Energy and water cycles in Siberian biosphere

西伯利亚生物圈的能量和水循环

基本信息

批准号：
11201206
负责人：
OHTA Takeshi
金额：
$ 37.7万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research on Priority Areas (B)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2001
项目状态：
已结题

项目摘要

1. The sum of the turbulent fluxes was generally in good agreement with the available energy flux, except when the latent heat flux was large, when the total turbulent fluxes often exceeded the available energy flux ; this bias in the energy balance was affected by the wind direction. Although the reasons for this phenomenon at this site are not clear, it might be an effect of the larch forest surrounding the site.2. The seasonal variation and magnitude of the latent heat flux (IE) were similar to those of the sensible heat flux (H) ; both were maximal in June, Consequently, the Bowen ratio was around 1.0 on many days during the study period. On some clear days just after rainfall events, IE was very large, and the sum of H and IE exceeded the net all-wave radiation.3. Remarkably, from 7 to 22 July 2000, which corresponded to a long rainless period, IE decreased and was smaller than H. Considering the diurnal change in the saturation deficit and soil moisture for the same period, it is thought that IE was affected by the atmosphere rather than by the soil.4. The contribution of understory evapotranspiration (Eu) to the evapotranspiration from the entire ecosystem (Et) was 25-50% of Et throughout the period analyzed, and a similar relationship was obtained for overstory transpiration (Eo). These results suggest that Eu plays a very important role in the water cycle at this site.5. Significant differences in the water and energy exchanges of the pine and larch forests at Spasskaya Pad occurred just after the snowmelt season. This could have been due to the difference in species (evergreen versus deciduous forest) or in soil thawing conditions. Consequently, the shape of the seasonal variation in the Bowen ratio over the course of the study period at the pine site was markedly different from that in the larch forest.

1。湍流的总和通常与可用的能量通量非常吻合，除非潜热通量大，否则总湍流通常超过了可用的能量通量；能量平衡中的这种偏见受风向的影响。尽管在此地点造成这种现象的原因尚不清楚，但这可能是该地点周围落叶林的影响。2。潜热通量（IE）的季节变化和大小与明智的热通量（H）相似。两者在6月最大，因此，在研究期间的许多天，鲍恩的比率约为1.0。在降雨事件发生后的某些明显的日子里，IE非常大，H和IE的总和超过了全波辐射。3。值得注意的是，从2000年7月7日到22日，与长雨期相对应，IE减少，比H小。考虑到同一时期饱和赤字和土壤水分的昼夜变化，人们认为IE受大气而不是土壤的影响。4。在分析的整个期间，植树蒸散液（EU）对整个生态系统（ET）的蒸散量的贡献是ET的25-50％，并且获得了类似的关系，以实现过渡性（EO）。这些结果表明，欧盟在此地点的水周期中起着非常重要的作用。5。在融雪季节之后，Spasskaya垫的松树和落叶林的水和能量交换的显着差异。这可能是由于物种（常绿与落叶林）或土壤融化条件的差异所致。因此，在松树部位的研究期间，鲍恩比率的季节性变化与在落叶林森林中的形状明显不同。