【摘要】 为有效开发六盘山地区空中云水资源，提高人工增雨的科学性，需掌握该区域大气水汽的时空分布特征及其原因。利用1989—2018年六盘山地区国家基本站降水观测资料和同期欧洲中期天气预报中心（European Centre for Medium-Range Weather Forecasts,ECMWF）第五代大气再分析资料（ERA5），分析该区域大气可降水量、比湿、相对湿度、水汽通量等大气水汽要素的时空变化，并从水汽输送、地形作用、浮力频率的影响等方面分析六盘山不同地区水汽条件及降水差异的原因。结果表明：一年中绝大多数时间六盘山山顶及东坡大气水汽条件均优于西坡，大值区主要集中在六盘山系主峰附近，并具有明显的季节变化特征。六盘山东坡，受地形抬升作用引起500 hPa辐散、700 hPa辐合的动力场，在夏季最明显，冬季最弱；浮力频率冬季最高，夏季最低；东坡更高的浮力频率及更陡峭的地形，使重力波效应更为明显，具备更有利的垂直上升扩散条件及更大的降水潜力。更多还原

【Abstract】 In order to effectively develop the cloud water resources in the Liupan Mountain area and improve the scientificity of artificial precipitation enhancement, it is necessary to grasp the spatial and temporal distribution characteristics of atmospheric water vapor in the region and its causes. In this paper, the precipitation observation data of national basic meteorological stations in the Liupan Mountain area from 1989 to 2018 and the Fifth Generation Atmospheric Reanalysis Data(ERA5) of European Centre for MediumRange Weather Forecasts(ECMWF) during the same period are used to analyze the spatial and temporal changes of atmospheric water vapor elements such as precipitable water, specific humidity, relative humidity and water vapor flux in this area. The reasons for the difference of water vapor conditions and precipitation in different areas of the Liupan Mountain area are analyzed from the aspects of water vapor transport, terrain effect and influence of buoyancy frequency. The results show that the water vapor conditions over the top and the east slope of the Liupan Mountain are better than those over the west slope in most of the year. The large value areas are mainly concentrated near the main peak of the Liupan Mountain, and water vapor condition has obvious seasonal variation characteristics. Over the eastern slope of the Liupan Mountain, the dynamic field of 500 hPa divergence and 700 hPa convergence caused by the uplift of the terrain is the most obvious in summer and the weakest in winter. The buoyancy frequency is the highest in winter and the lowest in summer. The higher buoyancy frequency and steeper terrain on the eastern slope make the gravity wave effect more obvious, resulting in more favorable vertical upward diffusion conditions and greater precipitation potential.更多还原