高原湖泊湖-气交换特征及其对边界层结构的影响

In the study of atmospheric science, especially the atmospheric boundary layer, structure of the atmospheric boundary layer and turbulent transport characteristics of inhomogeneous surfaces over complex terrain are hot and difficult points. This project is based on observations of the Erhai Lake. Long-term lake-atmosphere and land-atmosphere observation datum are analyzed to investigate turbulence exchange and atmospheric boundary layer structure of different underlying surfaces. Lake effects on horizontal and vertical structure of local circulation are simulated by lake-atmosphere coupled model. Parameterization of energy and vapor exchanges are improved. The calibrated lake-atmosphere coupled model is applied to investigate influence of weather processes, such as cold front, on heterogeneous underlying surfaces. Impacts of local circulation, such as lake breeze and valley breeze, on turbulent exchange process and its influence mechanism are revealed. The project improves understanding of the atmospheric boundary layer structure and turbulent transport characteristics of inhomogeneous underlying surfaces.

复杂地形非均匀下垫面大气边界层结构及湍流输送特征是目前大气科学尤其是大气边界层研究的热点和难点。本项目以高原湖泊洱海为研究对象，利用湖-气、陆-气通量多年连续的定位观测资料，结合湖气耦合模式，研究复杂地形下湖泊和农田不同下垫面近地面层湍流交换及大气边界层结构特征，分析湖泊对局地环流水平及垂直结构的影响，改进湖-气耦合模式中湖-气间能量和水分交换参数化方法，利用改进的湖-气耦合模式研究冷锋等天气过程对非均匀下垫面湍流交换的影响，揭示洱海地区湖陆风、山谷风局地环流对地气间湍流交换过程的影响及其影响机制，加深对非均匀下垫面大气边界层结构及湍流输送特征的认识。

高原湖区的湖-气相互作用研究，对于高原乃至全球的天气和气候变化预测有着重要意义。项目较好地执行了研究计划，完成了预定的研究内容，对高原湖区的湖-气交换过程有了更深入的理解，取得的主要研究成果如下：1.建立了高原湖泊洱海长期连续的高质量湖-气相互作用数据集，为研究高原湖泊湖-气相互作用特征提供了重要的数据基础。2.明确了高原湖区不同下垫面陆-气交换特征及其控制因子。3.改善了湖-气耦合模式对于浅湖的模拟偏差问题。4. 揭示了高原湖泊洱海对局地环流和边界层温度层结、湿度层结和近地面层湍流交换的影响与机制。项目执行期间共发表4篇SCI论文，同时培养1名博士生。