Influence of Radiation on Evaporation Rates: A Numerical Analysis
Influence of Radiation on Evaporation Rates: A Numerical Analysis
复制标题
辐射对蒸发率的影响：数值分析
作者：
K. Heck;E. Coltman;J. Schneider;R. Helmig
我们提出了一个完全耦合的土壤-大气模型，其中包括辐射在两个域之间耦合条件的能量平衡中。该模型能够描述湍流、表面粗糙度和土壤非均质性影响下的蒸发过程，并特别关注辐射对土壤-大气界面质量和能量输运的影响。结果表明，蒸发速率明显受太阳辐照度日循环的支配。在第一阶段蒸发期间，由于蒸发冷却，最高温度受到调节，但在过渡到第二阶段蒸发后，温度急剧上升。我们比较了两种不同的土壤类型，一种是较粗的沙质土壤，另一种是较细的粉质土壤，并分析了三种不同风况下的蒸发速率、地表温度和净辐射。分析了表面波动对辐射和蒸发的影响，表明在多孔介质的丘陵和山谷中，辐射会导致不同的局部干燥模式，这取决于波动的高度和太阳的方向。最后将蒸渗仪的测量数据与数值算例进行了比较，结果表明模型中辐射的测量值与计算值吻合较好，但蒸发速率仍然过高。分析了测量数据与模型数据不一致的可能原因，发现是靠近界面的参数的不确定性，这些参数对确定蒸发速率起决定性作用。
We present a fully coupled soil‐atmosphere model that includes radiation in the energy balance of the coupling conditions between the two domains. The model is able to describe evaporation processes under the influence of turbulence, surface roughness, and soil heterogeneities and focuses specifically on the influence of radiation on the mass and energy transport across the soil‐atmosphere interface. It is shown that evaporation rates are clearly dominated by the diurnal cycle of solar irradiance. During Stage‐I evaporation maximum temperatures are regulated due to evaporative cooling, but after a transition into Stage‐II evaporation, temperatures rise tremendously. We compare two different soil types, a coarser, sandy soil and a finer, silty soil, and analyze evaporation rates, surface temperatures, and net radiation for three different wind conditions. The influence of surface undulations on radiation and evaporation is analyzed and shows that radiation can lead to different local drying patterns in the hills and the valleys of the porous medium, depending on the height of the undulations and on the direction of the Sun. At last a comparison of lysimeter measurement data to the numerical examples shows a good match for measured and calculated radiation values but evaporation rates are still overestimated in the model. Possible reasons for the discrepancy between measurement and model data are analyzed and are found to be uncertainties about the parameters close to the interface, which are decisive for determining evaporation rates.
影响因子：
5.4
作者：
J. Vanderborght;T. Fetzer;K. Mosthaf;K. Smits;R. Helmig
通讯作者：
J. Vanderborght;T. Fetzer;K. Mosthaf;K. Smits;R. Helmig
REV 尺度多孔介质蒸发过程的建模和分析
影响因子：
5.4
作者：
Mosthaf;Helmig
通讯作者：
Helmig