INTERDECADAL CHANGE OF THE SEASONAL EVOLUTION OF RAINFALL OVER SOUTH CHINA
-
摘要: 利用中国测站的逐日降水资料和NCEP/NCAR再分析资料，分析了近35年华南降水季节演变的年代际变化特征及其相关的大气环流异常特征。华南地区降水季节分布型在1990年代初期发生了年代际转变，其中，华南西部降水在1990年之前为双峰型分布，1990年之后变为以6月为峰值的单峰型分布；华南东部降水在1990年之前是以5月、8月为峰值的弱双峰型分布，1990年之后变为以6月、8月为峰值的显著双峰型分布。华南东、西部降水季节分布的年代际变化分别与华南全区6月降水量的年代际增加以及8月华南东、西部降水显著反相的年代际变化（东多西少）密切相关。1990年之后，大雨及以上强降水事件发生频率的增强是导致上述年代际变化的主要原因。华南6月降水年代际的增强与南海区域的西北太平洋副热带高压（简称西太副高）脊线位置的年代际异常偏南密切相关。7月华南地区降水的年代际增加与西太副高年代际东撤及影响华南地区的热带气旋频数年代际增多有关。8月华南东、西部降水显著反相的年代际变化（东多西少），一方面受印度洋及南海上空夏季风年代际减弱的影响，使得输送到华南西部的水汽减少，另一方面西太副高的年代际增强并西伸，使得源自副高西南侧的水汽更直接输送至华南东部地区有关；同时也与登陆和影响华南东、西部的热带气旋的年代际增多和减少有关。Abstract: This paper studies the interdecadal change of the seasonal evolution of rainfall over South China and its atmospheric circulation anomalies in the recent 35 years, based on the observed daily precipitation data from 1979 to 2013 provided by China Meteorological Administration and the reanalysis data of NCEP/NCAR. The seasonality of rainfall evolution in South China experienced an interdecadal change in the early 1990s. However, the interdecadal changes of rainfall seasonality in the eastern and western South China are different to each other. The precipitation pattern of seasonal distribution in the western South China changed from a bimodal pattern to an unimodal pattern with a peak in June around 1990, while in the eastern South China the weak bimodal precipitation pattern with two peaks in May and August, respectively, turned into a significant bimodal pattern with two peaks appearing in June and August, respectively, around 1990. The study also shows that the interdecadal changes of the seasonal precipitation pattern in both eastern and western South China are closely related to the interdecadal increase of precipitation in June in South China and the significant inverse interdecadal change in the east and the west of South China (less rainfall in the west part and more rainfall in the east part) in August, which are directly contributed by the significant interdecadal change of heavy precipitation frequency around 1990. The increase of precipitation over South China in June is caused by the interdecadal southward advancement of the western Pacific subtropical high after 1990, while the interdecadal increase of precipitation over South China in July results from the interdecadal eastward withdrawal of the western Pacific subtropical high, and the interdecadal increase of tropical cyclones affecting South China. The significant out-of-phase interdecadal change in both the east and west part of South China in August is associated with the interdecadal weakening of South tropical Asian summer monsoon, which leads to a weak transport of water vapor to the western South China, and the interdecadal intensification of the western Pacific Subtropical high and its westward extension forced by the interdecadal warming of sea surface temperature in the subtropical northwestern Pacific, which results in intensified water vapor transport to the eastern South China from the southwestern flank of the western Pacific subtropical high. Meanwhile, the interdecadal change of tropical cyclones affecting South China has direct impact on the interdecadal change of precipitation over South China in August.
-
Key words:
- climatology /
- precipitation feature /
- South China /
- seasonal evolution /
- interdecadal change
-
图 5 华南西部时段Ⅰ(实线)和时段Ⅱ(虚线)的平均逐候降水量曲线以及时段Ⅱ与时段Ⅰ的差值(直方图)
a.小雨；b.中雨；c.大雨；d.暴雨及以上(>50 mm/day)。单位：mm。
图 10 5—8月（a~d）各月时段Ⅱ与时段Ⅰ的大气环流年代际的差值场和时段Ⅱ平均的5—8月（e~g）各月大气环流场
矢量为850 hPa风场，填色为500 hPa的p坐标垂直运动（单位：Pa/s，紫色打点区域为通过5%信度检验的区域），等值线为500 hPa高度场（位势高度值扣除0~40 °N全球纬度带平均值）的合成场（绿色代表时段Ⅰ，红色代表时段Ⅱ，单位：gpm），虚线为副高脊线。
-
[1] 郭其蕴, 沙万英.华南前汛期降水变率的分析[J].应用气象学报, 1998, 9(1): 9-15. [2] 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[J].南京气象学院学报, 2005, 28(2): 163-171. [3] LUO H B. The onset of South China Sea monsoon and evolutions of its associated rainbands[C]//Onset and evolution of the South China Sea monsoon and its interaction with the ocean. Beijing: China Meteorological Press, 1999: 25-30. [4] 郑彬, 梁建茵, 林爱兰, 等.华南前汛期的锋面降水和夏季风降水Ⅰ:划分日期的确定[J].大气科学, 2006, 30(6): 1207-1216. [5] 吴丽姬, 温之平, 贺海晏, 等.华南前汛期区域持续性暴雨的分布特征及分型[J].中山大学学报(自然科学版), 2007, 46(6): 108-113. [6] ZHOU X, XUE J, TAO Z, et al. Numerical study on rainstorms over South China in 1998[C]//Beijing: China Meteorological, 2003: 220-225. [7] WANG H J. The weakening of the Asian monsoon circulation after the end of 1970's[J]. Adv Atmos Sci, 2001, 18(3): 376-386. [8] 赵振国, 朱艳峰, 柳艳香, 等. 1880-2006年中国夏季雨带类型的年代际变化特征[J].气候变化研究进展, 2008, 4(2): 95-100. [9] 司东, 丁一汇, 柳艳菊.中国梅雨雨带年代际尺度上的北移及其原因[J].科学通报, 2010, 55(1): 68-73. [10] ZHU Y L, WANG H J, ZHOU W, et al. Recent changes in the summer precipitation pattern in East China and the background circulation[J]. Clim Dyn, 2011, 36(7-8): 1463-1473. [11] KWON M, JHUN J G, HA K J. Decadal change in East Asian summer monsoon circulation in the mid-1990s[J]. Geophys Res Lett, 2007, 34(21): 377-390. [12] DING Y, WANG Z Y, SUN Y. Inter-decadal variation of the summer precipitation in East China and its association with decreasing Asian summer monsoon, Part Ⅰ: Observed evidences[J]. Int J Climatol, 2008, 28(9): 1139-1161. [13] ZHU Y, WANG H, ZHOU W, et al. Recent changes in the summer precipitation pattern in East China and the background circulation[J]. Clim Dyn, 2011, 36(7-8): 1463-1473. [14] WU W, WEN Z P, CHEN Y G. Interannual variability of winter and spring precipitation in south China and its relation to moisture transport[J]. J Trop Meteorol, 2013, 19(4): 322-330. [15] 高辉, 蒋薇, 李维京.近20年华南降水季节循环由双峰型向单峰型的转变[J].科学通报, 2013, 58(15): 1438-1443. [16] LUO X, ZHANG Y C. Interdecadal change in the seasonality of rainfall variation in South China[J]. Theor Appl Climatol, 2015, 119 (1-2): 1-11. [17] 郭进修, 王秀荣, 王维国.中国气象地理区划手册[M].北京:气象出版社, 2006: 2-3. [18] KALNAY E, KANAMITSU M, KISTLER R, et al. The NCEP/NCAR 40-year reanalysis project[J]. Bull Amer Meteorol Soc, 1996, 77(3): 437-471. [19] KISTLER R, COLLINS W, SAHA S, et al. The NCEP-NCAR 50-year reanalysis: Monthly means CD-ROM and documentation[J]. Bull Amer Meteorol Soc, 2001, 82(2): 247-268. [20] 伍红雨, 杜尧东, 陈桢华, 等.华南雨日、雨强的气候变化[J].热带气象学报, 2011, 27(6): 877-888. [21] YANG R, XIE Z, CAO J. A Dynamic Index for the Westward ridge point variability of the Western Pacific subtropical high during summer[J]. J Clim, 2017, 30(9): 3225-3341. [22] WU L, WANG C. Has the Western Pacific subtropical high extended Westward since the late 1970s?[J]. J Clim, 2015, 28(13): 5406- 5413. [23] WANG H J, CHEN H P. Climate control for southeastern China moisture and precipitation: Indian or East Asian monsoon?[J] J Geophys Res, 2012, 117: D12109. [24] 薛华星, 余锦华. 8月中国登陆台风降水与对流层高层西风急流关系的初步研究[J].热带气象学报, 2016, 32(5): 708-716. -
下载:
点击查看大图
图(12)
计量
- 文章访问数: 1535
- HTML全文浏览量: 95
- PDF下载量: 681
- 被引次数: 0
粤公网安备 4401069904700003号