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中文摘要: 为了更好地了解大气与森林的物质和能量交换,用二层三维超声风速温度仪测量了重庆市郊松林风速和温度脉动值。采样速率为每秒1次和11次,数字量记录。计算了湍流动量通量和热通量的日变化,以及湍流风速的统计量和功率谱。结果表明,冠层上动量通量向下传输,而冠层内大多向上传输;冠层内湍流风速u的三阶矩平均值大于零,w的小于零;冠层上无因次湍流风速分量u、w标准差和无因次湍流动能耗散率与局地Monin-Obukhov长度相关,而在冠层内不存在这种相关性;满足“-2/3"幂次律的u,w功率谱惯性区在冠层上和冠层内都存在。
中文关键词: 湍流，测量，森林，超声风温仪
Abstract:Two three-dimensional sonic thermo-anemometer probes were used to measure velocities and temperatures above and within a pine forest near Chongqing city,Sichuan Province, in order to comprehend mass and energy exchange between atmosphere and forest. The turbulent fluxes of momentum and heat, and statistics and spectra of wind speed fluctuations were calculated from the digital data sampled at rate of both 1s~(-1) and 11s~(-1) , using eddy correlation and FFT method. The results show that above the canopy kinetic momentum was transported downwards, while within the canopy it was transported upwards. Within the canopy mean skewness of u was positive and that of w negative. Above the canopy both the dimensionless standard deviation of u and w and dimensionless turbulence, dissipation rate were functions of local Monin-Obukhov length, while within the canopy those variables did not show the correlations. The "—2/3" power rules, however, were existed at the inertial subrange of power spectra of wind speed either above the canopy or within it.
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基金项目:
| 作者 | 单位 |
| 麻益民 | 中国科学院大气物理所，北京 100029 |
| 郜永祺 | 中国科学院大气物理所，北京 100029 |
| 李德新 | 中国科学院大气物理所，北京 100029 |
| 胡景琳 | 中国科学院大气物理所，北京 100029 |
| Author Name | Affiliation |
引用文本：
麻益民,郜永祺,李德新,胡景琳,1993.松林冠层大气湍流结构观测研究[J].气象,19(12):13-18.
,1993.Observational Study of Atmospheric Turbulence above and within a Pine Forest[J].Meteor Mon,19(12):13-18.
麻益民,郜永祺,李德新,胡景琳,1993.松林冠层大气湍流结构观测研究[J].气象,19(12):13-18.
,1993.Observational Study of Atmospheric Turbulence above and within a Pine Forest[J].Meteor Mon,19(12):13-18.