青藏高原大气边界层过程再认识观测实验研究

The dynamic and thermal interactions for Tibetan Plateau’s and the global atmospheric circulations are dominated by atmospheric turbulence and through the ground-air coupling process in atmospheric boundary layer. The ground-air coupling process and turbulent flow filed in Tibetan Plateau are inevitably different with that in plain area due to the special surface and terrain. In Nagqu Station of Plateau Climate and Environment (NaPlaCE), the project “Observing and studying again the atmospheric boundary layer process in Tibetan Plateau” will conduct an experiment by applying the surface meteorological observation system, wind profiler, GPS sonde and tethered balloon sounding system and describe the full vertical structures, from surface to the lower stratosphere, of wind, temperature, humidity, turbulent intensity and so on. Based on the experimental results and a new perspective, we will apply the theory of mountain peak heating effect and atmospheric turbulence theory of nonequilibrium thermodynamics to reveal the characteristics of turbulence, boundary layer and land surface processes in Tibetan Plateau; and to study the relation between cold or hot source and land surface processes in Tibetan Plateau; and to explore the dynamic effect of the Tibetan Plateau terrain, corresponding ground-air interactions and the influencing mechanism of ground-air coupling process on the global energy and water cycle.

青藏高原与全球大气环流的动力和热力相互作用都是由大气边界层和大气湍流过程所主导，通过地—气耦合过程实现的。青藏高原特殊下垫面必然给大气边界层过程和大气湍流以及地—气耦合造成与平原地区不同的特征。该项目拟以中国科学院青藏高原那曲高寒气候环境观测站为基地，利用近地面层微气象观测系统结合风廓线仪、GPS和系留探空系统开展“青藏高原大气边界层过程再认识观测实验研究”。构建从地表至平流层下部较完整的风速、温度和湿度及湍流强度廓线日变化垂直结构。从一个新视角，以“山峰加热效应”原理和大气湍流非平衡态热力学理论研究青藏高原大气边界层、大气湍流和陆面过程及其与高原冷热源的关系；探索青藏高原地形的动力效应与地-气相互作用，青藏高原地-气耦合过程影响全球能量和水分循环的机制。

青藏高原与全球大气环流的动力和热力相互作用都是由大气边界层和大气湍流过程所主导，通过地—气耦合过程实现的。青藏高原特殊下垫面给大气边界层过程和大气湍流以及地—气耦合造成与平原地区不同的特征。项目利用近地面层微气象观测系统结合风廓线仪、GPS和系留探空系统开展“青藏高原大气边界层过程再认识观测实验研究”。结果分析了从地表到平流层下部较完整的风速、温度和湿度廓线日变化垂直结构；研究青藏高原大气边界层、大气湍流和陆面过程及其与高原冷热源的关系；确定了一个普适的边界层高度诊断方程；通过研究湍流结构，揭示了近地面层不满足常通量层条件的物理原因，也提出了大气边界层湍流研究新的入手点。这些成果提高了我们对大气湍流的认识，为大气湍流理论的进一步完善提供了实验基础，也为今后的实验和理论研究提出了明确的方向。