云南5月强降水天气与亚洲季风变化的关系

 利用相关分析和EOF方法,研究了云南5月大雨、暴雨日数与亚洲季风这一大尺度气候环流背景变化的关系.研究结果表明,云南5月强降水天气与南亚季风强度指数相关较好,其中同期5月,相关系数为0.493,前期4月,相关系数为0.447,均超过了99%的显著性水平;其次是前期1月,相关系数为0.312,通过了95%的显著性检验.而云南5月强降水天气仅与前期4月南海季风强度指数相关较好,相关系数为0.415,通过了98%的显著性检验,与其他月份相关不显著.同时11a滑动相关系数也清楚地反映了南亚季风对云南5月强降水天气的影响大于南海季风.另外,利用EOF方法,获得了云南5月大雨、暴雨日数3种主要的空间分布型:全省一致型(除昭通市)、西部和东部、南部相反型以及东部和西部、南部相反型.第1类型与亚洲季风强度指数关系较为密切,特别是与南亚季风;第2类型主要与南海季风相关较好,第3类型受亚洲季风强度的影响不大.

The relation between the May very heavy rainfall in Yunnan and the Asia monsoon index

The relation between the number of the May heavy storm days in Yunnan and the Asia monsoon intensity index is studied by correlation analysis and EOF methods.It is indicated by the results that there is a good correlation between the May heavy rainfall and the South Asia monsoon index.The correlation coefficients of the corresponding period,May,and the previous period,April,are 0.493 and 0.447 respectively,and go beyond 99% significance level.The correlation coefficient of the previous period,January,is 0.312,and goes beyond 95% significance level.The good correlation between the May very heavy rainfall and the the South Sea monsoon index is in the previous period,April,when the correlation coefficient is 0.415 and goes beyond 98% significance level,but the correlations of other months are not significant.The 11 yeas' running correlation coefficients also indicate that the effect of the South Asia monsoon on the May heavy rainfall in Yunnan is bigger than that of the South Sea monsoon.Three spatial distributions of the May heavy-storm days in Yunnan are obtained by EOF method.There is a good correlation between the first spatial distribution and the Asia monsoon index,especially the South Asia monsoon.There is also a good correlation between the second spatial distribution and the South Sea monsoon index.The effect of the Asia monsoon on the third spatial distribution is not obvious.