对流层臭氧是一种重要的温室气体，影响着辐射平衡与全球气候，同时也是最重要的光化学污染物，浓度高时危害植被和人类健康。臭氧浓度是影响大气氧化能力的重要指标。研究对流层臭氧及其前体物污染水平、变化规律、光化学过程和输送过程对评估其气候、环境和健康影响具有重要的科学意义。青藏高原对我国乃至全球的天气、气候都存在非常重要的影响。由于高原空气清洁，臭氧浓度主要受各种输送过程的影响。过去的研究显示高原不同地区的臭氧季节变化特征并不一致，而各种尺度不同的输送过程以及局地光化学过程对这些季节变化规律的影响仍是未知的。本项目拟在青藏高原由北向南的3-4个站点对臭氧及其前体物开展同步观测，并结合气象等辅助数据深入地探讨平流层输送、不同方向的水平输送过程以及局地光化学过程对不同季节和纬度青藏高原地面臭氧浓度贡献，及其对臭氧季节变化规律的影响。深入研究不同影响因子的相对重要性，加深对青藏高原臭氧变化机制的理解。

Tropospheric ozone is one of the most important greenhouse gases, influencing the global radiative balance and climate variability. Ozone is also an important photochemical pollutant and is damaging for vegetation and human health under high concentrations. The concentration of ozone is a critical factor influencing the atmospheric oxidation capacity. The study of the concentration level of tropospheric ozone, its variation characteristics, photochemistry and transport processes is highly needed for climate, environment and human health assessments. The Tibetan plateau is of crucial importance to the weather and climate in China and that around the globe. The air on the plateau is highly pristine, which is why ozone concentrations are mostly influenced by various transport processes. Past studies of various observation sites on the Tibetan plateau have revealed distinct ozone seasonal variation characteristics, however, the impact of transport processes at different scales and that of local photochemistry on the seasonal variation of ozone is still unknown. This project aims to study the contribution of stratospheric ozone input, transport from various directions and that of local photochemistry on the variation of ozone during different seasons and at different latitudes by making synchronized and continuous measurements of ozone and its precursors at 3-4 stations distributed from north to south of the plateau. Through the investigation on the relative importance of various influencing factors, we aim to gain a better understanding on the variation characteristics of ozone in the Tibetan plateau.