| 冬季北太平洋南北海温异常对我国汛期雨带类型的影响研究 |
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| 引用本文： | 杨素雨,严华生.冬季北太平洋南北海温异常对我国汛期雨带类型的影响研究[J].应用气象学报,2007,18(2):193-201. |
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| 作者姓名： | 杨素雨 严华生 |
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| 作者单位： | 1.云南省气象台, 昆明 650034 |
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| 基金项目： | 国家自然科学基金;云南省重点项目 |
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| 摘 要： | 使用1951—2002年前期（1—5月）北太平洋海温场月平均资料，运用合成分析、多因变量方差分析、判别分析及相关分析方法，探讨我国汛期雨带类型与前期北太平洋海温的时空分布关系。分析表明:尽管汛期各雨带类型对应着前期不同的海温距平场，但它们之间只有部分海域存在显著性差异，且在1月表现最显著。各雨带类型对应海温距平场显著差异关键区主要位于北太平洋的南北海域，即北部中高纬亲潮附近（40°~50°N, 160°E~180°），北太平洋西风漂流区（30°~40°N，175°~145°W）及南部近赤道太平洋中部（10°S~0°, 175°~145°W），且南北海温呈反相关关系。将海温关键区作为判别因子，对雨带类型进行判别分析表明:用多个海温关键区作为判别因子建立的判别方程，其判别准确率比仅用某一海温关键区或海温区之间的和差简单定义的指数作为判别因子建立的判别方程判别准确率高，说明我国东部汛期降水型的分布与多个海温关键区的综合作用是密切相关的。进一步分析判别方程定义的1月海温判别指数与前期高度场和夏季副热带高压各特征量的相关关系表明，该指数对我国汛期雨带类型影响的可能途径是:一是造成大气环流异常，特别是北太平洋涛动的异常，并形成PNA大气遥相关型，从而引起我国汛期降水异常；二是造成西太平洋副热带高压的异常，主要是面积、强度和西伸脊点位置的异常，从而引起我国汛期降水异常。可见，冬季北太平洋海温南北异常与我国汛期雨带类型关系密切，且具有重要的天气气候学意义。
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| 关 键 词： | 雨带类型 海温场 显著关键区 大气环流 |
| 收稿时间： | 2005-11-21 |
| 修稿时间： | 2006-10-10 |
Impact of the North and South SSTA in North Pacific on Rainfall Patterns of Flood Season in China |
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| Yang Suyu Yan Huasheng.Impact of the North and South SSTA in North Pacific on Rainfall Patterns of Flood Season in China[J].Quarterly Journal of Applied Meteorology,2007,18(2):193-201. |
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| Authors: | Yang Suyu Yan Huasheng |
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| Affiliation: | 1.Meteorological Observatory of Yunnan Province, Kunming 6500342.Department of Atmospheric Science, Yunnan University, Kunming 650091 |
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| Abstract: | Based on the data of monthly mean SST of the North Pacific Ocean by National Climate Center during 1951—2002, the analytical methods of composite analysis and multi variable factors variance and also the method of correlation analysis for the relationship of the summer east China rainfall patterns and the SSTA of south and north in North Pacific Ocean are applied. It is found that the rainfall patterns have a close relation to the SSTA of North Pacific Ocean during the previous period from January to May. Though the distribution of rainfall patterns in rainy season is connected with different previous SSTA composite fields, there are only some key areas in the north and the south that can pass the significant test level in previous period, especially in preceding January. The key areas in north and south which have close negative correlation lie on the neighborhood of the extratropical Oyashio (40°—50°N, 160°E—180°), the West Wind Drift field (30°—40°N, 175°—145°W) and the middle part of The North Pacific Ocean in equator (10°S—0°, 175°—145°W) respectively. When the SST of key areas are regarded as the discrimination factors, the discrimination analysis of rainfall pattern shows that the discrimination accuracy of discriminating equation set up by regarding more key areas as discrimination factors is higher than the discriminating equation set up by regarding only one key area or the SST index defined by regarding the composite of some SST areas as discrimination factors. Those are the summer east China rainfall patterns which have a close connection with the synthetic effect of more SST areas. Further research on the correlation coefficients between eigenvalues of summer 500 hPa western Pacific subtropical high and the geopotential height of 500 hPa in the preceding January. and the SST index defined by discriminating equation in the preceding January. indicates that there are two possible ways of how the SST discriminating index affect the rainfall patterns of flood season in China. On one hand the atmospheric circulation anomaly is brought, especially the North Pacific Oscillation anomalies, and the PNA atmospheric teleconnection associate is given, then the summer east China precipitation is affected. On the other hand, it leads to the anomalies of eigenvalues of summer 500 hPa western Pacific subtropical high, especially the anomalies of the proportions, intension and westward ridge point of subtropical high. As a result the summer east China precipitation is affected. It is obvious that the SST anomalies in preceding January of the north and the south in North Pacific Ocean have a very close connection with the summer east China rainfall patterns, and it has important synoptic climatological significance. |
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| Keywords: | rain pattern SST significant key region atmospheric circulation |
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