The Influence of Sea Surface Temperature Anomaly on the East Asian Summer Monsoon Strength and Its Precursor
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摘要: 利用ERA-Interim再分析资料、NOAA海温资料、CMAP格点降水资料和中国气象站降水资料,通过合成、相关和回归分析等方法研究了1979—2012年东亚夏季风强度与其先兆信号的关系,并分析了热带海温异常的可能影响。研究表明:东亚夏季风先兆指数反映了2月200 hPa纬向风距平的主要模态特征 (EOF1),前冬热带中东太平洋海温偏低 (高),2月亚洲地区西风急流位置偏北 (偏南),东亚夏季风先兆指数偏强 (弱)。前期热带海温异常对东亚夏季风强度有明显影响,前冬热带中东太平洋海温偏低 (高) 有利于东亚夏季风偏强 (弱)。2月亚洲中纬度地区纬向风异常特征在春季不能持续,先兆信号与东亚夏季风强度的联系主要源自热带海洋。Abstract: The strength of the East Asian Summer Monsoon (EASM) is closely connected to the summer main rainfall belt in China. The precursor index defined by the difference of zonal wind anomaly at 200 hPa between the middle latitude in Asia and eastern Pacific in February is well indicative to the strength of EASM, which is an important predicting factors in flood season. The potential mechanism of precursor signal influencing the EASM is proposed by changing the surface characteristics in South Asia continent, but it is unclear whether the atmospheric circulation anomaly in February persists in the following seasons over middle latitude region.In addition, a further investigation is needed about the surface anomaly variation over South Asia in winter-spring seasons. ERA-Interim reanalysis data, NOAA sea surface data, gridded CMAP precipitation data and precipitation observations over China are used. By composite, correlation and regression analysis approaches, the difference of wind in middle latitude over Eurasia, sea surface temperature (SST) in tropics and thermal condition in South Asia continent in previous winter-spring seasons in various strength EASM years are analyzed. Results indicate that tropical SST is the physical connection of accordant variations between the strength of EASM and its precursor.Results show that the precursor signal of EASM captures the primary feature for the first mode of empirical orthogonal function (EOF1) of zonal wind anomaly at 200 hPa over the Asia and Pacific in February. The EOF1 mode is related to SST in the central and eastern Pacific. In the previous winter, the SST is below (above) normal in the central and eastern Pacific, which is conducive to a northward (southward) shift of westerly jet over the Asia in February. The zonal wind anomaly at 200 hPa exhibits meridional positive-negative-positive (negative-positive-negative) pattern, and the precursor index is stronger (weaker) than normal. In summer, the negative (positive) SST anomaly occurs in the vicinity of Indian Ocean and South China Sea, which results in an increasing (decreasing) difference between ocean and land and stronger (weaker) Indian Summer Monsoon. Meanwhile, the western Pacific subtropical high (WPSH) is weaker (stronger) than normal, and the EASM is stronger (weaker) than normal.The anomalous feature of zonal wind in the middle latitude of the Asia in February is hardly to persist in spring. The physical connection between EASM and its precursor mainly derives from the tropical ocean.
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Key words:
- EASM;
- precursor index;
- SST;
- rainfall belt
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图 3 东亚夏季风强、弱年2月200 hPa纬向风距平合成差异 (单位:m·s-1)
(粗实线表示200 hPa纬向风气候场50 m·s-1等值线,阴影表示达到0.1显著性水平)
Fig. 3 Composite difference of zonal wind anomaly (unit: m·s-1) at 200 hPa in February in different strength years of EASM
(the solid bold line denotes climatological 50 m·s-1 contour of zonal wind at 200 hPa, the shaded denotes the difference significant at 0.1 level)
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[1] 竺可桢.东南季风与中国之雨量.地理学报, 1934, 1(1):1-27. http://www.cnki.com.cn/Article/CJFDTOTAL-DLXB193401000.htm [2] 李崇银.大气季节内振荡研究的新进展.自然科学进展, 2004, 14(7):734-741. http://www.cnki.com.cn/Article/CJFDTOTAL-ZKJZ200407004.htm [3] 陈丽娟, 高辉, 龚振淞, 等.2012年汛期气候预测的先兆信号及其应用.气象, 2013, 39(9):1103-1110. doi: 10.7519/j.issn.1000-0526.2013.09.003 [4] 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.Int J Climatol, 2008, 28:1139-1161. doi: 10.1002/joc.v28:9 [5] 陶诗言.季风研究中有待解决的问题//现代大气科学前沿与展望.北京:气象出版社, 1996:35-36. [6] Mooley D A, Parthasarathy B.Fluctuation in all India summer monsoon rainfall during 1871-1985.Climate Change, 1984, 6:287-301. doi: 10.1007/BF00142477 [7] Parthasarathy B, Kumar R R, Kthawale D R.Indian summer monsoon rainfall indices, 1871-1990.Meteor Mag, 1992, 121:174-186. https://www.researchgate.net/publication/290693318_Indian_summer_monsoon_rainfall_indices_1871-1990 [8] 郭其蕴.东亚夏季风强度指数及其变化的分析.地理学报, 1983, 38(3):207-216. http://www.cnki.com.cn/Article/CJFDTOTAL-NJQX200404011.htm [9] Shi N, Zhu Q G.An abrupt change in the intensity of the East Asian summer monsoon index and its relationship with temperature and precipitation over East China.Int J Climatol, 1996, 16:757-764. doi: 10.1002/(ISSN)1097-0088 [10] Webster P J, Yang S.Monsoon and ENSO:Selectively interactive systems.Quar J Roy Meteor Soc, 1992, 118:877-926. doi: 10.1002/(ISSN)1477-870X [11] Wang B, Fan Z.Choice of South Asian summer monsoon indices.Bull Amer Meteor Soc, 1999, 80:629-638. doi: 10.1175/1520-0477(1999)080<0629:COSASM>2.0.CO;2 [12] 黄刚.东亚夏季风环流异常指数与夏季气候变化关系的研究.应用气象学报, 1999, 10(增刊Ⅰ):61-69. doi: 10.3969/j.issn.1001-7313.1999.02.014 [13] 张庆云, 陶诗言, 陈烈庭.东亚夏季风指数的年际变化与东亚大气环流.气象学报, 2003, 61(4):579-568. http://www.cnki.com.cn/Article/CJFDTOTAL-QXXB200305005.htm [14] Li J P, Zeng Q C.A unified monsoon index.Geophys Res Lett, 2002, 29:1274, doi: 10.1029/2001GL013874. [15] Wang H J.Instability of the East Asian summer monsoon ENSO relations.Adv Atmos Sci, 2002, 19:1-11. doi: 10.1007/s00376-002-0029-5 [16] 戴念军, 谢安, 张勇.南海夏季风活动的年际和年代际特征.气候与环境研究, 2000, 5:363-374. doi: 10.3878/j.issn.1006-9585.2000.04.04 [17] Wang B, Wu Z W, Li J P, et al.How to measure the strength of the East Asian summer monsoon.J Climate, 2008, 21:4449-4463. doi: 10.1175/2008JCLI2183.1 [18] Ding Y H, Sun Y, Wang Z Y, et al.Inter-decadal variation of the summer precipitation in China and its association with decreasing Asian summer monsoon Part Ⅱ:Possible causes.Int J Climatol, 2009, 29:1926-1944. doi: 10.1002/joc.v29:13 [19] Xie P, Arkin P A.A 17-year monthly analysis based on gauge observations, satellite estimates, and numerical model outputs.Bull Amer Meteor Soc, 1997, 78:2539-2558. doi: 10.1175/1520-0477(1997)078<2539:GPAYMA>2.0.CO;2 [20] Dee D P, Uppala S M, Simmons A J, et al.The ERA-Interim reanalysis:Configuration and performance of the data assimilation system.Quart J Roy Meteor Soc, 2011, 137:553-597. doi: 10.1002/qj.v137.656 [21] Smith T M, Reynolds R W, Peterson T C, et al.Improvements to NOAA's historical merged land-ocean surface temperature analysis (1880-2006).J Climate, 2008, 21:2283-2296. doi: 10.1175/2007JCLI2100.1 [22] 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, 19:1005-1017. https://www.researchgate.net/publication/258514280_Relations_of_Water_Vapor_Transport_from_Indian_Monsoon_with_That_over_East_Asia_and_the_Summer_Rainfall_in_China [23] Wei W, Zhang R H, Wen M, et al.Impact of Indian summer monsoon on the South Asian high and its influence on summer rainfall over China.Clim Dyn, 2014, 43:1257-1269. doi: 10.1007/s00382-013-1938-y [24] Zhang R H.Impact of El Nio on the East Asian monsoon:A diagnostic study of the '86/87 and '91/92 events.J Meteorol Soc Jpn, 1996, 74:49-62. doi: 10.2151/jmsj1965.74.1_49 [25] Wang B, Wu R G, Fu X.Pacific-East Asian teleconnection:How does ENSO affect East Asian climate? J Climate, 2000, 13:1517-1535. doi: 10.1175/1520-0442(2000)013<1517:PEATHD>2.0.CO;2 [26] Chang C P, Zhang Y, Li T.Interannual and interdecadal variations of the East Asian summer monsoon and tropical Pacific SSTs.Part Ⅰ:Role of the subtropical ridge.J Climate, 2000, 13:4310-4325. doi: 10.1175/1520-0442(2000)013<4310:IAIVOT>2.0.CO;2 [27] Chang C P, Zhang Y, Li T.Interannual and interdecadal variations of the East Asian summer monsoon and tropical Pacific SSSTs.Part Ⅱ:Meridional structure of the monsoon.J Climate, 2000, 13:4326-4340. [28] 李峰, 何立富.长江中下游地区夏季旱涝年际、年代际变化的可能成因研究.应用气象学报, 2002, 13(6):718-726. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20020694&flag=1 [29] 李秀萍, 罗勇, 郭品文, 等.春夏季中东太平洋海温异常变化与东亚夏季风关系的研究.应用气象学报, 2006, 17(2):176-182. doi: 10.11898/1001-7313.20060208 [30] 吕俊梅, 张庆云, 陶诗言, 等.东亚夏季风强弱年大气环流和热源异常对比分析.应用气象学报, 2007, 18(4):442-451. doi: 10.11898/1001-7313.20070404 [31] Wu B, Zhang R, Ding Y, et al.Distinct modes of the East Asian summer monsoon.J Climate, 2008, 21:1122-1138. doi: 10.1175/2007JCLI1592.1 [32] 陈丽娟, 袁媛, 杨明珠, 等.海温异常对东亚夏季风影响机理的研究进展.应用气象学报, 2013, 24(5):521-532. doi: 10.11898/1001-7313.20130502 [33] 张顺利, 陶诗言.青藏高原积雪对亚洲夏季风影响的诊断及数值研究.大气科学, 2001, 25(3):372-390. http://www.cnki.com.cn/Article/CJFDTOTAL-DQXK200103008.htm [34] Qian Y F, Zheng Y Q, Zhang Y, et al.Responses of China's summer monsoon climate to snow anomaly over the Tibetan Plateau.International Journal of Climatology, 2003, 23:593-613. doi: 10.1002/(ISSN)1097-0088 [35] 包庆, Wang Bin, 刘屹岷, 等.青藏高原增暖对东亚夏季风的影响--大气环流模式数值模拟研究.大气科学, 2008, 32(5):997-1005. http://www.cnki.com.cn/Article/CJFDTOTAL-DQXK200805000.htm [36] 薛峰.南半球环流变化对东亚夏季风的影响.气候与环境研究, 2005, 10(3):401-408. http://www.cnki.com.cn/Article/CJFDTOTAL-QHYH200503012.htm [37] 武炳义, 张人禾.东亚夏季风年际变率及其与中、高纬度大气环流以及外强迫异常的联系.气象学报, 2011, 69(2):219-233. doi: 10.11676/qxxb2011.019 [38] 唐佳, 武炳义.20世纪90年代初东亚夏季风的年代际转型.应用气象学报, 2012, 8(4):402-413. doi: 10.11898/1001-7313.20120403