东北地区夏季风强度的年代际变化分析

Inter-decadal Variation Analysis on the Intensity of Summer Monsoon in Northeast China

利用1961-2004年的NCEP/NCAR逐日再分析资料及全国降水实况资料,客观定义了东北地区夏季风强度指数。在年代际时间尺度上分别进行海平面气压（SLP）、850 hPa流场、500 hPa位势高度、海表温度、北极海冰以及各种振荡指数与东北地区夏季风强度指数的相关分析。结果表明,前冬季和夏季海平面气压、500 hPa位势高度与东北地区夏季风强度指数的正负相关大值区的分布基本一致,但夏季相关性更明显;海表温度与东北地区夏季风强度指数的相关不明显;北极海冰密集度与东北地区夏季风强度指数的相关性较好,前冬季以负相关为主,夏季以正相关为主;各振荡指数中只有NPO指数与东北地区夏季风强度指数有很好的相关性。

The intensity index of East Asian summer monsoon in Northeast China was defined objectively by using NCEP/NCAR daily reanalysis data and national precipitation data form 1961 to 2004.In the inter-decadal time scales,the correlations between sea-level pressure field,850 hPa flow field,500 hPa geopotential height,sea surface temperature,Arctic sea ice concentration,a variety of oscillation index and intensity index of East Asian summer monsoon in Northeast China were studied.The analysis showed that the great value area of correlations is consistent between sea-level pressure field,500 hPa geopotential height field and intensity index of East Asian summer monsoon in Northeast China in pre-winter or summer,and the correlation is more better in summer than in pre-winter.The correlation is poor between the sea surface temperature and intensity index of East Asian summer monsoon in Northeast China,but the correlation is good between the Arctic sea ice concentration and intensity index of East Asian summer monsoon in Northeast China.The correlation is better between the NPO index and intensity index of East Asian summer monsoon in Northeast China than other indexes.