地表通量研究进展

Advance of Research on Surface Flux

通过对国内外地表通量中的显热和潜热通量的研究进展从试验仪器、计算模型和遥感反演三个方面分别进行综述。目前广泛应用于地表通量研究的仪器有波文比、涡度相关仪和闪烁通量仪。计算模型主要有涡度相关法 ,波文比法、空气动力学法 ,能量平衡—空气动力学阻抗法 (即遥感法 )、Penman -Monteith模型、互补相关模型和SR模型等。遥感反演主要立足于地表热量平衡方程 ,通过反演方程中的净辐射、土壤热流量和显热通量 ,进而推算出潜热通量。在最后还对目前地表通量研究中的热点问题进行了分析。

The advance of research on surface sensible heat flux and latent heat flux was analyzed, ranging from experimental instruments to calculating model and to inversion of remote sensing. At present the instruments widely used include Bowen ratio, Eddy correlation techniques and Scintillometer. It is generally thought as constant flux layer over a homogeneous surface, therefore, flux data can be obtained from point measurements using Bowen ratio or eddy correlation techniques. However, over a heterogeneous land surface special techniques are necessary to estimate the area-averaged fluxes. In the case, scintillometers are used most widely and most effectively. Flux calculating models mainly include Eddy correlation, Bowen ratio, Energy balance and aerodynamic resistance model, Penman-Moteinth model, Priestley-Taylar, Dual sources model, and Surface Renewal model. Single-layer, two-layer and multi-layer model of Energy-balance and aerodynamic resistance model are introduced. At the same time Surface Renewal model are described in detail. The images of remote sensing can give us real-time and rich surface information. As the advance of spatial, temporal and spectral resolution, the research on inversing surface flux by using remote sensing has become a hot topic. Now it is mainly based on the surface energy balance equation. Latent heat flux can be derived from inversing net radiance, soil heat and sensible heat flux. Finally, some hot topics in the research of surface flux were analyzed. They include (1) the usage of Bowen ratio on heterogeneous surface and under horizontal convection; (2) the research on greenbelt's ecological effect of cities based on flux; (3) scaling-up.