Multi-Satellite Air Quality Sulfur Dioxide (SO2) Database Long-Term L4 Global V2 (MSAQSO2L4) at GES DISC

These data are a part of Multi-Decadal Sulfur Dioxide (SO2) Climatology from Satellite Instruments (MEaSUREs-12-0022 project). Version 2 of the global catalogue of emissions from large SO2 point sources combines data from the Ozone Monitoring Instrument (OMI) on NASA's EOS Aura spacecraft, the Ozone Mapping and Profiler Suite (OMPS) on the NASA-NOAA Suomi National Polar-orbiting Partnership (SNPP), and the TROPOspheric Monitoring Instrument (TROPOMI) on the ESA/Copernicus Sentinel-5 Precursor (S-5P) spacecraft.

The catalogue MSAQSO2L4 file contains the site coordinates, source type, country, source name, annual SO2 emissions, annual emission uncertainties, and the number of satellite pixels in the fitting area for three satellite instruments as well as for their weighted average.

The emission estimates are based on operational version 2 OMI and OMPS Principal Component Analysis (PCA) retrieval algorithm SO2 slant column density (SCD) data (Li et al., 2020) as well as on new TROPOMI Covariance-Based Retrieval Algorithm (COBRA) SCD data (Theys et al., 2021). A single time-independent site-specific Air-Mass Factor (AMF) value for each site was calculated (McLinden et al., 2014) and applied consistently to each satellite SCD dataset to derive SO2 vertical column densities (VCDs=SCDs/AMFs). The emission estimate method is based on a fit of satellite VCDs to an empirical plume model developed to describe the SO2 spatial distribution near emission point sources. The plume model assumes that the SO2 concentrations emitted from a point source decline exponentially with distance and that they are affected by turbulent diffusion that can be described by a two-dimensional (2D) exponentially modified Gaussian function. The total SO2 mass is derived from the fit and the annual emission rate is calculated as the ratio between the total mass and the prescribed SO2 lifetime.

本数据集为多年代际二氧化硫（SO2）气候学卫星仪器数据集（MEaSUREs-12-0022项目）的一部分。该全球二氧化硫大型点源排放目录的第二版，融合了美国宇航局EOS Aura航天器上的臭氧监测仪器（OMI）、美国宇航局-国家海洋和大气管理局苏omi极地轨道伙伴关系（SNPP）上的臭氧测绘和轮廓仪（OMPS）以及欧洲航天局/哥白尼哨兵-5前驱器（S-5P）航天器上的对流层监测仪器（TROPOMI）所收集的数据。MSAQSO2L4目录文件包含了三个卫星仪器及其加权平均的站点坐标、源类型、国家、源名称、年度SO2排放量、年度排放不确定性以及拟合区域的卫星像素数量。排放估计基于操作版2的OMI和OMPS主成分分析（PCA）算法得到的SO2斜向柱密度（SCD）数据（Li等人，2020年）以及新的TROPOMI协方差检索算法（COBRA）SCD数据（Theys等人，2021年）。每个站点计算了一个单一的不随时间变化的特定站点空气质量因子（AMF）值（McLinden等人，2014年），并一致应用于每个卫星SCD数据集，以推导SO2垂直柱密度（VCDs=SCDs/AMFs）。排放估计方法基于将卫星VCDs与用于描述排放点源附近SO2空间分布的经验性烟羽模型拟合。烟羽模型假定来自点源的SO2浓度随距离指数衰减，并受到可由二维（2D）指数修正高斯函数描述的湍流扩散的影响。总SO2质量由拟合得出，年度排放率通过总质量与规定的SO2寿命之比计算得出。