摘要
利用FSAM（Flux Source Area Model）模型，对中国科学院长武黄土高原农业生态试验站2004-2005年冬小麦生育期内的通量数据空间代表性进行了研究。结果发现，在90％贡献率水平下，整个冬小麦各生育期内通量源区范围动态变化明显，通量贡献最大点在距离观测点7．7—36．2m范围内变化。在盛行风向上，通量源区离观测点最近点为3．3m，最远点可达172．8m；在侧风向上，通量源区在38．1～128．4m范围内变化。不同观测高度的对比研究表明，观测高度从1．86ITI增加到12．17m，盛行风向上源区距观测点最远距离从172．8m增加到1555．2m；在侧风向上则从123．2m增加到665．8m，通量源区范围随高度的增加而增大。大气稳定度对通量贡献源区影响很大，在大气稳定状态下，通量源区面积最大，距观测点最远距离达到135．3ITI；中性条件下次之，为101．7m；在不稳定条件下面积最小，为36．3m。同一日内，夜晚源区面积较白天大。在日和季尺度上，大气稳定度是影响通量源区范围的一个重要因素。
Spatial rcpresentation of flux data during winter wheat growing period from 2004 to 2005 was analyzed in Changwu Station, the Chinese Academy of Sciences by FSAM （Flux Source Area Model）. The results indicated that flux source area （FSA, footprint） was dramatically changed during each growing stage of winter wheat under the effect level of 90% confidence. The source area of the maximum footprint was located between 7.7 m and 36.2 m from the observation point. In the prevailing wind direction, the upwind range of source area was 3.3 - 172.8 m, and vertical upwind range was 38.1 - 128.4 m. The comparison of footprint among different measurement heights showed that： with the measurement height increased up from 1.86 to 12.17 m, the length of footprint expanded from 172.8 m to 1555.2 m in the prevailing wind direction and from 123.2 m to 665.8 m in the vertical direction. The footprint fluctuated with atmospheric stability. The length of the source area is the largest under the stable atmospheric stratification with the distance of 135.3 rn from the observation point, reaching 101.7 m under the condition of moderate atmospheric stratification, and the smallest is under unstable stratification with the distance of 36.3 m. Meanwhile, the source area in night is larger than that in daytime. In daily and seasonal scales, atmospheric stability has an important effect on flux source area.
出处
《地球科学进展》
CAS
CSCD
北大核心
2009年第2期211-218,共8页
Advances in Earth Science
基金
中国科学院知识创新工程重要方向项目“黄土高原旱作农田生产力及水分生态过程调控”(编号:KZCX2-YW-424)
教育部长江学者和创新团队发展计划项目“黄土高原流域生态系统中水土迁移机制及其调控原理”(编号:IRT0749)资助
关键词
涡动相关
通量贡献源区
冬小麦
黄土高原
Eddy covariance
Flux-source area
Winter wheat
The loess plateau.
