Opinion: Papers that shaped tropospheric chemistry Atmospheric Chemistry and Physics DOI 10.5194/acp-21-12909-2021 6 October 2021 Which published papers have transformed our understanding of the chemical processes in the troposphere and shaped the field of atmospheric chemistry? We explore how these papers have shaped the development of the field of atmospheric chemistry and identify the major landmarks in the field of atmospheric chemistry through the lens of those papers’ impact on science, legislation and environmental events. Read more
The long-term transport and radiative impacts of the 2017 British Columbia pyrocumulonimbus smoke aerosols in the stratosphere Atmospheric Chemistry and Physics DOI 10.5194/acp-21-12069-2021 22 September 2021 Interactions of extreme fires with weather systems can produce towering smoke plumes that inject aerosols at very high altitudes (> 10 km). Three such major injections, largest at the time in terms of emitted aerosol mass, took place over British Columbia, Canada, in August 2017. We model the transport and impacts of injected aerosols on the radiation balance of the atmosphere. Our model results match the satellite-observed plume transport and residence time at these high altitudes very closely. Read more
Better representation of dust can improve climate models with too weak an African monsoon Atmospheric Chemistry and Physics DOI 10.5194/acp-21-11423-2021 6 September 2021 Earth system models have persistent biases that impinge on our ability to make robust future regional predictions of precipitation. For the last 15 years, there has been little improvement in these biases. This work presents an accurate representation of dust absorption based upon observed dust mineralogical composition and size distribution. The striking result is that this more accurate representation improves tropical precipitations for climate models with too weak an African monsoon. Read more
Disparities in particulate matter (PM10) origins and oxidative potential at a city scale (Grenoble, France) – Part 2. Atmospheric Chemistry and Physics DOI 10.5194/acp-21-9719-2021 11 August 2021 With an enhanced source apportionment obtained in a companion paper, this paper acquires more understanding of the spatiotemporal associations of the sources of PM to oxidative potential (OP), an emerging health-based metric. Multilayer perceptron neural network analysis was used to apportion OP from PM sources. Results showed that such a methodology is as robust as the linear classical inversion and permits an improvement in the OP prediction when local features or non-linear effects occur. Read more
Investigations on the anthropogenic reversal of the natural ozone gradient between northern and southern midlatitudes Atmospheric Chemistry and Physics DOI 10.5194/acp-21-9669-2021 6 August 2021 The few ozone measurements made before the 1980s indicate that industrial development increased ozone concentrations by a factor of ~ 2 at northern midlatitudes, which are now larger than at southern midlatitudes. This difference was much smaller, and likely reversed, in the pre-industrial atmosphere. Earth system models find similar increases, but not higher pre-industrial ozone in the south. This disagreement may indicate that modeled natural ozone sources and/or deposition loss are inadequate. Read more
Smoke-charged vortices in the stratosphere generated by wildfires and their behaviour in both hemispheres: comparing Australia 2020 to Canada 2017 Atmospheric Chemistry and Physics DOI 10.5194/acp-21-7113-2021 30 June 2021 Following the 2020 Australian fires, it was recently discovered that stratospheric wildfire smoke plumes self-organize as anticyclonic vortices that persist for months and rise by 10 km due to the radiative heating from the absorbing smoke. In this study, we show that smoke-charged vortices previously occurred in the aftermath of the 2017 Canadian fires. We use meteorological analysis to characterize this new object in geophysical fluid dynamics, which likely impacts radiation and climate. Read more
Heterogeneous interactions between SO2 and organic peroxides in submicron aerosol Atmospheric Chemistry and Physics DOI 10.5194/acp-21-6647-2021 21 June 2021 Discrepancies between atmospheric modeling and field observations, especially in highly polluted cities, have highlighted the lack of understanding of sulfate formation mechanisms and kinetics. Here, we directly quantify the reactive uptake coefficient of SO2 onto organic peroxides and study the important governing factors. The SO2 uptake rate was observed to depend on RH, peroxide amount and reactivity, pH, and ionic strength, which provides a framework to better predict sulfate formation. Read more
Observing the timescales of aerosol–cloud interactions in snapshot satellite images Atmospheric Chemistry and Physics DOI 10.5194/acp-21-6093-2021 15 June 2021 Cloud responses to aerosol are time-sensitive, but this development is rarely observed. This study uses isolated aerosol perturbations from ships to measure this development and shows that macrophysical (width, cloud fraction, detectability) and microphysical (droplet number) properties of ship tracks vary strongly with time since emission, background cloud and meteorological state. This temporal development should be considered when constraining aerosol–cloud interactions with observations. Read more
Uncertainties in the Emissions Database for Global Atmospheric Research (EDGAR) emission inventory of greenhouse gases Atmospheric Chemistry and Physics DOI 10.5194/acp-21-5655-2021 10 June 2021 We conducted an extensive analysis of the structural uncertainty of the Emissions Database for Global Atmospheric Research (EDGAR) emission inventory of greenhouse gases, which adds a much needed reliability dimension to the accuracy of the emission estimates. The study undertakes in-depth analyses of the implication of aggregating emissions from different sources and/or countries on the accuracy. Results are presented for all emissions sectors according to IPCC definitions. EDGAR) emission inventory of greenhouse gases">Read more
Captured cirrus ice particles in high definition Atmospheric Chemistry and Physics DOI 10.5194/acp-21-7171-2021 2 June 2021 The cryo-electron microscopy images and analysis in this paper result from the first balloon-borne capture, preservation, and high-resolution imaging of ice particles from cirrus clouds. The images show cirrus particle complexity in unprecedented detail, revealing unexpected morphology, a mixture of surface roughness scales and patterns, embedded aerosols, and a large variety of habits within a single cloud. The results should inform ongoing efforts to refine modeling of cirrus radiative impact. Read more