杨秋明. 2001. 长江下游旱涝与夏半年欧亚环流30~60天振荡的年际变化[J]. 气象学报, 59(3):318-326, doi:10.11676/qxxb2001.033
长江下游旱涝与夏半年欧亚环流30~60天振荡的年际变化
THE DROUGHT/FLOOD IN THE LOW REACHES OF YANG-TZE RIVER AND THE INTERANNUAL VARIATIONS OF THE 30-60 DAY OSCILLATION OF EURASIAN CIR-CULATION DURING SUMMER HALF YEAR
投稿时间:1999-09-14  修订日期:1999-04-03
DOI:10.11676/qxxb2001.033
中文关键词:  长江下游旱涝  低频振荡强度  年际变化  对比函数分析  非线性
英文关键词:Drought/flood in the low reaches of Yangtze River  LFO intensity  Interannual variation  Contrast function analysis (CFA)  Nonlinearity
基金项目:
作者单位
杨秋明 江苏省气象台, 南京, 210008 
摘要点击次数: 1766
全文下载次数: 2015
中文摘要:
      对25a(1971~1995年)逐候东半球热带外500hPa高度距平场进行小波分析和旋转主成分分析,研究了30~60d低频振荡的时空变化及其与长江下游夏季旱涝和暴雨频数年际变化的关系。结果表明:6~10月欧亚型(EU)低频振荡强度与长江下游暴雨频数成显著负相关,同时,提出了能揭示变量间非线性关系的对比函数分析(CFA)方法,发现当5~8月西太平洋型(WP)低频流型偏强时,长江下游暴雨频数增加,容易发生洪涝;反之,无明显影响。仅当前期3~5月南亚大陆型偏强时长江下游降水量偏少,而3~5月南亚大陆型偏弱时暴雨频数明显增加。因此,长江下游旱涝与低频流型异常之间同时存在线性和非线性相关。
英文摘要:
      The relat ionships between the interannual variations on the intensity of LFO(30-60 days) of Eurasian circulation during summer half years and the rainfall in summer and the number of heavy rains in the low reaches of Yangtze River have been investigated by using wavelet analysis and rotated principal component analysis based on the data of the pentad mean 500 hPa height field over the Eastern Hemisphere for the 25 years period 1971-1995. The results indicated that there exists a dominant negative correlation between the intensity of LFO(30-60 d) for Eurasian pattern (EU) from June to October and the number of heavy rains in the low reacher of Yangtze River. Meantime, the contrast function analysis (CFA) is proposed with identifying nonlinear relationships between the two variables. In addition, it is found that the number of heavy rains is enhanced and the floods are caused easily when the intensity of the Western Pacific pattern (WP) enhances during the period of May-August by means of the CFA, but the effect is less significant when WP pattern reduces. The rainfall in summer is reduced signifiantly, only when the intensity of the Southen Asia pattern (SA) is enhanced but the number of heavy rains increased, only when the lintensity of SA is reduced during the period of March-May. Hence, the linear or nonlinear correlation may exist simultaneously between the drought/flood and low frequency flow patterns.
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