Inter-decadal Variations of Summer Water Budgets in the Monsoon Wetness Region of Eastern China
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摘要: 采用1983—2002年NCEP/NCAR再分析资料和我国660站降水资料,对我国东部季风湿润区夏季水汽收支变化与大气环流和我国降水异常特征的关系进行研究。结果表明:20世纪80—90年代夏季水汽收支时间序列表现出明显的年代际变化增加趋势,与降水时间序列的相关系数为0.71;水汽收支高值、低值年代不仅能够指示季风湿润区经向风的异常变化,还能够指示东亚夏季风的强弱和降水异常变化。合成的水汽输送年代际异常在东亚—西太平洋区表现为4个异常环流,异常水汽通量辐合区位于长江流域及以南地区。水汽收支高值年代,亚洲大陆高纬度地区低压偏弱,大陆表面温度及西太平洋海温偏高,我国东部沿海盛行异常偏南风,低层气流辐合、高层气流辐散强,垂直上升运动强烈;低值年代则相反。合成的经向水汽收支占总收支的71.3%,合成的异常降水量最大达100 mm以上。Abstract: Using monthly means of NCAR/ NCEP reanalysis datasets and rainfall data from 660 surface stations in China, a water budgets time series over the monsoon wetness region in Eastern China is calculated by a water vapor transport method for the period from 1983 to 2002, referring to changes in inter-decadal variability of water budgets associated with the anomalous atmospheric circulations and precipitation in the monsoon wetness region of Eastern China. Relationships between the water budget index and the variability of the atmospheric circulation and rainfall in China are examined. The results show that the summer water budget time series displays the variability on the inter-decadal scale from the 1980s to the 1990s in the region. The correlation coefficient is 0.71 between the water budgets and regional average precipitation and decreases to 0.55 after removing the trends. The index reflects the variations of the meridional winds anomalies and indicates an intensity of summer monsoon and an anomaly of rainfall along the valleys in the monsoon wetness region of Eastern China. The anomalous water vapor transport is affected by four anomalous circulations: The anomalous cyclonic circulation between 20°N and 30°N over the Eastern China, and the anomalous anti-cyclonic circulations between 40°N and 60°N over East Asian continent, between 18°N and 30°N over the west Pacific, and between 5°N and 20°N over the Bay of Bengal. Anomalous moisture flux convergence appears in the south of the Yangtze. Corresponding to the higher-index value decades, the low pressure centering in Mongolia is weaker and the surface temperature, sea surface temperature, the convergence in lower troposphere and divergence in upper troposphere are generally stronger in East Asia and the western north Pacific. Meanwhile, the southerly wind anomalies are prevailing in the eastern coast of China. This anomaly intensifies upward motion over the south mainland of China and drives the water vapor transport from South China Sea, and increases the water budgets and precipitation, with the difference of rainfall above 100 mm in the southern China. The water budgets are net surplus though uneven from 1983 to 2002. Vapor income in the low value year is about 24.3% less than in the high value year, and the precipitation is less by 18%. The anomalous meridional water budget is larger than zonal one, accounting for 71.3% of net budget. The anomalous water budget of low-index value decades accounts for 7% in latitude and 24% in longitude relative to the high-index value decades. The variation of the meridional water budget is larger than zonal one and is greater in magnitude. Therefore, the net water budget is quite different between high and low value decades of water budget and the anomalous precipitation is also significantly different.
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Key words:
- water budget;
- rainfall;
- atmospheric circulation;
- inter-decadal variability
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图 2 1983—2002年季风湿润区夏季标准化水汽收支和区域平均降水的时间序列
(点线为在1983—1992年和1993—2002年平均的标准化降水)(a) 以及水汽收支的M-K检验统计量曲线 (直线为达到0.001显著性水平线)(b)
Fig. 2 The normalized temporal curves of the water budgets and regional mean rainfall in the monsoon wetness region during summer from 1983 to 2002
(the dotted line represents the averages of the standardized precipitation over 1983—1992 and 1993—2002, respectively)(a) and the statistic curve of the M-K test for water budgets (the straight line represents the 0.001 level)(b)
图 3 夏季季风湿润区水汽收支高值、低值年代合成降水量及夏季季风湿润区降水与整层水汽通量散度相关分布
(阴影区表示达到0.1显著性水平) (a) 降水量差值 (高值减低值;单位:mm),(b)1983—2002年降水量标准差 (单位:mm),(c) 降水量与整层水汽通量散度相关分布
Fig. 3 Composite difference of summer precipitation between high and low value decades of water budgets and the correlations between regional mean precipitation and the divergence of vertically integrated water vapor flux in the monsoon wetness region
(the shaded denotes passing test of 0.1 level)(a) the composite difference of summer precipitation (high minus low; unit: mm), (b) the standard deviation of summer precipitation during 1983—2002(unit: mm), (c) correlations between regional mean precipitationand the divergence of vertically integrated water vapor flux
图 4 夏季季风湿润区水汽收支高值和低值年代合成的整层水汽通量和水汽通量散度差值 (阴影区表示达到0.1显著性水平)
(a) 水汽通量 (单位:kg·m-1·s-1), (b) 水汽通量散度 (单位:mm·d-1)
Fig. 4 Composite difference of vertically integrated water vapor flux and its convergence between high and low value decades of water budget in the monsoon wetness region (the shaded denotes passing the test of 0.1 level)
(a) water vapor flux (unit: kg·m-1·s-1), (b) divergence of water vapor flux (unit: mm·d-1)
图 5 夏季季风湿润区水汽收支高值和低值年代合成的表面气温差值 (单位:℃)(a)、表面气压 (等值线,单位:hPa) 及风场 (矢量) 差值 (b)、海表温度差值 (单位:℃)(c)(阴影区表示达到0.1显著性水平; 粗虚线为1500 m高度)
Fig. 5 Composite difference of summer surface temperature monsoon wetness region (unit: ℃)(a), the surface pressure (isoline, unit:hPa) and wind (vector)(b) and SST (unit:℃)(c) (the shaded denotes passing the test of 0.1 level; the thick dashed line denotes the height of 1500 m)
图 6 夏季季风湿润区水汽收支高值和低值年代合成的100 hPa风场 (单位:m·s-1)(a)、300 hPa辐散场 (单位:107s-1)(b)、500 hPa位势高度场 (单位:gpm)(c) 和850 hPa风场 (单位:m·s-1)(d) 的差值分布
(阴影区表示达到0.1显著性水平;黑色区域表示地形)
Fig. 6 Composite difference of summer wind at 100 hPa (unit: m·s-1)(a), wind divergence at 300 hPa (unit:107s-1)(b), geopotential height at 500 hPa (unit: gpm)(c) and wind at 850 hPa (unit: m·s-1)(d) in the monsoon wetness region
(the shaded denotes passing the test of 0.1 level; the black area denotes terrain)
图 7 夏季季风湿润区水汽收支高和低值年代合成的300 hPa (单位:10-6kg·m-2·s-1)(a)、850 hPa (b) 水汽通量散度差值分布 (单位:10-5kg·m-2·s-1)、300 hPa (c)、850 hPa (d) 假相当位温差值分布 (单位:K)(阴影区表示达到0.1显著性水平; 黑色区域表示地形)
Fig. 7 Composite difference of summer water vapor flux divergence at 300 hPa (unit: 10-6kg·m-2·s-1)(a) and 850 hPa (b)(unit: 10-5kg·m-2·s-1), pseudo-equivalent temperature (unit: K) at 300 hPa (c) and 850 hPa (d)(unit: K) in the monsoon wetness region (the shaded denotes passing the test of 0.1 level; the black area denotes terrain)
图 8 夏季季风湿润区水汽收支高值和低值年代合成的22°~30°N平均 (a)、110°~120°E平均 (b) 的垂直环流 (矢量; u,v单位:m·s-1;w单位:10-2 Pa·s-1,w扩大2倍) 和假相当位温 (等值线,单位:K) 差值分布
(阴影区表示达到0.1显著性水平; 黑色区域表示地形)
Fig. 8 Composite difference of summer 22°—30°N average (a) and 110°—120°E average (b) of vertical circulation (vector; unit of u, v: m·s-1; unit of w:10-2 Pa·s-1, w is expanded by 2 times) and pseudo-equivalent temperature (isoline, unit: K) in the monsoon wetness region
(the shaded denotes passing the test of 0.1 level; the black area denotes terrain)
表 1 我国东部季风湿润区夏季高值、低值年代水汽收支及区域平均降水量距平及其差值
Table 1 Composite values of the summer water budgets and precipitation between high and low value decades in the monsoon wetness region of Eastern China with their differences
距平 高值年代 低值年代 差值 经向水汽收支
/(104m3·s-1)5.8 -0.4 6.2 纬向水汽收支
/(104m3·s-1)-3.3 -0.8 -2.5 水汽净收支
/(104m3·s-1)2.5 -1.2 3.7 降水量/mm 18.1 -14.4 32.5 -
[1] Rasmusson E M. Atmospheric water vapor transport and the water balance of North America. Part Ⅰ: Characteristics of the water vapor flux field. Mon Wea Rev, 1967, 95:403-426. doi: 10.1175/1520-0493(1967)095<0403:AWVTAT>2.3.CO;2 [2] Rasmusson E M, Mo K C. Large-scale atmospheric moisture cycling as evaluated from NMC global analysis and forecast products. J Climate, 1996, 9:3276-3297. doi: 10.1175/1520-0442(1996)009<3276:LSAMCA>2.0.CO;2 [3] Roads J O, Chen S C, Guetter A K, et al. Large-scale aspects of the United States hydrological cycle. Bull Amer Meteor Soc, 1994, 75: 1589-1610. doi: 10.1175/1520-0477(1994)075<1589:LSAOTU>2.0.CO;2 [4] Simmonds Ⅰ, Daohua Bi, Hope P. Atmospheric water vapor flux and its association with rainfall over China in summer. J Climate, 1999, 12(5):1353-1367. doi: 10.1175/1520-0442(1999)012<1353:AWVFAI>2.0.CO;2 [5] Ninomiya K. Moisture balance over China and the South China Sea during the summer monsoon in relation to the intense rain-falls over China. J Meteor Soc Japan, 1999, 77(3): 737-751. doi: 10.2151/jmsj1965.77.3_737 [6] Bisselink B, Dolman A J. Precipitation recycling: Moisture sources over Europe using ERA-40 data. J Hydrometeorology, 2008, 9(5):1073-1083. doi: 10.1175/2008JHM962.1 [7] Liu J, Stewart R E. Water vapor fluxes over the Saskatchewan river basin. J Hydrometeorology, 2003, 4(5):944-959. doi: 10.1175/1525-7541(2003)004<0944:WVFOTS>2.0.CO;2 [8] Draper C, Mills G. The atmospheric water balance over the semiarid Murray-Darling River Basin. J Hydrometeorology, 2008, 9(3):521-534. doi: 10.1175/2007JHM889.1 [9] Munoz E, Busalacchi A, Nigam S, et al. Winter and summer structure of the Caribbean low-level jet. J Climate, 2008, 23(2):987-1003. http://www.atmos.umd.edu/~nigam/Munoz.et.al.JCLIM.March.2008.pdf [10] Arraut J M, Satyamurty P. Precipitation and water vapor transport in the southern hemisphere with emphasis on the south American region. J Climate Appl Meteor, 2009, 48(9):1902-1912. doi: 10.1175/2009JAMC2030.1 [11] Knippertz P, Wernli H. A lagrangian climatology of tropical moisture exports to the northern hemispheric extratropics. J Climate, 2010, 21(15):1260-1268. doi: 10.1175/2009JCLI3333.1 [12] Schäfler A, Dörnbrack A, Kiemle C, et al. Tropospheric water vapor transport as determined from airborne lidar measurements. J Atmos Ocean Technol, 2010, 27:2017-2030. doi: 10.1175/2010JTECHA1418.1 [13] Sohn B J, Park S C. Strengthened tropical circulations in past three decades inferred from water vapor transport. J Geophys Res, 2010, 115, D15112, doi: 10.1029/2009JD013713. [14] 叶笃正, 黄荣辉.长江黄河流域旱涝规律和成因研究.济南:山东科学技术出版社, 1996. http://www.cnki.com.cn/Article/CJFDTOTAL-SYQY201603027.htm [15] 黄荣辉, 张振洲, 黄刚, 等.夏季东亚季风区水汽输送特征及其与南亚季风区水气输送的差别.大气科学, 1998, 22 (4):460-469. http://www.cnki.com.cn/Article/CJFDTOTAL-DQXK804.007.htm [16] Kwon M H, Jhun J G, Wang B, et al. Decadal change in relationship between east Asian and WNP summer monsoons. Geophys Res Lett, 2005, 32, L16709, doi: 10.1029/2005GL023026. [17] Kwon M H, Jhun J G, Ha K J. Decadal change in east Asian summer monsoon circulation in the mid-1990s. Geophys Res Lett, 2007, 34, L21706, doi: 10.1029/2007GL031977. [18] Yao C, Yang S, Qian W, et al. Regional summer precipitation events in Asia and their changes in the past decades. J Geophys Res, 2008, 113, D17107, doi: 10.1029/2007JD009603. [19] Wu R G, Wen Z P, Yang S, et.al. An interdecadal change in Southern China rainfall around 1992/1993. J Climate, 2010, 23(1):2389-2403. doi: 10.1175/2009JCLI3336.1 [20] He Jinhai, Sun Chenghu, Liu Yunyun, et al. Seasonal transition feature of large-scale moisture transport in the Asian-Australian monsoon region. Adv Atmos Sci, 2007, 24(1):1-14. doi: 10.1007/s00376-007-0001-5 [21] Zhang R H. Relations of water vapor transport from Indian Monsoon with that over East-Asia and the summer rainfall in China. Adv Atmos Sci, 2001, 18(5):1005-1017. http://en.cnki.com.cn/Article_en/CJFDTOTAL-DQJZ200105029.htm [22] 徐祥德, 陈联寿, 王秀荣, 等.长江流域梅雨带水汽输送源-汇结构.科学通报, 2003, 48(21):2288-2294. doi: 10.3321/j.issn:0023-074X.2003.21.015 [23] Zhou T J, Yu R C. Atmospheric water vapor transport associated with typical anomalous summer rainfall patterns in China. J Geophys Res, 2005, 110, D08104, doi: 10.1029/2004JD005413. [24] 赵瑞霞, 吴国雄.黄河流域中上游水分收支以及再分析资料可用性分析.自然科学进展, 2006, 16(3):316-324. http://www.cnki.com.cn/Article/CJFDTOTAL-ZKJZ200603012.htm [25] 赵瑞霞, 吴国雄.长江流域水分收支以及再分析资料可用性分析.气象学报, 2007, 65(3):416-427. doi: 10.11676/qxxb2007.039 [26] 简茂球, 陈蔚翔, 乔云亭, 等.广东大尺度大气水汽汇的年际及年代际变化特征.热带气象学报, 2007, 23(6):545-552. http://www.cnki.com.cn/Article/CJFDTOTAL-RDQX200706003.htm [27] 周长艳, 蒋兴文, 李跃清, 等.高原东部及邻近地区空中水汽资源的气候变化特征.高原气象, 2009, 28(1):55-63. http://cpfd.cnki.com.cn/Article/CPFDTOTAL-ZGQX200811003096.htm [28] 丁一汇, 孙颖, 李跃凤, 等. 20世纪90年代东亚严重旱涝事件的大尺度条件分析//我国旱涝重大气候灾害及其形成机理研究. 北京: 气象出版社, 2003: 260-275. [29] Ding Y H, 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. International Journal of Climatology, 2008, 28: 1139-1161. doi: 10.1002/joc.v28:9 [30] 施小英, 施晓晖, 毛嘉富.夏季东亚地区水汽输送年代际变化特征及其对中国东部降水的影响.地理学报, 2009, 64(7):861-870. doi: 10.11821/xb200907010 [31] 施小英, 施晓晖.夏季青藏高原东南部水汽收支气候特征及其影响.应用气象学报, 2008, 19(1):41-46. doi: 10.11898/1001-7313.20080108 [32] 陈际龙, 黄荣辉.亚洲夏季风水汽输送的年际年代际变化与中国陆地旱涝的关系.地球物理学报, 2008, 51(2):352-359. http://www.cnki.com.cn/Article/CJFDTOTAL-DQWX200802008.htm [33] 廖荣伟, 赵平.东亚季风湿润区水分收支的气候特征.应用气象学报, 2010, 21(6):649-658. doi: 10.11898/1001-7313.20100602 [34] 廖荣伟, 赵平.季风湿润区冬季水分收支的气候特征.应用气象学报, 2011, 22(6):641-653. doi: 10.11898/1001-7313.20110601 [35] 廖荣伟. 中国东部季风湿润区大气水分收支特征的研究. 北京: 中国科学院研究生院, 2011. [36] 武麦凤, 王旭仙, 孙健康, 等. 2003年渭河流域5次致洪暴雨过程的水汽场诊断分析.应用气象学报, 2007, 18(2):225-231. doi: 10.11898/1001-7313.20070238 [37] 叶晨, 王建捷, 张文龙.北京2009年"1101"暴雪的形成机制.应用气象学报, 2011, 22(4):398-410. doi: 10.11898/1001-7313.20110402 [38] Huang R H, Zhou L T, Chen W. The progresses of recent studies of the variabilities of the East Asian monsoon and their causes. Adv Atmos Sci, 2003, 20:55-69. doi: 10.1007/BF03342050 [39] Yanai M, Esbensen S, Chu J H. Determination of average bulk properties of tropical cloud clusters from larger-scale heat and moisture budgets. J Atmos Sci, 1973, 30(4):611-627. doi: 10.1175/1520-0469(1973)030<0611:DOBPOT>2.0.CO;2 [40] 武炳义, 张人禾, Rosanne D A.北极偶极子异常与中国东北夏季降水.科学通报, 2008, 53(12):1422-1428. doi: 10.3321/j.issn:0023-074X.2008.12.011 [41] Wu B Y, Zhang R H, Rosanne D A. Arctic dipole anomaly and summer rainfall in Northeast China. Chinese Science Bulletin, 2008, 53(14):2222-2229. https://www.researchgate.net/profile/Renhe_Zhang/publication/225612299_Arctic_dipole_anomaly_and_summer_rainfall_in_Northeast_China/links/0f3175351319122565000000.pdf?inViewer=true&disableCoverPage=true&origin=publication_detail [42] 张人禾, 武炳义, 赵平, 等.中国东部夏季气候20世纪80年代后期的年代际转型及其可能成因.气象学报, 2008, 66(5):697-706. doi: 10.11676/qxxb2008.064