若尔盖高原高寒草甸地表能量交换和蒸散研究  

Surface Energy Exchanges and Evapotranspiration of an Alpine Meadow on the Zoige Plateau

作　　者：郭小璇 王凯[2] 李磊[2] 张寒 马磊 姚志生[2] 张伟[2] 胡正华[1] 郑循华[2,5] GUO Xiao-xuan;WANG Kai;LI Lei;ZHANG Han;MA Lei;YAO Zhi-sheng;ZHANG Wei;HU Zheng-hua;ZHENG Xun-hua(Collaborative Innovation Center of Meteorological Disaster Forecast,Early-Warning and Assessment/School of Applied Meteorology,Nanjing University of Information Science and Technology,Nanjing 210044,China;State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry,Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China;School of Geographic and Environmental Sciences,Tianjin Normal University,Tianjin 300387,China;Institute of Meteorology and Climate Research,Atmospheric Environmental Research(IMK-IFU),Karlsruhe Institute of Technology,82467 Garmisch-Partenkirchen,Germany;College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;Hebei Provincial Meteorological Technical Equipment Center,Shijiazhuang 050021,China)

机构地区：[1]南京信息工程大学气象灾害预报预警与评估协同创新中心/应用气象学院,南京210044 [2]中国科学院大气物理研究所大气边界层物理和大气化学国家重点实验室,北京100029 [3]天津师范大学地理与环境科学学院,天津300387 [4]卡尔斯鲁厄理工大学气象与气候研究所大气环境研究部,德国加尔米施-帕滕基兴82467 [5]中国科学院大学地球与行星科学学院,北京100049 [6]河北省气象技术装备中心,石家庄050021

出　　处：《中国农业气象》2021年第8期642-656,共15页Chinese Journal of Agrometeorology

基　　金：国家重点研发计划项目(2016YFA0602302)。

摘　　要：若尔盖高原高寒草甸生态系统是青藏高原能量和水分循环的重要组成部分,但该地区地面水热通量观测数据非常缺乏。本研究基于涡动相关法,于2013年11月1日-2014年10月31日,利用三维超声风温仪和红外开路二氧化碳/水汽分析仪在若尔盖高原一典型高寒草甸开展周年通量观测,以揭示其地表能量交换和蒸散特征及影响因素。结果表明:高寒草甸地表能量通量各组分呈显著的日变化和季节变化特征,净辐射通量、感热通量、潜热通量和土壤热通量的年均值分别为94.5、21.0、51.8和1.2W×m^(-2)。非生长季感热稍占优势,生长季潜热占绝对主导地位,波文比全年平均值为0.70,能量平衡闭合率年平均值为0.77。辐射是感热通量的主要气象影响因子,潜热通量则受温度、辐射和饱和水汽压差共同影响。日蒸散量变化范围为0.12~5.09mm×d^(-1),全年平均值为1.82mm×d^(-1)。非生长季蒸散主要受土壤表面导度因子控制,生长季则由辐射主导,土壤和植被表面导度因子为次要影响因素。在季节尺度上,蒸散的变化取决于降水分布,全年降水和蒸散量分别为682.7mm和673.6mm,其中生长季分别占全年总量的84%和82%。6-7月降水匮乏抑制了蒸散,此时土壤储水成为蒸散的主要水源,从全年看,降水基本都以蒸散的方式返回大气。与青藏高原上同类观测研究相比,地表能量通量和蒸散都有相似的季节变化趋势,但观测到的年平均波文比和年蒸散量最大,气温、降水、地表植被等因素的共同作用导致这一结果。研究数据可作为地面验证资料,用于若尔盖地区陆面模式参数化方案的优化和卫星遥感反演资料的校验。The alpine meadow ecosystems of the Zoige Plateau play important roles in the energy and water cycle of the Qinghai-Tibet Plateau,but observation data of this region regarding to surface energy and water fluxes are very scarce.In this study,annual flux measurements were conducted based on the eddy covariance technique at a typical alpine meadow on the Zoige Plateau by using a three-dimensional sonic anemometer and an infrared open-path carbon dioxide and water vapor analyzer.The surface energy and evapotranspiration(ET)fluxes were calculated at the basis of half-hour.The purpose of this study is to reveal the characteristics and influencing factors of surface energy exchanges and ET.The results are as follows.All energy flux components showed clear diurnal and seasonal variation patterns.The annual mean net radiation,sensible heat,latent heat,and soil heat fluxes were 94.5,21.0,51.8 and 1.2W×m^(-2),respectively.The energy fluxes showed a“single peak”diurnal variation pattern both in the growing season and the non-growing season,despite different peak times for different energy components.During the non-growing season,the sensible heat fluxes were slight larger than the latent heat fluxes,while the latter absolutely dominated during the growing season.The annual mean Bowen ratio and energy closure rate were 0.70 and 0.77,respectively.Radiation was the most important environmental factor that influenced the sensible heat fluxes,while temperature,radiation and water vapor pressure deficit for the latent heat fluxes.The ET fluxes during the growing season were significantly larger than those during the non-growing season.The daily ET fluxes ranged from 0.12 to 5.09mm×d^(-1),and the annual mean value was 1.82mm×d^(-1).Evapotranspiration during the non-growing season is controlled by the surface conductivity;during the growing season it is dominated by the radiation,rather than the surface conductivity of soil and vegetation.On a seasonal scale,the dynamics of ET depended on the seasonal variation of precipitati

关 键 词：高寒草甸 能量交换 蒸散 涡动相关 若尔盖高原 青藏高原 

分 类 号：S812.1[农业科学—草业科学]