近50年西北地区春季降水异常与Key海区海温异常的相关及SVD分析

Correlation and SVD Analysis of Spring Precipitation Anomaly in Northwest China and Sea Surface Temperature Anomaly in the Key Region in Recent 50 Years

[目的]分析近50年西北地区春季降水异常与Key海区海温异常的关系。[方法]利用近50年西北地区月平均降水资料和全球逐月海温格点资料,采用相关分析和SVD分析方法,探讨了赤道中东太平洋的海温异常对我国西北地区春季降水的影响。[结果]对于西北地区春季降水,选取前一年8~9月为海温关键时段,赤道中东太平洋海区为海温关键区,简称Key海区(125°~85°W,5°S^10°N);相关分析表明,近50年西北地区春季降水与赤道中东太平洋海区,尤其是Key海区海温(前一年8~9月平均)有较好的正相关关系;SVD分析表明,西北地区春季降水异常具有同位相分布的特征,前一年8~9月赤道中东太平洋海温有较大的正相关系数,尤其在Key海区区有显著的耦合正相关。[结论]该研究为我国西北地区春季旱涝的气候预测提供了理论依据。

[Objective] The aim was to study the relationship between spring precipitation anomaly in Northwest China and sea surface temperature anomaly（SSTA） in the Key region in recent 50 years.[Method] Based on monthly average precipitation in Northwest China and global monthly sea surface temperature（SST） grid data,the effects of SSTA in middle-east equator pacific Ocean on spring precipitation anomaly in Northwest China were discussed by means of correlation and SVD analysis.[Result] For spring precipitation in Northwest China,the key period of SST was from August to September in former year,and the middle-east equator pacific Ocean（125°-85° W,5° S-10° N） was named ＂Key region＂;correlation analysis showed that there was obvious positive correlation between spring precipitation in Northwest China and SSTA（monthly average from August to September in former year） in middle-east equator pacific Ocean,especially Key region SVD analysis revealed that spring precipitation anomaly in Northwest China distributed in phase,while SST in middle-east equator pacific Ocean from August to September in former year had higher positive correlation coefficient,and there was obvious positive couple correlation in Key region.[Conclusion] The study could provide theoretic foundation for the prediction of drought and flood in Northwest China.