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.

对西伯利亚松树林的水和能量周期进行了分析，并将结果与在西伯利亚落叶林林获得的结果进行了比较。在两个森林地点之间的这些周期上，季节性变化存在显着差异。 JARVIS类型电导模型的参数与在落叶松森林中获得的参数相似。 JARVIS类型模型中的参数不仅使用我们的数据集，而且使用全局网格数据集的气候变量之间存在明确的关系。该结果表明，尽管植被类型不同，但在同一气候条件下，生理反应可能是相似的。在0阶山谷中研究了水周期特征。当土壤水分高时，森林地板的蒸散量受风速的空间分布的强烈影响。另一方面，底层蒸散不仅受风速的影响，而且还受到干燥土壤条件下土壤水分控制的蒸发效率的空间分布。在低大气层边界层中，使用飞机检查了潜在和明智的热量的空间和时间分布。结果表明，局部循环对西伯利亚松树林上的潜在热通量强烈影响。这种趋势与上面提到的PBL塔获得的地面观察获得的结果一致。