南半球中纬度偶极模态与亚洲—非洲夏季降水

明静; 孙建奇; 李国平; 裴军林

doi:10.3878/j.issn.1006-9895.1409.14193

南半球中纬度偶极模态与亚洲—非洲夏季降水

doi: 10.3878/j.issn.1006-9895.1409.14193

1.
成都信息工程学院, 成都610225;中国科学院大气物理研究所竺可桢—南森国际研究中心, 北京100029
2.
中国科学院大气物理研究所竺可桢—南森国际研究中心, 北京100029
3.
成都信息工程学院, 成都610225
4.
西昌卫星发射中心, 西昌615000

基金项目: 公益性行业(气象)科研专项GYHY201306026, 中国科学院战略性先导科技专项XDA05090306, 中国科学院澳大利亚联邦科工组织战略合作项目GJHZ1223, 江苏省气候变化协同创新中心

计量
- 文章访问数: 2825
- HTML全文浏览量: 32
- PDF下载量: 2712
- 被引次数: 0
出版历程
- 收稿日期: 2014-07-16
- 修回日期: 2014-09-10

Dipole Pattern in Southern Hemispheric Mid-latitude and Asian-African Summer Precipitation

1.
Chengdu University of Information Technology, Chengdu 610225;Nansen-Zhu International Research Centre, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029
2.
Nansen-Zhu International Research Centre, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029
3.
Chengdu University of Information Technology, Chengdu 610225
4.
Xichang Satellite Launch Center, Xichang 615000

摘要

摘要: 南半球大气环流第一模态为南极涛动, 它表现出较好的纬向对称结构。本工作利用经验正交分解方法研究发现, 在南半球的东半球, 夏季(6~9月)大气环流还存在一个重要的模态。不同于南极涛动, 该模态表现为显著的纬向偶极分布, 本文定义其为偶极模态。在海平面气压场上, 该模态的解释方差可以达到20%以上, 表现出显著的年际变化特征。进一步的研究发现, 该偶极模态与亚非夏季降水存在密切联系, 尤其与我国华南、南亚以及热带非洲东部地区的夏季降水存在显著的正相关关系。机制分析表明, 南半球这一偶极模态的异常会影响东半球越赤道气流的变化, 从而造成向上述三个地区的水汽输送的多寡, 并最终导致这三个地区夏季降水发生变化。本工作揭示的偶极模态变化独立于南极涛动, 研究结果不但可以深化对南半球环流系统变化特征及影响的认识, 而且对亚非夏季降水的变化特征和机制研究也具有重要意义。
- 偶极模态 /
- 夏季降水 /
- 越赤道气流
Abstract: As the first middle and high latitude circulation mode in the Southern Hemisphere, the Antarctic Oscillation (AAO) has a zonally symmetric structure.Using the empirical orthogonal function method, this study reveals existence of another dominant mode of atmospheric circulation in the eastern Southern Hemisphere boreal summer (June-September).Different from the AAO, this mode shows a significant zonal dipole distribution, or dipole pattern.This dipole pattern accounts for more than 20% of the total variance in the regional sea-level pressure field, and shows a strong interannual variation.Further research has demonstrated that the dipole pattern is significantly positively correlated with summer rainfall in Asia and Africa, especially in South China, South Asia, and tropical eastern Africa.Analysis suggests this pattern anomaly can influence the variation of cross-equatorial flow in the Eastern Hemisphere, which can affect the transportation of water vapor into South China, South Asia, and tropical eastern Africa, and ultimately result in summer precipitation anomalies over the three regions.The dipole pattern revealed in this study is independent from the AAO, and the results of this study are not only helpful for better understanding the variation and influence of the atmospheric circulation in the Southern Hemisphere but also for examining summer precipitation variations and mechanisms in Africa and Asia.
- Dipole pattern /
- Summer precipitation /
- Cross-equator flow

HTML全文

参考文献(22)

[1]	Adler R F, Huffman G J, Chang A, et al.2003.The version-2 global precipitation climatology project (GPCP) monthly precipitation analysis (1979-present)[J].J.Hydrometeor., 4 (6):1147-1167.
[2]	陈隆勋.1984.东亚季风环流系统的结构及其中期变动[J].海洋学报, 6 (6):744-758.Chen Longxun.1984.Structure of the East Asian monsoon system and its medium-range oscillation[J].Acta Oceanologica Sinica (in Chinese), 6(6):744-758.
[3]	陈于湘.1980.夏季西太平洋越赤道气流的谱分析[J].大气科学, 4 (4):363-368.Chen Yuxiang.1980.The spectral analysis of the low-level cross-equator air flow over the western Pacific during the northern summer[J].Chinese Journal of Atmospheric Sciences (in Chinese), 4 (4):363-368.
[4]	Dee D P, Uppala S M, Simmons A J, et al.2011.The ERA-Interim reanalysis:Configuration and performance of the data assimilation system[J].Quart.J.Roy.Meteor.Soc., 137 (656):553-597.
[5]	Fan K, Wang H J.2004.Antarctic oscillation and the dust weather frequency in North China[J].Geophys.Res.Lett., 31:L10201, doi:10.1029/ 2004GL019465.
[6]	Findlater J.1969.A major low-level air current near the Indian Ocean during the northern summer[J].Quart.J.Roy.Meteor.Soc., 95 (404):362-380.
[7]	高辉, 薛峰, 王会军.2003.南极涛动年际变化对江淮梅雨的影响及预报意义[J].科学通报, 48 (S2):87-92.Gao Hui, Xue Feng, Wang Huijun.2003.Influence of interannual variability of Antarctic Oscillation on Meiyu along the Yangtze and Huaihe River valley and its importance to prediction[J].Chinese Science Bulletin (in Chinese), 48 (S2):87-92.
[8]	黄士松, 汤明敏.1987.论东亚夏季风体系的结构[J].气象科学, (3):1-14.Huang Shisong, Tang Mingmin.1987.On the structure of the summer monsoon regime of East Asia[J].Scientia Meteorologica Sinica (in Chinese), (3):1-14.
[9]	李宪之.1956.台风生成的综合学说[J].气象学报, 27 (2):87-100.Li Xianzhi.1956.Comprehensive theory of typhoon genesis[J].Acta Meteorologica Sinica (in Chinese), 27 (2):87-100.
[10]	Sun J Q, Wang H J, Yuan W.2009.A possible mechanism for the co-variability of the boreal spring Antarctic Oscillation and the Yangtze River valley summer rainfall[J].Int.J.Climatol., 29 (9):1276-1284.
[11]	Sun J Q.2010.Possible impact of the boreal spring Antarctic Oscillation on the North American summer monsoon[J].Atmos.Oceanic Sci.Lett., 3 (4):232-236.
[12]	Sun J Q, Wang H J, Yuan W.2010.Linkage of the boreal spring Antarctic Oscillation to the West African summer monsoon[J].J.Meteor.Soc.Japan, 88 (1):15-28.
[13]	汤明敏, 黄士松, 周德佩.1985.全球越赤道气流的时空变化[J].热带气象, (4):287-296.Tang Mingmin, Huang Shisong, Zhou Depei.1985.On the spatial and temporal variation of the cross-equatorial currents around the globe[J].Journal of Tropical Meteorology (in Chinese), (4):287-296.
[14]	陶诗言, 徐淑英, 郭其蕴.1962.夏季东亚热带和副热带地区经向和纬向环流型的特征[J].气象学报, 32 (2):91-103.Tao Shiyan, Xu Shuying, Guo Qiyun.1962.The characteristics of the zonal and meridional circulation over tropical and subtropical regions in eastern Asia in summer[J].Acta Meteorologica Sinica (in Chinese), 32 (2):91-103.
[15]	王会军, 薛峰.2003.索马里急流的年际变化及其对半球间水汽输送和东亚夏季降水的影响[J].地球物理学报, 46 (1):18-25.Wang Huijun, Xue Feng.2003.Interannual variability of Somali jet and its influences on the inter-hemispheric water vapor transport and on the East Asian summer rainfall[J].Chinese Journal of Geophysics (in Chinese), 46 (1):18-25.
[16]	王会军, 范可.2006.西北太平洋台风生成频次与南极涛动的关系[J].科学通报, 51 (24):2901-2914.Wang Huijun, Fan Ke.2007.Relationship between the Antarctic oscillation in the western North Pacific typhoon frequency[J].Chinese Science Bulletin, 52 (4):561-565.
[17]	Wang H J, Fan K.2005.Central-North China precipitation as reconstructed from the Qing Dynasty:Signal of the Antarctic Atmospheric Oscillation[J].Geophy.Res.Lett., 32:L24705, doi: 10.1029/2005GL024562.
[18]	王兴东, 陶诗言.1984.西太平洋越赤道气流的初步研究[J].海洋学报, 6 (2):160-173.Wang Xingdong, Tao Shiyan.1984.The preliminary study on the cross-equatorial flow over the western Pacific[J].Acta Oceanologica Sinica (in Chinese), 6 (2):160-173.
[19]	薛峰, 王会军, 何金海.2003.马斯克林高压和澳大利亚高压的年际变化及其对东亚夏季风降水的影响[J].科学通报, 48 (3):287-291.Xue Feng, Wang Huijun, He Jinhai.2003.Interannual variability of Mascarene high and Australian high and their influences on summer rainfall over East Asia[J].Chinese Science Bulletin, 48 (5):492-497.
[20]	Xue F, Wang H J, He J H.2004.Interannual variability of Mascarene high and Australian high and their influences on East Asian Summer Monsoon[J].J.Meteor.Soc.Japan, 82 (4):1173-1186.
[21]	薛峰, 何卷雄.2005.南半球环流变化对西太平洋副高东西振荡的影响[J].科学通报, 50 (15):1660-1662.Xue Feng, He Juanxiong.2005.Influence of the southern hemispheric circulation on east-west oscillation of the western subtropical high[J].Chinese Science Bulletin, 50 (14):1532-1536.
[22]	薛峰.2005.南半球环流变化对东亚夏季风的影响[J].气候与环境研究, 10 (3):401-408.Xue Feng.2005.Influence of the southern circulation on East Asian summer monsoon[J].Climatic and Environmental Research (in Chinese), 10 (3):401-408.赵宗慈, 王绍武.1979.南北半球大气环流与气候的相互作用[J].气象学报, 37 (2):58-68.Zhao Zongci, Wang Shaowu.1979.Interactions between the circulation and climate in Northern and Southern Hemispheres[J].Acta Meteorologica Sinica (in Chinese), 37 (2):58-68.