夏季河西地区绿洲-沙漠环境相互作用热力过程的初步分析

从绿洲和沙漠地面能量平衡方程和水分平衡方程出发，得到了表达绿洲稳定度和绿洲环流的表达式，绿洲地表温度低于沙漠的最主要原因是绿洲地表明显的蒸发。绿洲上大气稳定度的增加对于维持绿洲是一个重要的自我保护机制。从动力学角度来看，绿洲区明显的下沉(上升)运动将使大气稳定(不稳定)。反照率效应将减弱绿洲风环流，相反，蒸发效应会驱动它。绿洲中过多的蒸发使绿洲地表温度低于周围沙漠。这种温度差异使绿洲风环流产生，并且使绿洲区产生下沉运动、沙漠区产生上升运动。

Preliminary Study of Thermodynamic of Oasis-Desert Interaction in Hexi Area in Summer

Based on the surface heat and water balance facts in desert and oasis, the equations of atmospheric stability and circulation over the oasis are given. It shows that the main causes that makes oasis surface temperature lower is the obvious great evaporation from the oasis surface. The atmospheric stability over the oasis is an important self-protection mechanism to maintain oasis. From dynamic point of view, obvious downdraft (updraft) over the oasis leads to stabilization (destabilization) of the atmosphere. The albedo effect will reduce the oasis circulation, on the contrary, the evaporation from the oasis can drive the oasis circulation. The excessive evaporation from oasis (than from the desert surface) makes the oasis surface is colder than the surrounding desert surface. The temperature difference between oasis and surrounding desert drives an oasis breeze circulation, in which there is the downdraft over the oasis and the updraft over the desert.