我国东北地区冬季降水和东亚冬季风的关系研究

利用1961-2011年我国东北地区(包括黑龙江、吉林、辽宁、内蒙古东部)的冬季降水资料，分析了东北地区冬季降水量的时空分布和冬季降水日数的时空分布，对比分析了东亚冬季风对我国东北地区冬季降水的影响. 结果表明：东北地区冬季降水量和降水日数分布有明显的区域差异，以内蒙古东南部、辽宁西北部、吉林西部、黑龙江西南部为低值中心，外围辽宁东部，吉林南部，黑龙江东部、中北部、北部，内蒙古东北部等地区为高值区；冬季降水量年际变化呈增加的线性趋势，1980年代中期以后冬季降水量的高值和低值都有明显的增大；年降雪日数年际变化呈线性增加趋势. 1948-2011年东亚冬季风强度指数的结果表明，东亚冬季风呈明显的线性减弱趋势，弱东亚季风主要集中在20世纪80年代中期以后，除内蒙古东南部等少数区域外，我国东北大部分地区的冬季降水量都和东亚冬季风呈负相关. 对应地，东北地区冬季降水量增大，年际变化的幅度变化增大，降水日数增量较小，这可能与东北地区冬季极端降水天气和干旱天气增加有关. 在东亚范围内，我国东北地区冬季降水多年200 hPa U风增强、500 hPa高压减弱、850 hPa东海南风增强，冬季降水少年则相反.

The Relationship Between Winter Precipitation and Eastern Asian Winter Monsoon in Northeast China

The impact of East Asian winter monsoon on winter precipitation in Northeast China is compared and analyzed in this paper. The winter precipitation data of Northeast China (including those in Heilongjiang, Jilin, Liaoning and east of Inner Mongolia) are used to analyze the spatial and temporal distributions of winter precipitation and winter precipitation days during 1961-2011. It is found that the spatial distribution of snowfall and snowfall days in Northeast China have obvious differences, low in southeast of Inner Mongolia, northwest of Liaoning, west of Jinlin and southwest of Heilongjiang, and high in east of Liaoning, south of Jilin, east of Heilongjiang, north of Heilongjiang and northeast of Inner Mongolia. The winter precipitation has a linear increasing trend, and the high and low values of winter precipitation have increased after the mid-1980s obviously. The analysis of East Asian winter monsoon index shows that the linear trend of East Asia winter monsoon has been weak after the mid-1980s; there is a negative correlation between the winter precipitation and East Asian winter monsoon in most regions of Northeast China.