Correlations between Rice Yield in East China and East-Asian Monsoon

LUO Meng-sen1,JIN Yuan-shu2,XIONG Shi-wei2,XIE Zhi-qing3(1.Yancheng Meteorological Bureau,Yancheng 224005,Jiangsu,China;2.Nanjing University of Information Science and Technology,Nanjing 210044,China;3.Jiangsu Meteorological Science Institute,Nanjing 210008,China)

relative meteorology yield;East-Asian monsoon circulation;cross wavelet transform;East China

Based on continuous wavelet transform and bivariate wavelet transform method,the time-frequency variation characteristics of rice yield in east China and East Asia monsoon during 1951～2006 was analyzed;the relationship between relative meteorology yield and East Asia monsoon circulation index was discussed.Results revealed the existence of inter-annual and decadal variation circle of rice yield and East Asia monsoon.Meteorological yield and meridional circulation index of contemporary Asian circulation was mostly positively correlated,especially at 14 a scale.Weak negative correlation was revealed at several time-scale such as quasi-biannual,4 a,6 a and over 18 a.Positive correlation between meteorological yield and latitudinal circulation index during rice growth period appeared at 2～4 a,6～8 a and 10～12 a;while negative correlation appeared at 8～10 a and over 12 a scale,and was the most remarkable at 14 a scale.Variation of East Asian monsoon circulation led to regional climate warming,thereby cause frequent meteorological disasters,and change regional climate resources.It was the main cause for fluctuations in rice production in East China.