夏季东北亚低压的年际变化特征及机理

There exists a low pressure system in climatology of low-tropospheric circulation over Northeast Asia, which includes areas of Northeast China, Mongolia, the Russian Far East, and North Japan and northern part of Korean Peninsula. The Northeast Asian low (NEAL) is located in the north edge of East Asian summer monsoon, and it is the most direct circulation through which mid-latitude disturbances in Eurasian continent affects East Asian summer monsoon in the lower troposphere. Many previous studies have addressed important role of synoptic low (cut-off lows or Northeast China cold vortex) in NEA on East Asian summer weather and climate, while understanding on the NEAL is little. This project will investigate characteristics of interannual variability of the summer NEAL, its association with components of East Asian summer monsoon system including Northeast cold vortex, and its impact on East/Northeast Asia. Moreover, the mechanisms, with the focus on how mid-latitude disturbances through the NEAL affects East/Northeast Asia climate, are further explored. Performance of this project will benefit our understanding on circulation variability in Northeast Asia and physical processes of mid-latitude impact on East Asian climate, and improve our knowledge on East Asian summer monsoon system.

气候态上, 夏季东北亚地区（包括中国东北、俄罗斯远东地区、蒙古、朝鲜半岛和日本的北部地区）对流层低层存在一个低压环流。从地理位置来看，该低压（东北亚低压）位于东亚夏季风的北部，是欧亚大陆中高纬度扰动通过对流层低层影响东亚夏季气候最直接的环流系统。以前的研究大多强调了东北亚地区天气尺度的低压（切断低压或东北冷涡）对于东亚天气气候的影响，但对于夏季平均的东北亚低压变化所知甚少。本项目将研究夏季东北亚低压年际变化特征、与东亚夏季风系统成员（包括东北冷涡）之间的关联以及对于东亚、东北亚地区气候的影响；在此基础上，进一步探讨其变化的物理机理，揭示中纬度扰动如何通过调整夏季东北亚低压进而影响东亚、东北亚气候。该项目的实施对于了解东北亚地区环流变化，揭示中纬度扰动影响东亚气候的物理过程，完善对东亚夏季风系统的认识均具有十分重要的科学意义。