【摘要】 利用燕山南麓1951-2005年夏季降水资料和NCEP/NCAR高度场、风场资料,采用趋势分析、小波变换、突变检验等方法,对燕山南麓夏季降水规律和东亚夏季风变化进行了分析。结果发现:(1)燕山南麓夏季降水从1980年以来呈减少趋势,在1996年发生了突变,近年减少更加显著。线性减少趋势显著,平均每10 a减少29mm。(2)燕山南麓夏季降水存在10 a的变化周期,东亚夏季风存在11 a的变化周期,二者变化周期基本一致。降水的10 a周期显著,东亚夏季风11 a周期不太显著。(3)强夏季风年,蒙古地区低气压显著降低,蒙古上空低槽活动频繁,极涡明显变弱,燕山南麓夏季降水偏多。弱夏季风年,蒙古地区低气压明显减弱,蒙古上空低槽活动较少,极涡显著加深,燕山南麓夏季降水偏少。(4)燕山南麓夏季降水减少是对东亚夏季风减弱和对应的中高度大气纬环流变化的响应。更多还原

【Abstract】 Based on summer precipitation data in the South Piedmont Regions of Yanshan Mountains for the period from 1951 to 2005 and geopotential height,wind data from NCEP/NCAR for the period 1951 to 2005,the change of summer rainfall in the South Piedmont Regions of Yanshan Mountains and East Asian Summer Monsoon change was analyzed,by using trend analysis,wavelet transform and abrupt change analysis.The results showed that the summer rainfall showed decreasing tendency since 1980,abrupt climate change taking place in 1996.The summer rainfall had obviously linear decreasing tendency,decreasing 29 mm per decade during the past 55 years.The variation of summer rainfall presented a 10-year periods,while the East Asian Summer Monsoon change had a 11-year period.The variation periods of summer rainfall were consistent with that of the East Asian Summer Monsoon.The summer rainfall became less than mean value in the South Piedmont Regions of Yanshan Mountains which was response to the East Asian Summer Monsoon change.更多还原