干旱半干旱区陆-气相互作用的观测研究

Arid and semi-arid areas are the sensitive zone in global change, and has significant impact on regional and global environment and climate change. Therefore, investigating the mechanism of land-atmosphere interactions in this regions has important significance. In this project, the long term monitoring and intensify experiment of land-atmosphere interaction will be carried on different underlying surface, over arid and semi-arid areas in northwest China. The character of energy, hydrology cycle and material exchange in different underlying surface over arid and semi-arid areas will be analyzed, and the key parameters of land surface processes will be established by using this ground-based observation, associate with the synergy observation data, flux net dataset, satellite remote sensing and simulation data. Furthermore, the contribution of land-atmosphere interaction in enhanced semi-arid warming will be studied, and its mechanism in arid and semi-arid area will be explored by the high quality dataset. This project can provide the important observation dataset for satellite remote sensing, and improve land surface simulation and our understanding of the aridity trend of arid and semi-arid regions.

干旱半干旱区是全球变化的敏感带，对区域甚至全球的生态环境和气候变化有着重大影响。因而，探讨该区域陆-气相互作用的机制有着重要意义。本项目拟在我国西北干旱半干旱区（敦煌和兰州）开展不同典型下垫面陆-气相互作用的长期连续观测和野外加强观测，结合我国北方协同观测资料、全球通量网、卫星遥感和模式模拟资料，分析干旱半干旱区不同典型下垫面的能量、水分循环和物质交换特征，确立该区域不同地表类型的关键参数，探讨陆-气相互作用对干旱半干旱区显著增温的贡献及其在干旱化趋势中的变化规律。该项目的实施可为卫星反演提供重要的地面观测资料，改善陆面模式模拟效果，加深我国对干旱半干旱区干旱化趋势的理解。

干旱半干旱区是全球变化的敏感带，对区域甚至全球的生态环境和气候变化有着重大影响，探讨该区域陆-气相互作用的机制有着重要意义。本项目通过在我国西北干旱半干旱区（敦煌和兰州）开展不同典型下垫面陆-气相互作用的长期连续观测和野外加强观测，并收集了榆中、景泰、兴隆山、敦煌等区域开展的一系列陆-气观测试验数据，建立了可用于分析我国西北干旱半干旱区域陆-气相互作用特征的长期连续和短期加强观测的试验数据集；结合地面观测资料、全球通量网、卫星遥感和模式模拟资料，获得了干旱半干旱区典型下垫面的能量、水分循环和物质交换特征，以及不同下垫面类型地表反照率的变化特征，并通过对比观测数据和气候模式模拟结果，证实气候系统模式明显低估了全球的干旱演变速率，提出了陆-气相互作用对干旱区加速扩张的反馈机制。该项目的实施加深了对干旱半干旱区干旱化趋势的理解，提高了对温室气体减排和全球荒漠化防治紧迫性的认识。