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| 1948～2004年全球越赤道气流气候变化 |
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施能1,2, 封国林3, 顾骏强4, 谷德军2
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1.南京信息工程大学, 气象灾害和环境变化重点实验室, 江苏, 南京, 210044;2.中国气象局广州热带海洋气象研究所, 广东, 广州, 510080;3.国家气候中心气候研究开放实验室, 北京, 100081;4.浙江省气象科学研究所, 浙江, 杭州, 310017
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| 摘要: |
| 利用1948年1月～2004年12月逐月NCEP/NCAR的全球1000hPa、850hPa、700hPa、600hPa、500hPa、400hPa、300hPa、200hPa、150hPa、100hPa的10层经向格点风,计算了全球越赤道气流和年变化,分析了全球850hPa越赤道气流通道的时、空变化特征。指出在研究的时间段内,全球850hPa越赤道气流有明显的长期趋势变化和年代际变化。近57年,6～8月的45～50°E、5～9月的105～115°E、5～9月和5～11月的130～140°E、2～4月的20～25°E的越赤道气流有明显的加强,6～8月的50～35°W的越赤道气流减弱。夏季索马里的越赤道气流,平均每10年增强0.25m/s,而130～140°E,5～9月的越赤道气流,平均每10年增强0.32m/s。奇异谱分析表明,850hPa越赤道气流的年代际变化和趋势变化的方差贡献达到35%～45%。年际变化的方差贡献不超过30%,还指出夏季太平洋的越赤道气流的强度变化与南方涛动有明显关系,弱南方涛动时,有强的越赤道气流。而索马里急流强度与北大西洋涛动有弱的正相关。 |
| 关键词: 越赤道气流 气候变化 趋势 奇异谱分析 南方涛动 |
| DOI： |
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| 基金项目:国家自然科学基金(40275018,90411008);热带海洋气象科学研究基金;中国气象局热带季风重点开放实验室共同资助 |
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| THE CLIMATOLOGICAL VARIATION OF GLOBAL CROSS-EQUATORIAL FLOW FOR THE PERIOD OF 1948～2004 |
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SHI Neng1,2, FENG Guo-lin3, GU Jun-qiang4, GU De-jun2
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1.Key Laboratory of Meteorology Disaster and Environment Variation, Nanjing University of Information Science and Technology, Nanjing 210044, China;2.Institute of Tropical and Marine Meteorology, CMA, Guangzhou 510080, China;3.Key Laboratory of National Meteorological Bureau Climate Research Center, Beijing 100081, China;4.Zhejiang Meteorological Science Research Institute, Hangzhou 310017, China
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| Abstract: |
| By using monthly NCEP/NCAR meridional gridpoint wind data at the levels of 1000,850,700,600,500,400,300,200,150 and 100hPa from 1948 to 2004,the intensity of global cross-equatorial flow is calculated.The spatial and temporal variation of global cross-equatorial flows at the 850hPa level are shown and discussed.The results show that the strength of the 850hPa global cross-equatorial flows represent obviously long-term variation and interdecadal change during the period.Evidence suggests that the cross-equatorial flow of the passages at 45～50°E in June to August,105～115°E in May to September,130～140°E in May to September and May to November and 20～25°E in February to April intensified and that the cross-equatorial flow of the passages at 50～35°W in June to August weaken in the past 57 years,with an increase of 0.25m/s/10a for summer Somali cross-equatorial flow and increase of 0.32 m/s/10a for cross-equatorial flow at 130～140°E in May to September.The results of Singular Spectrums Analysis(SSA) for the time series of cross-equatorial flow indicate that for the cross-equatorial flow at 850 hPa,the interdecadal and long-term trend changes have 35%～45%,and the interannual variation has no more than 30%,in variance contribution.The results also reveal that the interannual variation of intensity of the cross-equatorial flow in summer in the Pacific has significantly correlated with Southern Oscillation.With weak Southern Oscillation,strong Cross-equatorial flow in Pacific will happen.But summer Somali Jet only has little positive correlation with NAO. |
| Key words: Cross-equatorial flow climatic change trend change Singular Spectrums analysis Southern Oscillation |