陆面过程中冠层四流辐射传输模式的模拟性能检验

Validation of the radiative transfer parameterization scheme in land surface process model

中文关键词:  四流辐射，传输模式，检验，模拟，陆面过程，冠层

英文关键词:Four-stream radiative,Transfer odel, Evaluate, Simulation, Land surface process, Canopy

中文摘要:

      利用实际观测资料检验新发展的植被冠层四流辐射传输模式的模拟性能。将浙江大学田间观测数据用于模式试验，其结果表明：在可见光波段，因叶片散射率值较小，四流模式和二流模式模拟结果差别不大，模拟的冠层反照率都接近观测值。这表明在可见光波段，二流模式已经能够较好模拟冠层反照率，四流模式能够提高的精度范围有限；在近红外波段，因叶片散射率值较大，两个模式模拟结果差别较明显，四流模式模拟的冠层反照率相对二流模式的模拟结果更接近观测值。利用第2次雪模式比较计划SNOWMIP资料和改进的10层陆面模式BATS进行耦合试验，将四流模式以及二流模式均耦合到该陆面模式中，其目的是为考察四流模式对陆面模式模拟地表反射太阳短波辐射通量的影响。耦合后得到的结果与SNOWMIP中加拿大BERMS草地站和森林站的观测资料进行了对比。对比结果表明，采用四流模式、二流模式、BATS原辐射传输模式后，耦合四流模式的陆面模式模拟地表反射太阳短波辐射通量最接近观测值。说明采用四流模式能够改善陆面模式对地表反射太阳短波辐射通量的模拟。

英文摘要:

      The experiments were carried out to evaluate the simulations of the four-stream radiative transfer scheme within the vegetation canopy. The numerical results by use of vegetation canopy field observation of Chinese Zhejiang university and two models indicate that the simulations modeled by the two-stream and the four-stream models are mostly consistent in the visible band with small leaf scaterring. The simulations of two models are close to canopy albedo observation in this band. This indicates that the two-stream model can simulate the canopy albedo very well and the improvement of four-stream model is limited. The results also show that the albedo of the canopy modeled by the four-stream model is greatly improved than that of the two-stream model in the NIR band. To evaluate the simulations of the four-stream model for solar radiative flux reflected by land surface in land surface model, the four-stream model and the two-stream model were coupled into land surface process model. Two numerical experiments were carried out by use of BERMS open site and BERMS forest site observation in Canada from the Second Snow Model Intercomparison Project. The results indicate that the simulated solar radiative flux reflected by land surface for four-stream model is closest to observation beyond three radiative schemes coupled into land surface process model. The results proved the four-stream radiative transfer scheme can gain access to accurate canopy albedo. The tests indicate that the simulation of the land surface process model coupled four-stream model is the best among other radiative transfer models.