基于卫星平台的全球大气一氧化碳柱浓度反演方法及结果分析

摘要

温室效应是全球气候变化的主要原因之一，除温室气体外，有毒气体一氧化碳(CO)作为一种非直接温室气体加剧了这种变化。由于地基观测台站数量有限，而大气化学模型的模拟又很大程度上依赖于模型假定，因此，卫星观测成为实时获取大气CO浓度分布信息的有效途径。 Sciamachy是第一台搭载在卫星上，利用观测到的近红外波段太阳反射光谱反演大气一氧化碳的仪器。由于在近红外波段，大气散射效应可以忽略，所以Sciamachy观测数据能够很好地反演与人类活动息息相关的大气底层一氧化碳的时空变化信息。本文基于迭代最大后验概率算法，对Sciamachy的观测数据进行反演分析，同时应用云效应校正与仪器本身问题校正方法，得到了全球一氧化碳柱浓度时空分布结果；通过与Atsr全球火点数据的比较，分析了全球CO排放源的种类与时空分布；最后选取中国地区CO柱浓度分布图，并结合人口密度与煤田/煤矿分布，对其排放源进行了初步推断。%Greenhouse effect is one of the main reasons for climate change. Carbon monoxide (CO) is a critical air pollutant because of its short-term harmful health effects. Furthermore, since CO emission has a global warming potential, it exacerbats the climate change as an indirect greenhouse gas. Due to the fact that the number of ground-based stations is less and the chemical model simulation is greatly dependent on assumption, satellite observation becomes the effective way to acquire the information about CO distribution. Sciamachy is the first satellite instrument to allow retrieval of CO by measuring absorption in the near infrared region from reflected and scattered sunlight, which is highly sensitive to the lower layers of the troposphere where the sources, such as biomass burning, are located, and where the bulk of the gases is usually found. In this study the Sciamachy CO vertical column density is successfully inversed;after applying the instrument and cloud correction, yearly and seasonal results are presented. Finally by comparing them with the fire counts of ATSR dataset and the distributions of population density and coal mines, the CO emission sources are preliminary deduced.