近百年高低层大气环流的演变特征及其与中国降水变化的关系

 分析了101 a北半球低层和高层大气环流(包含四大涛动及W,C,E 3种环流型、副高强度)的演变特征,并讨论了大气环流因子的年际和年代际变化与中国降水的关系.结果表明,无论是高层还是低层大气环流特征随时间尺度的不同而不同,最显著的变化是7 a以下的年际变化.低层因子的年际变化比对流层因子明显;对流层因子的气候基本态的变化比低层因子明显.SO是低层因子中发生年际变化的强信号,NPO是低层因子中时间尺度28 a以上变化的强信号.副高是对流层中发生年际变化的强信号,E型环流是对流层中时间尺度28 a以上变化的强信号;中国近百年的降水量变化有显著的小于3.5 a,3.5~7 a,7~14 a的周期变化;中国降水和高、低层大气环流因子之间存在明显的同时相关和滞后相关关系.同时相关中,影响中国降水的主要因子为:W,NPO,SO;滞后相关中,影响中国降水的主要因子为:W,NAO,AO,E.

The Long-time change characteristics of atmospheric circulation at lower and upper level and its correlation with China rainfall in recent 100 years

The multi-timescale variations of China rainfall and atmospheric circulations in recent 100 years,including the key atmospheric oscillations,W,C,E and subtropical high(SH) are studied.The relation-ships of atmospheric circulations and China rainfall on different time scales are also studied.The results are as following.Firstly,the atmospheric circulations in the lower and higher layer show the significant interannual scales,especially,the interannual variation of 7 years.And the interannual variation in lower atmospheric layer is clearer than that in troposphere but it is reverse in the more than 28 years band of period.SO and SH are the strongest signal in the interannual scales.In the more than 28 years band of period,NPO and E are the strongest signal.Secondly,the rainfall variation of China in the late 100 years shows the significant periodicity in less 3.5years,3.5 to 7years and 7 to 14 years.At last,the contemporary and previous relationship between the rainfall and high-low atmospheric layer.In the previous period,the key factors to China rainfall are W,NPO and SO,while W,NAO,AO and E are the key factors in the upper period.