【作者】 陈金雷； 文军； 王欣； 贾东于； 周娟； 王作亮；

【Author】 CHEN Jin-lei;WEN Jun;WANG Xin;JIA Dong-yu;ZHOU Juan;WANG Zuo-liang;Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions,Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences;University of Chinese Academy of Sciences;

【机构】 中国科学院寒区旱区环境与工程研究所陆面过程与气候变化重点实验室； 中国科学院大学；

【摘要】 湿地是由陆地和水体形成的自然综合体,具有重要的生态、水文和生物地球化学功能,黄河源高寒湿地作为黄河重要的水源涵养区,对其下垫面水热交换特征及关键影响参数的研究具有非常重要的意义。本文利用中国科学院寒旱所麻多黄河源气候与环境变化观测站2014年6-8月观测资料,分析了黄河源区高寒湿地-大气间暖季水热交换特征,并用公用陆面模式(Community Land Model,CLM)模拟了热通量变化,提出针对高寒湿地的粗糙度优化方案。主要结果如下:(1)暖季向上、向下短波与净辐射的平均日变化规律一致,向上、向下长波平均日变化平缓,地表温度升高相对于向下短波具有滞后性,潜热通量始终为正值并大于感热通量;(2)"温度活跃层"为20cm以上浅层土壤,存在明显的日循环规律,土壤中热量9:00下传至5cm深度,温度升高,11:00至10cm深度,13:00至20cm深度,18:00后开始上传,温度降低,40cm及以下深度受此影响较小,热量在土壤中整体由浅层向深层输送;(3)土壤体积含水量平均日变化小,5cm深度为土壤湿度最小层,10cm深度为最大层;(4)麻多高寒湿地动力学粗糙度0mZ在暖季变化稳定,可作为常数,00.0143mZ?m;(5)提出更加适合高寒湿地下垫面暖季附加阻尼1k B?参数化方案,使得热通量模拟效果较CLM原始方案有所提高。以上结果对于研究湿地下垫面陆面过程具有重要意义。更多还原

【Abstract】 Wetland is a natural complex of land and water, which has important functions in ecology, hydrology and biogeochemistry. The alpine wetland in the source region of the Yellow River（SRYR） is the significant water conservation area of the Yellow River, and it is vital to investigate the characteristics of water and heat exchange and its crucial influencing factors. In this paper, the characteristics of water and heat exchange over alpine wetland during the warm season are analyzed by using the field observation data of the Maduo Climate and Environment Monitoring Labotory during June-August 2014 in the SRYR, the heat flux are simulated by meansof CLM（Community Land Model）, and a roughness length scheme, which aims at alpine wetland,is designed based on the simulating results. The main results are as follows:（1） The upward and downward short-wave radition and net radition fluxes in warm season have similar diurnal variation pattern, and diurnal fluctuation of the upward and downward long-wave radiation fluxes aresmall. The increasing of surface temperature lags behind of the downward shortwave radition and the latent fluxes, which is positive, and greater than the sensible flux.（2） "The active layer of soil temperature" is the superficial zone above 20 cm depth, where there has obvious diurnal cycle.The soil temperature starts to increase when the heat is transferred down to 5cm depth at 9:00, and the heat reached 10 cm depth at 11:00, 20 cm depth at 13:00. Soil temperature starts to decrease because of the passing up of heat after 18:00. Soil layer is hardly influenced by radition fluxes under 40 cm, and the overall characteristics of heat transmission is from the superficial layer to deep layer.（3） The diurnal variation of soil volume water content is small, and the 5cm and 10 cm depth have the minimum and maximum, respectively.（4） The roughness length for momentum(Z_0m) over alpine wetland in Maduo during warm season is stable, which can be set as a constant,Z_0m=0.0143m.（5） The new added damping kB^-1 schemes are devised for local alpine wetland, which have better simulating effect over heat flux than the original scheme of CLM. All these results have significant contribution to the research of land surface process over the wetland.更多还原