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地表能量不平衡是陆面过程研究中普遍遇到的问题。利用黄土高原陆面过程试验的观测资料,研究了半干旱区热量在土壤中的缓慢传递过程(简称“慢过程”)对地表能量平衡的影响。结果如下:(1)热量在土壤浅层线性传递,30 min内传递厚度约为1.5 cm;(2)基于慢过程,提出了计算土壤热储、土壤热通量和地表土壤热通量的传输线、四边形和三角形等3套方法,并给出了其公式;(3)3套方法得到的地表能量闭合度在上半天高于或接近不考虑慢过程的常规法,下半天与整个白天低于或接近常规法;(4)常规法在一定程度上存在上半天低估、下半天高估、整个白天也高估土壤热通量、土壤热储、地表土壤热通量及闭合度的缺点。所以,在半干旱区,考虑慢过程并选用合适的方法不仅可提高或维持闭合度水平,还可克服常规法的缺点。
Surface energy imbalance is a common problem encountered in the study of land surface processes. Based on the observation data of the land surface process in the Loess Plateau, the influence of the slow transfer of heat in the soil (referred to as “slow process”) on the energy balance of the earth’s surface was studied. The results are as follows: (1) The transmission of heat in the shallow soil layer is linear in 30 min, and the transmission thickness is about 1.5 cm in 30 min. (2) Based on the slow process, the transmission line for calculating soil heat storage, soil heat flux and surface soil heat flux , Quadrangles and triangles, and its formulas are given. (3) The closure of the surface energy obtained by the three sets of methods is higher than or close to the conventional method without considering the slow process in the first half of the year, lower than (4) conventional method to some extent, there is the first half of underestimated the next half-day overestimated the entire daytime overestimation of soil heat flux, soil thermal storage, surface soil heat flux and closure defects. Therefore, in the semi-arid area, considering the slow process and choosing the appropriate method can not only improve or maintain the level of closure, but also overcome the shortcomings of the conventional method.