Seasonal variation of the surface boundary layer and the lower atmospheric boundary layer over boreal forests

北方森林表面边界层和低层大气边界层的季节变化

基本信息

批准号：
12460063
负责人：
OHTA Takeshi
金额：
$ 9.22万
依托单位：
Nagoya University (2001-2002)Iwate University (2000)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

项目摘要

Analyses on water and energy cycles at a Siberian pine forest are carried out, and the results are compared with those obtained at a Siberian larch forest. There are significant differences of seasonal variations on these cycles between the two forest sites. The parameters for a Jarvis type conductance model are similar to those obtained at the larch forest. There are clear relationships between the parameters in the Jarvis type model using not only our dataset but published datasets and the climatic variables using global grid datasets. This result suggests that physiological responses might be similar under same climatic conditions in spite of different vegetation types.Water cycles characteristics are investigated in a 0-order valley. Evapotranspiration from forest floors are strongly affected by spatial distributions of wind speed when soil moisture is high. On the other hand, understory evapotranspiration is affected by not only wind speed but also the spatial distribution of evaporation efficiency controlled by soil moisture under dry soil condition.The spatial and temporal distributions of latent and sensible heat fluxes in the lower atmospheric boundary layer are examined using a airplane. The results show that local circulation affects strongly the latent and sensible heat fluxes over the Siberian pine forest. This tendency agrees with the results obtained by the ground observation using a PBL tower mentioned above.

对西伯利亚松林的水和能量循环进行了分析，并将结果与西伯利亚落叶松林的结果进行了比较。两个森林地点之间的这些周期的季节变化存在显着差异。贾维斯型电导模型的参数与在落叶松森林中获得的参数相似。贾维斯类型模型中的参数之间存在明显的关系，该模型不仅使用我们的数据集，还使用已发布的数据集，以及使用全球网格数据集的气候变量。这一结果表明，尽管植被类型不同，但在相同的气候条件下，生理反应可能相似。在0级山谷中研究了水循环特征。当土壤湿度较高时，森林地面的蒸散量受到风速空间分布的强烈影响。另一方面，在干燥土壤条件下，林下蒸散量不仅受到风速的影响，还受到土壤湿度控制的蒸发效率空间分布的影响。研究了低层大气边界层潜热通量和感热通量的时空分布。使用飞机。结果表明，局地环流对西伯利亚松林的潜热通量和感热通量影响很大。这一趋势与上述使用 PBL 塔进行地面观测得到的结果一致。