基于MAX-DOAS观测技术探索外源大气污染物跨境输入青藏高原的机理

As an important barrier of global ecology security, the Tibet plateau is sensitive to global climate change. Even through the local emission is trivial, exogenous pollutants can transport into the Tibetan plateau, which destroy the ecological environment and increase the resource & environment burden with a rising trend. Currently, the observation-based evidence is very sparse because of extreme conditions, and the mechanism of air pollutants transportation to the Himalayas and Tibetan Plateau is still not fully quantified. In this proposal, we plan to derive time series of atmospheric pollutants (NO2, SO2, HCHO, O3 and aerosol) in China-Nepal border(Mt. Everest) based on multi-axis differential optical absorption spectroscopy (MAX -DOAS) observations. Furthermore, by focusing on pronounced pollutant transportation cases, we will determine the mechanism of air pollutants transportation to the Himalayas and Tibetan Plateau based MAX-DOAS observations, atmospheric circulation, meteorological elements, landform and the pollution characteristics in source area. This study can provide a valuable reference for solving air pollution in the Tibetan Plateau. In addition, it also present scientific evidence to refute western media which normally show prejudice on air pollution problem in the Tibetan Plateau.

青藏高原是全球气候变化的敏感地区，对我国乃至世界生态安全都具有重要的屏障作用。尽管自身污染排放较少，但外源污染可以传输进入青藏高原，破坏生态环境，增加资源、环境压力。受极端条件影响，现有观测研究尚不足以彻底理清外源大气污染物跨境输入青藏高原的机理。拟基于多轴差分光学吸收光谱技术（MAX-DOAS）在青藏高原中尼边境（珠峰地区）的潜在污染跨境传输通道上开展观测研究，获得大气污染物（NO2、SO2、HCHO、O3和气溶胶）的时空分布信息，以显著的污染物传输事件为突破口，结合大气环流、气象要素、地形地貌及源区污染特征，明晰外源大气污染物跨境输入青藏高原的源头、规模和规律，理清本地源排放、南亚污染跨国境传输和我国东部污染跨境传输的相对贡献，为青藏高原环境保护提供应对措施，同时也能以科学事实驳斥西方媒体对青藏高原环境污染成因的不实指责，维护国家利益。

青藏高原不但是“气-水-冰-土-人”多圈层体现最全、相互作用最强烈的地区，也是全球气候、环境变化的敏感地区，对我国乃至世界生态安全都具有重要的屏障作用。尽管当地人类活动少，自身排放污染物较少，仍是世界上除南极和北极之外最洁净的地区。但外源污染可以传输进入青藏高原，破坏生态环境，增加资源、环境压力。受极端条件影响，现有观测研究尚不足以彻底理清外源大气污染物跨境输入青藏高原的机理。本项目基于多轴差分光学吸收光谱技术（MAX-DOAS）在青藏高原中尼边境（珠峰地区）的潜在污染跨境传输通道上开展了观测研究，获得大气污染物（NO2、SO2、HCHO、O3）的时空分布信息，以显著的污染物传输事件为突破口，结合大气环流、气象要素、地形地貌及卫星遥感的源区污染特征，结合GEOS-Chem示踪模拟技术以及HYSPLIT后向轨迹分析技术，初步探索了外源大气污染物跨境输入青藏高原的源头、规模和规律，初步定性分析了本地源排放、南亚污染跨国境传输和我国东部污染跨境传输的相对贡献，得出青藏高原大气污染以外源输入为主，且具有很强的季节变化特性，本项目研究为青藏高原环境保护提供了应对措施，同时也能以科学事实驳斥西方媒体对青藏高原环境污染成因的不实指责，维护国家利益。