| Research Abstract |
This study investigates the scale-dependence, both in time and space (or frequency), of the evapotranspiration, sensible heat flux, and CO_2 uptake at the forest-atmosphere interface. In FY 2007, the last year of the project, the data obtained during an intensive observation made at Fujiyoshita experiment station of the Forestry and Forest Products Research Institute were analyzed, and the surface renewal method was applied to the data. The method formalizes surface flux using a conceptual model of heat and mass exchange between the forest canopy and the atmosphere adjacent to it. During this FY, models of the vertical length scale as a function of the stability used in the surface renewal formalization was investigated.
Moreover, in order to compare with the result above the forest canopy, the scale-dependence was investigated with the data obtained over various land covers. Analyses of the data obtained over a grassland and larch forest in Mongolia revealed that the surface energy bal
… More
ance and the CO_2 uptake at the grassland is influenced more strongly by the amount of precipitation and the soil moisture after the rainfall than those at the forest (Li, et. Al., 2007). Analyses of turbulence data obtained at a grassland over Tibetan plateau indicates that the convective activities at the scale of the boundary layer depth affect the temperature and humidity fluctuations and deteriorate the similarity between them (equality of the eddy diffusivities, Asanuma, et. Al., 2007). Wavelet transform was applied to the data obtained over a rice paddy field in Japan, and the results show the characteristics of the heat and water vapor exchange between the atmosphere and the land surface at the scale around the gap between the turbulence and mesoscale motions (Saito, et. Al., 2007).
These results were presented at some academic conferences, such as that of Japanese Society of Hydrology and Water Resources and the Society of Agricultural Meteorology of Japan (Iwata, et. Al., 2007a, 200b, Saito, et. Al. 2007a, 2007b, Asanuma, et. Al., 2007a 2007b). Less
|
