摘要
本文根据北京大学地球物理系和中国科学院沈阳生态研究所,1989年5月在吉林省乾安县防风林带区农田中进行的大气边界层及微气象观测得风、温、湿、气压及热量平衡等资料,利用近地面层相似理论的通量廓线关系和能量平衡方程,导出的波文比方法、空气动力学方法、能量平衡方法以及廓线梯度法,计算了林网内上下层的动量通量、感热通量和潜热通量。结果表明:(1)2—4m处动量通量一般小于0.5kgm^(-1)s^(-2),14—16m处一般小于3.0kgm^(-1)s^(-2),并且波动较大;(2)感热通量有较强的日变化规律,并且2—4m处的值大于14—16m处的值,(3)潜热通量在2—4m处小于1—16m的值,在中午前后2—4m并出现负的值;(4)空气动力学方法、能量平衡方法与波文比方法计算结果比较吻合,而梯度法应用于2—4m处的计算结果偏小,因此,梯度法不适用于防护林树冠下层通量的计算。
In this paper, The Bowen ratio method, the aerodynmic method, the energy balance method and the profile gradient method have been calculated the fluxes of mome-tum. Sensible heat latent heat and balk aerodynamic drag coefficients over the windbreaks area. The result shows that, (1) the fluxof mometum between 2m-4m is smaller than 0.5 Kg m s and between 14m-16m is smaller than 3 Kg m s; (2) the bulk aerodynamic drag coefficient CDis the function of ξ and the CD-ξ of relationship is negative interrelate; (3) the flux of latent heat of 14m-16m is greater than that of 14m-16m and the flux of sensible heat of 14m-16m is greater than that of 2-4m, and the available energy (H +λE) is greater than that of 14-16m; (4) the results of the aerodynamic method is almost as good as the results of the Bowen ratio method, and the profile gradient method gives results only less than the Bowen ratio method.
出处
《北京大学学报（自然科学版）》
CAS
CSCD
北大核心
1991年第1期79-88,共10页
Acta Scientiarum Naturalium Universitatis Pekinensis
基金
国家自然基金
关键词
防护林
动量通量
感热通量
Windbreaks
Fluxes of Momentum
Sensible heat
Latent heat
