六盘山地区大气水汽的时空差异与驱动因子分析  

Research on temporal and spatial differences of atmospheric water vapor and its driving factors over Liupan Mountain area

作　　者：邓佩云 常倬林 何佳[1,2,3] 杨萌 陈得圆 林彤 穆建华 戴言博 DENG Peiyun;CHANG Zhuolin;HE Jia;YANG Meng;CHEN Deyuan;LIN Tong;MU Jianhua;DAI Yanbo(Liupanshan Atmospheric Science Field Observation and Research Station in Ningxia Hui Autonomous Region,Yinchuan 750002,China;Key Laboratory of Monitoring,Warning and Risk Management of Characteristic Agrometeorological Disasters in Arid Regions,China Meteorological Administration,Yinchuan 750002,China;Ningxia Key Laboratory of Meteorological Disaster Prevention and Mitigation,Yinchuan 750002,China;Yibin Meteorological Bureau of Sichuan Province,Yibin 644000,Sichuan,China;Lanzhou Central Meteorological Observatory,Lanzhou 730020,China)

机构地区：[1]六盘山大气科学宁夏回族自治区野外科学观测研究站,宁夏银川750002 [2]中国气象局旱区特色农业气象灾害监测预警与风险管理重点实验室,宁夏银川750002 [3]宁夏气象防灾减灾重点实验室,宁夏银川750002 [4]四川省宜宾市气象局,四川宜宾644000 [5]兰州中心气象台,甘肃兰州730020

出　　处：《干旱气象》2024年第3期376-384,共9页Journal of Arid Meteorology

基　　金：国家自然科学基金区域创新发展联合基金项目(U22A20577);宁夏回族自治区重点研发计划项目重点项目(2022BEG02010);宁夏回族自治区科技创新团队“宁夏智能数字预报技术研究与应用”项目(2024CXTD006);中国气象局旱区特色农业气象灾害监测预警与风险管理重点实验室开放研究项目(CAMF-202306、CAMF-201814);中国气象局创新发展专项(CXFZ2022J035)共同资助。

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。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 Medium-Range 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.

关 键 词：六盘山 大气可降水量 水汽条件 地形抬升 影响因子 

分 类 号：P481[天文地球—大气科学及气象学]