并对其空间结构、演变特征及更长时间尺度的背景形势进行分析,为梅雨区阶段性强降水的延伸期预报提供依据和参考。研究发现:(1)在位势高度场稳定分量中存在的“三极”分布形势,是维持2016年梅雨持续强降水的关键系统。“三极”分别对应着乌拉尔山阻塞高压、鄂霍茨克海阻塞高压以及偏东偏强的南亚高压和偏西偏强的西太平洋副热带高压(副高)。这种配置结构有利于冷暖空气在梅雨区交汇形成持续性强降水。(2)在中高纬度两个正距平区之间,是相对深厚的负距平区,有利于建立冷空气的向南输送通道,同时相对湿度场稳定分量表明北支气流对水汽的输送和汇聚作用对于梅雨区持续降水起到重要作用。(3)中低纬度的正距平区域呈纬向带状分布,且主要存在于对流层中高层,在梅雨区东西两侧各有一个正距平下沉支,它们共同加强了梅雨区南侧暖湿气流的汇聚输送作用。(4)通过对稳定分量的演变分析发现,“三极”系统的建立和演化与梅雨区降水强弱的阶段变化密切相关。(5)更长时间尺度(60d)环流稳定分量为持续强降水时段的“三极”关键稳定分量提供了重要的环流背景。Abstract: There are significant precipitation stages that bring changes during the rainy period known as Meiyu. It is important to study the key stable circulation components that lead to the continuous heavy rainfall of this period to enable the analysis and prediction of Meiyu precipitation. Using NCEP/DOE Reanalysis II data from 1979 to 2016, the key stable components of the circulation system during the 2016 Meiyu period were extracted from the geopotential height field, wind field, and relative humidity field. The spatial structure, evolutionary characteristics, and longer-term background factors were analyzed to provide a basis for extended period forecasts of the periodic heavy rainfall in the Meiyu area. The results suggest that (1) the “tri-pole” pattern is the key system that maintained the continuous heavy rainfall in the Meiyu area in 2016. This “tri-pole” pattern in the stable components of the geopotential height field corresponds to the Ural Mountains blocking high, the Okhotsk Sea blocking high, the Southeast Asia high, and the West Pacific subtropical high. The structure of this configuration is conducive to the convergence of warm and cold air in the Meiyu area to generate persistent heavy rainfall. (2) In the middle and high latitudes, there is a relatively deep negative anomaly between two deep positive-anomaly areas. On one hand, this is conducive to the southward transport of cold air. On the other hand, the stability of the relative humidity field indicates that the water vapor transport and convergence of the northern branch of the air flow play an important role in the continuous precipitation of the Meiyu area. (3) The positive-anomaly area in the middle and low latitudes mainly occurs in the middle and high troposphere with zonal distribution features. However, there are two positive areas on both the eastern and western sides of the Meiyu area, which continue down to the lower level and may strengthen the convergence and transport of warm and humid air in the south of the Meiyu area. (4) The analysis of the evolution of the stable component revealed that the establishment and evolution of the “tri-pole” pattern led to different precipitation-stage characteristics in the Meiyu area.(5) The stable circulation components on a longer time scale (60 d) provide important background circulation for the key stable components of the “tri-pole” pattern during the period of continuous heavy rainfall.
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Key words:
- Meiyu /
- Stable components /
- Spatial structure /
- Evolution characteristics
1) 中国气象局预报与网络司. 2014. 关于印发《梅雨监测业务规定》的通知, 气预函(2014)28号 [R]. -
图 3 2016年6月18日至7月7日(研究时段,下同)梅雨区(277站平均)气温(等值线,单位:°C)、风和相对湿度(阴影区)时间—高度剖面
Figure 3. Time–height cross sections of the average air temperature (contours, units: °C),wind and relative humidity (shadings) in the Meiyu region (277-station average) from 18 Jun to 7 Jul 2016 (the research period, the same below)
图 4 研究时段平均位势高度场、相对湿度场和流场分布:(a) 100 hPa;(b) 500 hPa;(c) 700 hPa;(d) 850 hPa。图(a,b)中蓝色等值线为位势高度,红色等值线为气候平均,单位:gpm;图(a–d)阴影区为相对湿度
Figure 4. Distribution of the average geopotential height field, relative humidity field, and stream field during the research period at (a)100 hPa, (b)500 hPa, (c)700 hPa, and (d)850 hPa. The shaded areas in (a–d) indicate relative humidity, the contours in (a, b) indicate geopotential height, the red isolines indicate climate average (units: gpm)
图 5 研究时段位势高度场、相对湿度场和流场稳定分量分布:(a) 100 hPa;(b) 500 hPa;(c) 700 hPa;(d)850 hPa。图(a,b)等值线为位势高度(单位:gpm),图(a–d)阴影区为相对湿度
Figure 5. Distribution of the stable components of the geopotential height field, relative humidity field, and stream field during the research period at (a) 100 hPa, (b) 500 hPa, (c) 700 hPa, and (d) 850 hPa. The shaded areas in (a–d) indicate relative humidity, the contours in (a, b) indicate geopotential height (units: gpm)
图 6 研究时段位势高度场稳定分量垂直剖面分布(单位:gpm):(a)沿50°~70°E经度带平均;(b)沿90°~110°E经度带平均;(c)沿140°~160°E经度带平均;(d)沿45°~60°N纬度带平均;(e)沿30°~40°N纬度带平均;(f)沿20°~30°N纬度带平均
Figure 6. Vertical profile distribution of stable components of the geopotential height field during the research period (units: gpm): (a) Regional average along 50°–70°E; (b) regional average along 90°–110°E; (c) regional average along 140°–160°E; (d) regional average along 45°–60°N; (e) regional average along 30°–40°N; (f) regional average along 20°–30°N
图 7 研究时段及前、后时段位势高度场稳定分量(单位:gpm)对流层中上层(500~200 hPa)平均分布:(a)前一时段(2016年5月29日~6月17日,下同);(b)研究时段(2016年6月18日~7月7日);(c)后一时段(2016年7月8日~7月27日,下同)
Figure 7. Average distribution of stable components of the geopotential height field in the middle and upper troposphere (500–200 hPa) during, before, and after the research period (units: gpm): (a) The previous period (between 29 May and 17 Jun 2016, the same below); (b) research period (between 18 Jun and 7 Jul 2016, the same below); (c) later period (between 8 Jul and 27 Jul 2016, the same below)
图 8 研究时段及前后时段位势高度场稳定分量垂直分布(单位:gpm):(a)(50°~70°N,50°~70°E)区域平均;(b)(50°~70°N,90°~110°E)区域平均;(c)(50°~70°N,140°~160°E)区域平均;(d)(20°~40°N,50°~70°E)区域平均;(e)(20°~40°N,90°~110°E)区域平均;(f)(20°~40°N,140°~160°E)区域平均
Figure 8. Vertical distribution of the stable components of the geopotential height field during, before, and after the research period (units: gpm): (a) Regional average in (50°–70°N, 50°–70°E); (b) regional average in (50°–70°N, 90°–110°E); (c) regional averagein (50°–70°N, 140°–160°E); (d) regional average in (20°–40°N, 50°–70°E); (e) regional average in (20°–40°N, 90°–110°E); (f) regional average in (20°–40°N, 140°–160°E)
图 9 2016年研究时段及2009年同期位势高度场稳定分量垂直分布(单位:gpm):(a)(50°~70°N,50°~70°E)区域平均;(b)(50°~70°N,90°~110°E)区域平均;(c)(50°~70°N,140°~160°E)区域平均;(d)(20°~40°N,50°~70°E)区域平均;(e)(20°~40°N,90°~110°E)区域平均;(f)(20°~40°N,140°~160°E)区域平均
Figure 9. Vertical distribution of stable components of the geopotential height field during the research period in 2016 and 2009 (units: gpm): (a) Regional average in (50°-70°N,50°-70°E); (b) regional average in (50°–70°N, 90°–110°E); (c) regional average in (50°–70°N, 140°–160°E); (d) regional average in (20°–40°N, 50°–70°E); (e) regional average in (20°–40°N, 90°–110°E); (f) regional average in (20°–40°N, 140°–160°E)
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[1] 陈官军, 魏凤英. 2012. 基于低频振荡特征的夏季江淮持续性降水延伸期预报方法 [J]. 大气科学, 36(3): 633−644. doi: 10.3878/j.issn.1006-9895.2011.11111Chen Guanjun, Wei Fengying. 2012. An extended-range forecast method for the persistent heavy rainfall over the Yangtze–Huaihe River valley in summer based on the low-frequency oscillation characteristics [J]. Chinese Journal of Atmospheric Sciences (in Chinese), 36(3): 633−644. doi: 10.3878/j.issn.1006-9895.2011.11111 [2] 封国林, 杨涵洧, 张世轩, 等. 2012. 2011年春末夏初长江中下游地区旱涝急转成因初探 [J]. 大气科学, 36(5): 1009−1026. doi: 10.3878/j.issn.1006-9895.2012.11220Feng Guolin, Yang Hanwei, Zhang Shixuan, et al. 2012. A preliminary research on the reason of a sharp turn from drought to flood in the middle and lower reaches of the Yangtze River in late spring and early summer of 2011 [J]. Chinese Journal of Atmospheric Sciences (in Chinese), 36(5): 1009−1026. doi: 10.3878/j.issn.1006-9895.2012.11220 [3] 何金海, 杨松. 1992. 东亚地区低频振荡的经向传播及中纬度的低频波动 [J]. 气象学报, 50(2): 190−198. doi: 10.11676/qxxb1992.021He Jinhai, Yang Song. 1992. Meridional propagation of East Asian low-frequency mode and midlatitude low-frequency waves [J]. Acta Meteor. Sinica (in Chinese), 50(2): 190−198. doi: 10.11676/qxxb1992.021 [4] Jiang X N, Waliser D E. 2009. Two dominant subseasonal variability modes of the eastern Pacific ITCZ [J]. Geophys. Res. Lett., 36(4): L04704. doi: 10.1029/2008GL036820 [5] Kanamitsu M, Ebisuzaki W, Woollen J, et al. 2002. NCEP-DOE AMIP-II reanalysis (R-2) [J]. Bull. Amer. Meteor. Soc., 83(11): 1631−1644. doi: 10.1175/BAMS-83-11-1631 [6] Krishnamurti T N, Gadgil S. 1985. On the structure of the 30 to 50 day mode over the globe during FGGE [J]. Tellus A, 37(4): 336−360. doi: 10.3402/tellusa.v37i4.11677 [7] 李崇银. 1991. 30~60天大气振荡的全球特征 [J]. 大气科学, 15(3): 66−76. doi: 10.3878/j.issn.1006-9895.1991.03.10Li Chongyin. 1991. Global characteristics of 30-60 day atmospheric oscillation [J]. Chinese Journal of Atmospheric Sciences (Scientia Atmos. Sinica) (in Chinese), 15(3): 66−76. doi: 10.3878/j.issn.1006-9895.1991.03.10 [8] Li S L, Ji L R, Lin W T, et al. 2001. The maintenance of the blocking over the Ural mountains during the second Meiyu period in the summer of 1998 [J]. Adv. Atmos. Sci., 18(1): 87−105. doi: 10.1007/s00376-001-0006-4 [9] 李维京. 1999. 1998年大气环流异常及其对中国气候异常的影响 [J]. 气象, 25(4): 20−25. doi: 10.3969/j.issn.1000-0526.1999.04.004Li Weijing. 1999. General atmospheric circulation anomaly in 1998 and their impact on climate anomaly in China [J]. Meteorological Monthly (in Chinese), 25(4): 20−25. doi: 10.3969/j.issn.1000-0526.1999.04.004 [10] 李志锦, 纪立人. 1996. 实际预报可预报性的时空依赖性分析 [J]. 大气科学, 20(3): 290−297. doi: 10.3878/j.issn.1006-9895.1996.03.04Li Zhijin, Ji Liren. 1996. Analysis of the dependence of predictability on spatial and temporal scales from operational forecasts [J]. Chinese Journal of Atmospheric Sciences (Scientia Atmos. Sinica) (in Chinese), 20(3): 290−297. doi: 10.3878/j.issn.1006-9895.1996.03.04 [11] 梁萍, 丁一汇. 2011. 2009年是空梅吗? [J]. 高原气象, 30(1): 53−64.Liang Ping, Ding Yihui. 2011. Does non-occurrence of Meiyu take place in Yangtze–Huaihe basins during summer of 2009? [J]. Plateau Meteorology (in Chinese), 30(1): 53−64. [12] 梁萍, 丁一汇. 2012. 东亚梅雨季节内振荡的气候特征 [J]. 气象学报, 70(3): 418−435. doi: 10.11676/qxxb2012.036Liang Ping, Ding Yihui. 2012. Climatologic characteristics of the intraseasonal oscillation of East Asian Meiyu [J]. Acta Meteor. Sinica (inChinese), 70(3): 418−435. doi: 10.11676/qxxb2012.036 [13] Madden R A, Julian P R. 1971. Detection of a 40-50 day oscillation in the zonal wind in the tropical Pacific [J]. J. Atmos. Sci., 28(5): 702−708. doi:10.1175/1520-0469(1971)028<0702:DOADOI>2.0.CO;2 [14] Ninomiya K, Nishimura T, Ohfuchi W, et al. 2002. Features of the Baiu front simulated in an AGCM(T42L52) [J]. J. Meteor. Soc. Japan, 80(4): 697−716. doi: 10.2151/jmsj.80.697 [15] 庞玥, 王黎娟, 于波. 2013. 江淮流域梅雨期降水与10~30d低频振荡的联系 [J]. 大气科学学报, 36(6): 742−750. doi: 10.3969/j.issn.1674-7097.2013.06.011Pang Yue, Wang Lijuan, Yu Bo. 2013. The relationship between 10-30 d low-frequency oscillation and the rainfall over Changjiang–Huaihe River valley during Meiyu period [J]. Trans. Atmos. Sci. (in Chinese), 36(6): 742−750. doi: 10.3969/j.issn.1674-7097.2013.06.011 [16] Pearson K. 1901. LIII. On lines and planes of closest fit to systems of points in space [J]. The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science, 2(11): 559−572. doi: 10.1080/14786440109462720 [17] 施能. 2009. 气象统计预报 [M]. 北京: 气象出版社, 128–142.Shi Neng. 2009. Meteorological Statistical Forecast (in Chinese) [M]. Beijing: China Meteorological Press, 128–142. [18] Teng H Y, Wang B. 2003. Interannual variations of the boreal summer intraseasonal oscillation in the Asian–Pacific region [J]. J. Climate, 16(22): 3572−3584. doi:10.1175/1520-0442(2003)016<3572:IVOTBS>2.0.CO;2 [19] 王丽娟. 2008. 东北冷涡过程对江淮梅雨期降水影响机制的分析 [D]. 南京信息工程大学硕士学位论文, 82pp.Wang Lijuan. 2008. Analysis to the Impacts of the Northeast Cold Vortex (NECV) process on the rainfall during Meiyu period over the Yangtze–Huaihe River [D]. M. S. thesis (in Chinese), Nanjing University of Information Science &Technology, 82pp. [20] 杨秋明. 2009. 全球环流20~30 d振荡与长江下游强降水 [J]. 中国科学(D辑): 地球科学, 52(10): 1485−1501. doi: 10.1007/s11430-009-0156-2Yang Qiuming. 2009. The 20-30-day oscillation of the global circulation and heavy precipitation over the lower reaches of the Yangtze River valley [J]. Science in China (Series D): Earth Sciences, 52(10): 1485−1501. doi: 10.1007/s11430-009-0156-2 [21] 杨双艳, 武炳义, 张人禾, 等. 2013. 夏季欧亚中高纬大气低频振荡的纬向传播特征 [J]. 中国科学: 地球科学, 56(9): 1566−1575. doi: 10.1007/s11430-012-4576-zYang Shuangyan, Wu Bingyi, Zhang Renhe, et al. 2013. The zonal propagating characteristics of low-frequency oscillation over the Eurasian mid-high latitude in boreal summer [J]. Science ChinaEarth Sciences, 56(9): 1566−1575. doi: 10.1007/s11430-012-4576-z [22] 曾宇星. 2016. 基于历史资料提取稳定分量方法的改进研究及在模式中的应用 [D]. 兰州大学博士学位论文, 110pp.Zeng Yuxing. 2016. Improvement research of stable component extraction based on historical data and its application on numerical model [D]. Ph. D. dissertation (in Chinese), Lanzhou University, 110pp. [23] 赵俊虎, 陈丽娟, 王东阡. 2018. 2016年我国梅雨异常特征及成因分析 [J]. 大气科学, 42(5): 1055−1066. doi: 10.3878/j.issn.1006-9895.1708.17170Zhao Junhu, Chen Lijuan, Wang Dongqian. 2018. Characteristics and causes analysis of abnormal Meiyu in China in 2016 [J]. Chinese Journal of Atmospheric Sciences (in Chinese), 42(5): 1055−1066. doi: 10.3878/j.issn.1006-9895.1708.17170 [24] 郑志海, 封国林, 丑纪范, 等. 2010. 数值预报中自由度的压缩及误差相似性规律 [J]. 应用气象学报, 21(2): 139−148. doi: 10.3969/j.issn.1001-7313.2010.02.002Zheng Zhihai, Feng Guolin, Chou Jifan, et al. 2010. Compression for freedom degree in numerical weather prediction and the error analogy [J]. Journal of Applied Meteorological Science (in Chinese), 21(2): 139−148. doi: 10.3969/j.issn.1001-7313.2010.02.002 [25] 郑志海, 黄建平, 封国林, 等. 2013. 延伸期可预报分量的预报方案和策略 [J]. 中国科学: 地球科学, 56(5): 878−889. doi: 10.1007/s11430-012-4513-1Zheng Zhihai, Huang Jianping, Feng Guolin, et al. 2013. Forecast scheme and strategy for extended-range predictable components [J]. Science China Earth Sciences, 56(5): 878−889. doi: 10.1007/s11430-012-4513-1 [26] 周兵, 文继芬. 2007. 1998年夏季我国东部降水与大气环流异常及其低频特征 [J]. 应用气象学报, 18(2): 129−136. doi: 10.3969/j.issn.1001-7313.2007.02.001Zhou Bing, Wen Jifen. 2007. Abnormality of summertime precipitation of eastern China and general circulation with LFO in 1998 [J]. J. Appl. Meteor. Sci. (in Chinese), 18(2): 129−136. doi: 10.3969/j.issn.1001-7313.2007.02.001 -