Abstract: Using the micrometeorological data obtained over the moving sand dune in Keerqin sand area in Inner Mongolia in summer of 2001 and spring of 2002, the surface temperature was determined and the characteristics were analyzed over the sand dune area. The idea is using discrete Fourier transform on the temperatures of different layers and applying soil heat conduction equation. The results are that soil temperature conductivity ratios which are calculated from the decline of the soil temperature amplitude and phase difference agree well under the assumption of layered homogeneity. The surface temperature was calculated using the relationship of the soil temperature conductivity ratios at different depths and the amplitude and phase of dominant and harmonic frequencies of soil temperature. The surface temperatures calculated from observed soil temperatures at 5 cm and 10 cm depth show a good agreement. The amplitude of soil temperature waves decreases exponentially with depth. The diurnal variation of soil temperature at 80 cm is small.

Key words: surface temperature, soil temperature, soil temperature conductivity ratio, layered homogeneity, discrete Fourier transform

摘要： 利用2001年夏季和2002年春季在内蒙古科尔沁沙地开展的近地面层微气象观测资料, 计算和分析了流动沙丘下垫面地表温度及特征规律。在不同土壤深度间土壤性质分层均匀的假设下, 对不同实测土壤温度进行离散傅立叶变换, 结合土壤热传导方程, 由土壤温度主频振动振幅衰减与位相差计算的土壤导温率具有较好的相关; 利用不同深度土壤导温率关系和土壤温度主频及各谐波振动的振幅与位相推算地表温度, 由5 cm和10 cm土壤温度测量值计算的地表温度相关性较好。土壤温度振动日振幅随深度按指数衰减, 80 cm深度处地温值的日变化较小。

关键词: 地表温度, 土壤温度, 土壤导温率, 分层均匀, 离散傅立叶变换