空气热储存和垂直平流对干旱均匀裸土地表能量平衡的影响

摘要

Based on the data of“Micrometeorological Observation and Evaporation Experiment in Inner Mongolia”,the air heat storage and vertical advection under the typical homogeneous and bare soil underlying surface conditions in arid region of northwest China were estimated,firstly.And on this basis the influence of the air heat storage and vertical advection terms on the surface energy unclosing in the arid region of temperate zone were analyzed.The results showed that the thermal lifting was stronger because of the large temperature gradient in arid area.Consequently,there was considerable vertical advection even if under the homogeneous underlying surface condi-tions.When the air heat storage and vertical advection terms were introduced to the surface energy balance equation,the compensation for the energy non-closure reached averagely about 1.0 W/m2 and 7.1 W/m2,and the closure improved about 2%and 14%,respec-tively.Meanwhile,the residuals of surface energy imbalance decreased from 26.4 W/m2 to 18.2 W/m2 ,and the surface energy clo-sure increased from 82% to 98%.The surface energy balance in arid region had a significant improvement.%利用“内蒙古微气象观测蒸发试验”的数据，估算了我国西北干旱区典型均匀裸土下垫面条件下的空气热储存和垂直平流输送，并分析了空气热储存项和垂直平流输送项对干旱区地表能量不闭合的影响。研究发现：由于干旱区温度梯度大，热力抬升作用较强，即使在均匀下垫面条件下也存在可观的垂直平流输送。在地表能量平衡方程中引入空气热储存项和垂直平流输送项之后，二者对能量不闭合的平均补偿分别达到1．0 W/m2和7．1 W/m2，闭合度分别提高2％和14％，地表能量不平衡残差平均值由26．4 W/m2减小到18．2 W/m2，地表能量闭合度由82％提升到98％，干旱区地表能量平衡有明显改善。