There are several different types of sources responsible for the emissions of carbon monoxide (CO), sulphur dioxide (SO2), nitrogen dioxide (NO2) and aerosols in Africa. These emissions make the African continent vulnerable to the impacts on climate change, human health and the environment. It has been shown that the southern African emissions are dominant in the winter season (JJA). However, few studies have been done to study the winter and spring season in unison to understand these emissions. Therefore, in this study, both satellite data, such as Sentinel-5P and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO), and reanalysis data from Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2), were used to study emissions in the 2019 JJASO period. Furthermore, the sequential Mann-Kendall (SQMK) test was used to study the trends of SO2, CO, Angstrom exponent and UV aerosol index data during the 2019 JJASO period. The results from sentinel-5P showed the dominance of CO and NO2 in the Democratic Republic of the Congo (DRC) and dominance of SO2 and NO2 in the Republic of South Africa (RSA). These emissions were largely from wildfires and coal-fired power stations, respectively. However, an SO2 hot spot was also observed over the DRC region which was found to be from an active volcano. CALIPSO data agreed with these observations and further showed the maximum vertical distribution of these aerosols and gases to be at ~ 2 km. The SQMK test of Angstrom exponent and UV aerosol index showed that aerosol dominance from emissions change during the JJASO period. Therefore, studying the JJASO period does give a better understanding of emissions in southern Africa.

中文翻译：

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2019 年 JJASO 期间观察到的南部非洲有毒气体和气溶胶的排放

在非洲，一氧化碳 (CO)、二氧化硫 (SO2)、二氧化氮 (NO2) 和气溶胶的排放有几种不同类型的来源。这些排放使非洲大陆容易受到气候变化、人类健康和环境的影响。已经表明，南部非洲的排放量在冬季 (JJA) 中占主导地位。然而，很少有研究同时研究冬季和春季以了解这些排放。因此，在本研究中，卫星数据，如 Sentinel-5P 和云气溶胶激光雷达和红外探路者卫星观测 (CALIPSO)，以及现代时代研究与应用回顾性分析第 2 版 (MERRA-2) 的再分析数据)，用于研究 2019 年 JJASO 期间的排放。此外，采用序贯 Mann-Kendall (SQMK) 检验研究 2019 年 JJASO 期间 SO2、CO、埃指数和紫外线气溶胶指数数据的趋势。sentinel-5P 的结果显示，刚果民主共和国 (DRC) 中 CO 和 NO2 占主导地位，南非共和国 (RSA) 中 SO2 和 NO2 占主导地位。这些排放主要分别来自野火和燃煤发电站。然而，在刚果民主共和国地区也观察到一个 SO2 热点，发现它来自一座活火山。CALIPSO 数据与这些观察结果一致，并进一步显示这些气溶胶和气体的最大垂直分布在约 2 公里处。埃指数和紫外线气溶胶指数的 SQMK 检验表明，在 JJASO 期间，排放的气溶胶优势发生了变化。所以，