Time-scale analyses of heat/water vapor/carbon dioxide transport in the lower atmosphere

本文研究了森林-大气界面蒸散量、感热通量和CO2吸收在时间和空间(或频率)上的尺度依赖性。在2007财年，也就是该项目的最后一年，对在林业和林产研究所藤吉吉下试验站进行密集观测所获得的数据进行了分析，并对数据进行了表面更新方法。该方法使用森林树冠和邻近大气之间的热量和质量交换的概念模型来形式化地表通量。在本财年期间，研究了地表更新形式化中使用的垂直长度尺度作为稳定性的函数的模型。此外，为了与林冠上方的结果相比较，利用不同土地覆盖的数据研究了垂直长度尺度的尺度依赖关系。对蒙古草原和落叶松森林上空获得的数据的分析表明，地表能量平衡…草地吸收CO_2受降雨量和降雨后土壤水分的影响比林地更大(Li，et.等人，2007年)。对青藏高原草原湍流资料的分析表明，边界层深度尺度上的对流活动影响了温度和湿度的波动，并恶化了它们之间的相似性(涡旋扩散系数相等，Asanuma等)。等人，2007年)。将小波变换应用于日本稻田上空的资料，结果表明，在湍流和中尺度运动(Saito等)之间的尺度上，大气和地表之间的热量和水汽交换的特征。这些成果已在一些学术会议上发表，例如日本水文水资源学会和日本农业气象学会(岩田等人)。等，2007a，200b，Saito等。艾尔。2007a、2007b、Asanuma等等，2007a，2007b)。较少

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