Non-Technical Summary
This article explores air pollution as a globally connected issue using the telecoupling lens, which links distant regions through environmental and human systems. It shows how pollution connects Africa and the Global North, demonstrating that actions in one place affect people and air quality elsewhere. Drawing on 90 research sources, it looks at how satellite data helps monitor air quality and finds that most studies focus on natural sciences, with limited input from social sciences and less frequently from African researchers. The authors highlight the need to close data gaps and call for more inclusive, cross-disciplinary, and international cooperation in air quality research. Overall, the study pushes for fairer, more connected approaches to understanding and tackling air pollution worldwide.

Technical Summary
Air quality (AQ) is a transboundary phenomenon resulting from globalized interactions between coupled human and natural systems. Drawing on the telecoupling framework, this article argues that pollution flows, socioeconomic systems, and policy responses interconnect Africa with the Global North and identifies important data gaps for better understanding these interconnections. Through a meta-synthesis of 90 academic and gray literature sources, we analyze the use of satellite data for air quality monitoring, with a particular focus on interdisciplinary collaboration and African scientific participation. Our findings highlight a strong reliance on natural science approaches, limited integration of social science perspectives, and ongoing marginalization of African voices in shaping research agendas. We argue for a transformative research agenda rooted in interdisciplinary integration, inter-regional collaboration, and data justice. By adopting a telecoupled lens and prioritizing inclusive development, this study provides new pathways to understand, measure, and address air pollution as a global issue with deeply local consequences.

Social Media Summary
Air pollution links Africa & the Global North–study urges data justice & inclusive, global cooperation.

The aim of this paper is to highlight how TROPOspheric Monitoring Instrument (TROPOMI) trace gas data can best be used and interpreted to understand event-based impacts on air quality from regional to city scales around the globe. For this study, we present the observed changes in the atmospheric column amounts of five trace gases (NO2, SO2, CO, HCHO, and CHOCHO) detected by the Sentinel-5P TROPOMI instrument and driven by reductions in anthropogenic emissions due to COVID-19 lockdown measures in 2020. We report clear COVID-19-related decreases in TROPOMI NO2 column amounts on all continents. For megacities, reductions in column amounts of tropospheric NO2 range between 14g % and 63g %. For China and India, supported by NO2 observations, where the primary source of anthropogenic SO2 is coal-fired power generation, we were able to detect sector-specific emission changes using the SO2 data. For HCHO and CHOCHO, we consistently observe anthropogenic changes in 2-week-Averaged column amounts over China and India during the early phases of the lockdown periods. That these variations over such a short timescale are detectable from space is due to the high resolution and improved sensitivity of the TROPOMI instrument. For CO, we observe a small reduction over China, which is in concert with the other trace gas reductions observed during lockdown; however, large interannual differences prevent firm conclusions from being drawn. The joint analysis of COVID-19-lockdown-driven reductions in satellite-observed trace gas column amounts using the latest operational and scientific retrieval techniques for five species concomitantly is unprecedented. However, the meteorologically and seasonally driven variability of the five trace gases does not allow for drawing fully quantitative conclusions on the reduction in anthropogenic emissions based on TROPOMI observations alone. We anticipate that in future the combined use of inverse modeling techniques with the high spatial resolution data from S5P/TROPOMI for all observed trace gases presented here will yield a significantly improved sector-specific, space-based analysis of the impact of COVID-19 lockdown measures as compared to other existing satellite observations. Such analyses will further enhance the scientific impact and societal relevance of the TROPOMI mission.

This overview paper highlights the successes of the Ozone Monitoring Instrument (OMI) on board the Aura satellite spanning a period of nearly 14 years. Data from OMI has been used in a wide range of applications and research resulting in many new findings. Due to its unprecedented spatial resolution, in combination with daily global coverage, OMI plays a unique role in measuring trace gases important for the ozone layer, air quality, and climate change. With the operational very fast delivery (VFD; direct readout) and near real-time (NRT) availability of the data, OMI also plays an important role in the development of operational services in the atmospheric chemistry domain.