[Show abstract][Hide abstract] ABSTRACT: Eddy covariance and Bowen ratio measurements were carried out over different surfaces, and used to characterize the daily variation of energy fluxes and energy balance under different weather condition. These will be used to identify the phenomena to be addressed in future modeling works. Results show that (1) The diurnal variation characteristics of the fluxes were different over different surfaces, especially the latent heat flux, (2) The energy imbalance persisted in different surfaces with an average about 20%; the energy balance closure was better in the afternoon than in the morning averagely, possibly suggesting the underestimation of storage terms, which are usually larger in the morning.
[Show abstract][Hide abstract] ABSTRACT: This paper describes an evaluation of the aerodynamic resistance models based on direct measurements over a wheat field and a bare soil surface. According to the performance analysis it is shown that (1) Over bare soil surface, the models of Choudhury-2, Verma-Rosenberg and Mahrt-Ek have relatively high precision, while on the winter wheat field, XieXianqun model, Choudhury-1 model and Brutsaert model performed better. (2) The aerodynamic resistance is inversely proportional to the wind speed until reaching a state of stabilization. (3) The model to estimate the aerodynamic resistance should be chosen according to the surface condition.