Variations of Torrential Rain in First Rainy Season in Guangdong Province and Its Relationships with the Biweekly Oscillation of 500 hPa Key Region

Ji Zhongping; Gu Dejun; Wu Naigeng; Xie Jiongguang

Vol.21, NO.6, 2010

Article Contents

Article Navigation > Journal of Applied Meteorological Science > 2010 > 21(6): 671-684

Ji Zhongping, Gu Dejun, Wu Naigeng, et al. Variations of torrential rain in first rainy season in Guangdong Province and its relationships with the biweekly oscillation of 500 hPa key region. J Appl Meteor Sci, 2010, 21(6): 671-684.

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Variations of Torrential Rain in First Rainy Season in Guangdong Province and Its Relationships with the Biweekly Oscillation of 500 hPa Key Region

1.
Guangzhou Central Weather Observatory, Guangzhou 510080
2.
State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing 100081
3.
Guangzhou Institute of Tropical and Marine Meteorology, Key Open Laboratory for Tropical Monsoon, China Meteorological Administration, Guangzhou 510080

Received Date: 2009-12-03
Rev Recd Date: 2010-08-15
Publish Date: 2010-12-31

Abstract

Abstract

In order to improve medium range prediction of torrential rain in Guangdong Province, the variation characteristics of the torrential rain in first rainy season and their relationships with biweekly oscillation of a key region at 500 hPa geopotential height are investigated with wavelet analysis, power spectrum analysis, cross spectrum analysis and Lanczos filter using the daily precipitation data of 86 stations and rainfall regimes, and NCEP/NCAR daily data for the last 48 years of 1961-2008. The results show that torrential rain during June has increased in both the number of days and intensity since the 1990s, but the total number of torrential rain days for the season has decreased since the end of the 1990s, exhibiting significant quasi periodic oscillations of 6—7 years. The storm rainfall accounts for 37.7% of total rainfall during Guangdong first rainy season, and is significantly positive correlated to the total rainfall. The area (20°-30°N, 102.5°-120°E) with 500 hPa geopotential height is significantly negative correlated with the daily precipitation during April-June in Guangdong, named as the 500 hPa key region. The daily precipitation during April-June in Guangdong and 500 hPa key region exhibit significant quasi weekly (5—9 days) and quasi bi weekly (10-20 days) oscillations but less significant 30—60 days oscillations. The relation between 500 hPa key region and the daily precipitation during April—June in Guangdong Province in the quasi biweekly oscillation scale is most close connected, and the lead or lag time of oscillation is within 2 days. From April to June over the 48 years, the probability of torrential rain is 79% within three or four days (in fewer cases) before or after the valleys of the quasi biweekly oscillations in the 500 hPa key region. The characteristics of atmospheric circulation with or without torrential rain in Guangdong Province for quasi biweekly oscillatory valleys of 500 hPa key region are analyzed with the composite analysis of typical examples. When the torrential rain happens near the valleys, the cold air moves southward by significantly enhanced trough over East Asian, meanwhile, trough over the Bay of Bengal significantly deepens and widens, and torrential rain in Guangdong Province are caused by the interaction between north cold air and southwest warm and moist air brought by strong southwest flow from the Bay of Bengal. When no torrential rain happens near the valleys, the cold air acts northward, no significantly transfer of water vapor moisture transport from the Bay of Bengal, Guangdong Province is controlled by strong southwesterly at the verge of subtropical high and is located in the divergent region of moisture flux, the rainfall is weaker. All these are not conducive to the occurrence of rainfall, especially torrential rain. Therefore, the significant difference between the circulation fields can be used as reference for medium range forecast of torrential rain in Guangdong Province.
- torrential rain in first rainy season;
- 500 hPa key region biweekly oscillation;
- medium range forecast;

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References(41)

Figures and Tables

图 1 1961-2008年4-6月广东省暴雨日数 (a) 及4-6月暴雨量占总降水量的百分比 (b)

Fig. 1 The number of Guangdong torrential rain day during April-June (a) and the percentage of storm rainfall accounting for total rainfall during April-June (b) from 1961 to 2008

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图 2 1961-2008年4-6月广东省暴雨总日数的变化 (a) 及其墨西哥帽小波分析 (b) 与小波功率谱 (c)

(图a中实横线代表广东省4-6月暴雨总日数的历年平均值:17.3d, 虚线为高斯九点平滑滤波；图b中阴影区表示达到0.10显著性水平的区域，两边的交叉区域表示边界效应的影响域)

Fig. 2 The number of Guangdong torrential rain day during April-June from 1961 to 2008(a) with its Mexican wavelet analysis (b) and its global wavelet power spectrum (c)

(the horizontal solid line stands for 17.3 days, the mean days of Guangdong torrential rain during April-June from 1961 to 2008, and dashed line stands for smoothed filtered by 9 points Gaussian smoothing in Fig.2a; the shaded areas represent regions with significance level of 0.10 and the cross hatched regions on both ends indicate the areas with boundary effects in Fig.2b)

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图 3 1961-2008年4-6月广东省86站平均逐日降水与500hPa高度场逐年相关系数的多年平均分布

(浅色阴影:通过0.05显著性水平检验；深色阴影:通过0.01显著性水平检验；矩形区:本文定义的500hPa关键区)

Fig. 3 The distribution of mean correlation coefficient between daily Guangdong rainfall averaged by 86 stations and geopotental height field at 500 hPa during April-June from 1961 to 2008

(the light and deep shaded area stands for passing the significance level of 0.05 and 0.01, respectively; the rectangular area is 500 hPa key region defined in this paper)

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图 4 1961-2008年4-6月逐日降水与500hPa关键区的凝聚谱值与0.05显著性水平谱值之比 (阴影区为比值≥1的区域，表示通过0.05显著性水平检验)(a) 及落后时间长度 (b)

Fig. 4 The ratio of the coherence spectrum of the daily precipitation and index of 500 hPa key region to the spectrum with 0.05 significance level (shaded areas with the ratio≥1 passes the significance level of 0.05)(a) and their lag-temporal spectrum (b) during April-June from 1961 to 2008

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图 5 2000年3-7月500hPa关键区位势高度逐日距平 (a) 与广东省86站平均逐日降水 (b) 及其经10~20d滤波的低频分量

(图中粗虚线为10~20d滤波；图a中水平细虚线表示10~20d低频序列的1倍标准差，数字1~5表示准双周振荡的5个不同位相)

Fig. 5 The daily anomaly of 500 hPa key region index (a) and daily mean rainfall of Guangdong (b) with their10-20-day Lanczos filter during March-July iN₂000

(the thick dashed line is for 10-20-day Lanczos filter; the thin dashed horizontal line denotes one standard deviation of the10-20-day oscillation, and number1-5 represent the five different phases of the10-20-day oscillation in Fig.5a)

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图 6 500hPa关键区准双周振荡低频波谷附近有暴雨的500hPa高度场 (单位:dagpm) 与850hPa风场位相1~4的合成场分布

Fig. 6 The composition of 500 hPa geopotential height field (unit:dagpm) and 850 hPa wind field for Phase 1-4 with the torrential rain in first rainy season in Guangdong associated with the quasi-biweekly oscillatory valleys of the 500 hPa key region index

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图 7 500hPa关键区准双周振荡低频波谷附近有、无暴雨的850hPa水汽输送 (矢量，单位:kg·hPa^-1·m^-1·s^-1) 及^{水汽通量散度 (等值线，单位:10^-7}kg·hPa^-1·m^-2·s^-1)1~4个位相的合成场分布

Fig. 7 The composition of 850hPa moisture flux (vectors, unit:kg·hPa^-1·m^-1·s^-1) and moisture flux divergence (isolines, unit:10^-7kg·hPa^-1·m^-2·s^-1) for Phase 1-4 with or without the torrential rain in first rainy season in Guangdong associated with the quasi-biweekly oscillatory valleys of the 500 hPa key region inde

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图 8 同图 6，但为无暴雨时

Fig. 8 Same as in Fig.6, but for the case without the torrential rain in first rainy season in Guangdong associated with the quasi-biweekly oscillatory valleys of the 500hPa key region index

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表 1 1961-2008年4-6月逐日降水功率谱分析得到的5d以上主要周期

Table 1 The main period above5days of the daily precipitation during April-June from 1961 to2008 in Guangdong by Fourier power spectra analysis

表 2 1961-2008年4-6月逐日500hPa关键区功率谱分析得到的5d以上主要周期

Table 2 The main period above 5 days of the daily 500 hPa key region duringApril-June from 1961 to 2008 in Guangdong by Fourier power spectra analysis

References

[1]	Madden R A, Julian P R.Detection of a 40~50 day oscillation in the zonal wind in the tropical Pacific.J Atmos Sci, 1971, 28:702-708. doi: 10.1175/1520-0469(1971)028<0702:DOADOI>2.0.CO;2
[2]	Madden R A, Julian P R.Description of globe scale circulation cells in the tropics with 40~50 day period.J Atmos Sci, 1972, 29:1109-1123. doi: 10.1175/1520-0469(1972)029<1109:DOGSCC>2.0.CO;2
[3]	Lau K M, Yang GJ, Shen S H. Seasonal and intraseasonal climatology of summer monsoon rainfalls over East Asia.Mon Wea Rev, 1988, 116:18-37. doi: 10.1175/1520-0493(1988)116<0018:SAICOS>2.0.CO;2
[4]	Mo K C.Intrasasonal modulation of summer precipitation over North America.Mon Wea Rev, 2000, 128:1490-1505. doi: 10.1175/1520-0493(2000)128<1490:IMOSPO>2.0.CO;2
[5]	Krishnamurthy V, Shukla J.Intraseasonal and interannual variability of rainfall over India.J Clim, 2000, 13:4366-4377. doi: 10.1175/1520-0442(2000)013<0001:IAIVOR>2.0.CO;2
[6]	Jones C, Waliser D E, Lau K M, et al.Global occurrences of extreme precipitation and the Madden-Julian Oscillation:Observations and predictability.J Clim, 2004, 17:4575-4589. doi: 10.1175/3238.1
[7]	Barlow M, Wheeler M, Lyon B, et al.Modulation of daily precipitation over southwest Asia by the Madden-Jullian Os-cillation.Mon Wea Rev, 2005, 133:3579-3594. doi: 10.1175/MWR3026.1
[8]	Krishnamurthy V, Shukla J.Intraseasonal and seasonally persisting patterns of Indian monsoon rainfall.J Clim, 2007, 20:3-20. doi: 10.1175/JCLI3981.1
[9]	Hoyos C D, Webster P J.The role of intraseasonal variability in the nature of Asian monsoon precipitation.JClim, 2007, 20:4402-4424. https://www.researchgate.net/publication/253161843_The_Role_of_Intraseasonal_Variability_in_the_Nature_of_Asian_Monsoon_Precipitation
[10]	缪锦海, 刘家铭.东亚夏季降水中30~60d低频振荡.大气科学, 1991, 15(5):65-71. http://www.cnki.com.cn/Article/CJFDTOTAL-DQXK199105007.htm
[11]	杨广基.中国东部降水和风场的低频振荡特征.大气科学, 1992, 16(1):103-110. http://www.cnki.com.cn/Article/CJFDTOTAL-DQXK199201014.htm
[12]	黄菲, 黄少妮, 张旭.中国降水季节内振荡的气候特征分析.中国海洋大学学报, 2008, 8(2):173-177. http://www.cnki.com.cn/Article/CJFDTOTAL-QDHY200802002.htm
[13]	李崇银.华北地区汛期降水的一个分析研究.气象学报, 1992, 50(1):41-49. http://www.cnki.com.cn/Article/CJFDTOTAL-QXXB199201004.htm
[14]	陈丽臻, 张先恭, 陈隆勋.长江流域两个典型旱?涝年大气30~60d低频波差异的初步分析.应用气象学报, 1994, 5(4):483-488. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=19940482&flag=1
[15]	Yang H, Li CY.The relation between atmospheric intraseasonal oscillation and summer severe flood and drought in the Changjing-Huanhe river basin.Adv Atmos Sci, 2003, 2(4):540-553.
[16]	杨信杰, 罗坚, 乔金明, 等.1991年江淮暴雨与20~25d低频振荡.气象科学, 1994, 14(4):354-361. http://www.cnki.com.cn/Article/CJFDTOTAL-QXKX199404006.htm
[17]	陆尔, 丁一汇.1991年江淮特大暴雨与东亚大气低频振荡.气象学报, 1996, 54(6):730-736. http://www.cnki.com.cn/Article/CJFDTOTAL-QXXB606.008.htm
[18]	毛江玉, 吴国雄.1991年江淮梅雨与副热带高压的低频振荡.气象学报, 2005, 63(5):762-770. http://www.cnki.com.cn/Article/CJFDTOTAL-QXXB200505019.htm
[19]	琚建华, 赵尔旭.东亚夏季风区的低频振荡对长江中下游旱涝的影响.热带气象学报, 2005, 21(2):163-171. http://www.cnki.com.cn/Article/CJFDTOTAL-RDQX200502006.htm
[20]	陈晓红, 张娇.2004年安徽省梅汛期三次暴雨过程的大气低频振荡背景.应用气象学报, 2005, 16(6):754-762. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20050698&flag=1
[21]	周兵, 文继芬.1998年夏季我国东部降水与大气环流异常及其低频特征.应用气象学报, 2006, 17(3):129-136. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20070225&flag=1
[22]	琚建华, 孙丹, 吕俊梅.东亚季风涌对我国东部大尺度降水过程的影响分析.大气科学, 2007, 31(6):1129-1139. http://www.cnki.com.cn/Article/CJFDTOTAL-DQXK200706010.htm
[23]	张瑛, 陈隆勋, 何金海, 等.1998年夏季亚洲地区低频大气环流的特征及其与长江中下游降水的关系.气象学报, 2008, 66(44):577-591. http://www.cnki.com.cn/Article/CJFDTOTAL-QXXB200804010.htm
[24]	史学丽, 丁一汇.1994年中国华南大范围暴雨过程的形成与夏季风活动的研究.气象学报, 2000, 58(6):666-678. http://www.cnki.com.cn/Article/CJFDTOTAL-QXXB200006002.htm
[25]	信飞, 肖子牛, 李泽椿.1997年华南汛期降水异常与大气低频振荡的关系.气象, 2007, 33(12):23-30. http://www.cnki.com.cn/Article/CJFDTOTAL-QXXX200712005.htm
[26]	唐天毅, 吴池胜, 王安宇, 等.1999年广东汛期降水的季节内振荡.热带气象学报, 2007, 23(6):683-689. http://www.cnki.com.cn/Article/CJFDTOTAL-RDQX200706024.htm
[27]	朱乾根, 林锦瑞, 寿绍文, 等.天气学原理 (第四版).北京:气象出版社, 2007.
[28]	Torrence C, Gilbert P C.A practical guide to wavelet analysis.Bull Amer Meteor Soc, 1998, 79:61-78. doi: 10.1175/1520-0477(1998)079<0061:APGTWA>2.0.CO;2
[29]	谷德军, 王东晓, 纪忠萍, 等.墨西哥帽小波变换的影响域和计算方案新探讨.应用气象学报, 2009, 20(1):62-69. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20090108&flag=1
[30]	黄嘉佑, 李黄.气象中的谱分析.北京:气象出版社, 1984:13-142.
[31]	陈兴跃, 王会军, 曾庆存.大气季节内振荡及其年际变化.北京:气象出版社, 2000:142-144.
[32]	张腾飞, 鲁亚斌, 张杰.2000年以来云南4次强降雪过程的对比分析.应用气象学报, 2007, 18(1):64-72. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20070112&flag=1
[33]	陈隆勋, 朱乾根, 罗会邦, 等.东亚季风.北京:气象出版社, 1991:62-68.
[34]	池艳珍, 何金海, 吴志伟.华南前汛期不同降水时段的特征分析.南京气象学院学报, 2005, 28(2):163-171. http://www.cnki.com.cn/Article/CJFDTOTAL-NJQX200502002.htm
[35]	谢炯光, 纪忠萍, 谷德军, 等.广东省前汛期连续暴雨的气候背景及中期环流特征.应用气象学报, 2006, 17(3):354-362. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20060361&flag=1
[36]	广东省气象局《广东省天气预报技术手册》编写组.广东省天气预报技术手册.北京:气象出版社, 2006:90-141.
[37]	林良勋, 吴乃庚, 黄忠, 等.广东2008年罕见"龙舟水"特点及成因诊断分析.气象, 2009, 35(4):43-50. http://www.cnki.com.cn/Article/CJFDTOTAL-QXXX200904007.htm
[38]	彭丽英, 王谦谦, 马慧.华南前汛期暴雨气候特征的研究.南京气象学院学报, 2006, 29(2):249-253. http://www.cnki.com.cn/Article/CJFDTOTAL-NJQX200602015.htm
[39]	鲍名.近50年我国持续性暴雨的统计分析及其大尺度环流背景.大气科学, 2007, 31(5):779-792. http://www.cnki.com.cn/Article/CJFDTOTAL-DQXK200705002.htm
[40]	李真光, 邓良焱, 薛惠娴.华南前汛期大范围暴雨的合成分析.热带气象, 1988, 4(2):97-106. http://www.cnki.com.cn/Article/CJFDTOTAL-RDQX198802000.htm
[41]	《华南前汛期暴雨》编写组.华南前汛期暴雨.广州:广东科技出版社, 1986:55-58.