摘要
采用1960~2012年5~6月中国东北地区实况降水资料,依据东北冷涡活动客观识别方法,研究东北冷涡活动对东北地区初夏降水的影响,结果表明:5~6月每次东北冷涡过程维持时间以3~7天为主,且具有频发特征,东北冷涡降水累计量占总降水量的62.5%,给出冷涡降水月强度指数,与同期月降水量年际变化具有很好一致性;东北地区初夏降水与东北冷涡降水EOF分解主要模态十分相近,前两个模态分别为全区一致和东北、西南降水相反分布,各占方差贡献的46.8%与42.7%。冷涡降水具有显著"累积效应",该累计效应可总体反映初夏东北地区降水异常分布特征,进一步揭示东北冷涡活动的气候学特征。
Using precipitation observations in Northeast China（NEC） in May and June from 1960 to 2012, an objective identification method for cold vortex activity in NEC is applied to analyze the cold vortex activity in NEC and its impact on cold vortex precipitation in early summer. Results show that periodicity of the cold vortex activity from May to June is 3–7 days with the character of frequent occurrence, and the precipitation induced by the cold vortex accounts for 62.5% of the total rainfall in NEC. A cold vortex monthly rainfall intensity index is defined, which is consistent with the interannual variability of monthly rainfall in the same period. Early summer precipitation pattern in NEC is similar to the leading mode of EOF decomposition of cold vortex precipitation. The first two leading modes of EOF decomposition present a pattern similar over the entire NEC and a pattern that is contrary in the northeast and southwest of the NEC, respectively. The two leading modes account for 46.8% and 42.7% of the total variance, respectively. The concept of ＂Cumulative Effect＂ of cold vortex precipitation（CECEP） is proposed. The CECEP can reflect the characteristics of spatial distribution of summer precipitation anomaly in NEC in general, and further reveal the climatological characteristics of the cold vortex activity.
出处
《大气科学》
CSCD
北大核心
2017年第1期202-212,共11页
Chinese Journal of Atmospheric Sciences
基金
国家自然科学基金项目41405094、41375078、41630424、41275096
吉林省科技发展计划项目20150204023SF~~
关键词
东北冷涡
降水指数
东北地区
初夏降水
EOF
Cold vortex in Northeast China
Precipitation index
NEC（Northeastern China）
Early summer precipitation
EOF
