图7 3种模态时间系数对全球表面平均温度的超前滞后相关系数 a,b图中虚线为通过99%信度检验,c图中虚线为通过90%信度检验, X轴单位:月 Fig.7 The leading or lagged correlation coefficient between time series of three modes and the global average surface temperature Dotted line denote the 99% confidence levels in figure a and b, dotted line denote the 90% confidence levels in figure c,unit of X axis is month |