Methanesulfonic acid (MSA) contributes to atmospheric new particle formation and growth – Yu et al., Environ. Sci.: Atmos. 2026; https://doi.org/10.1039/d5ea00123d

Marine clouds are one of the most important regulators of global climate – however, they are also one of the biggest uncertainties in climate models. Two new studies recently published in Environmental Science: Atmospheres shed light on a previously overlooked driver of marine cloud formation: methanesulfonic acid. Two of the authors, Mr. Wenjuan Yu and Dr. Xu-Cheng He, from the University of Helsinki, have told us a bit more about the works: 

“Marine phytoplankton emit dimethylsulfide (DMS), a gas associated with the characteristic smell of the sea. When oxidised in the atmosphere, DMS produces sulfuric acid (SA) and methanesulfonic acid (MSA). Whereas SA is known to drive new particle formation and growth of the particles, the role of MSA has remained unclear until now. A recent study published in Nature [1] revealed that MSA is a previously overlooked driver of particle formation and growth in cold, pristine marine air. Our new study published in Environmental Science: Atmospheres [2] further identifies a key environmental control on this process: water. Experiments conducted under atmospherically relevant conditions in the CERN CLOUD chamber show that relative humidity strongly controls whether MSA contributes to particle growth. Between +10 °C and −10 °C, MSA contributes negligibly under very dry conditions but drives rapid additional growth when relative humidity exceeds approximately 50%. Even relatively small changes in humidity substantially alter particle growth rates.  

A complementary study also published in Environmental Science: Atmospheres  [3], by Hannah Klebach et al., investigates how MSA contributes to the initial formation of new particles in the presence of amines. CLOUD experiments at +5 °C an d −10 °C show that MSA can form new particles together with dimethylamine (DMA), although nucleation from MSA and DMA alone is relatively slow. However, when small amounts of SA are present, MSA strongly enhances particle formation, increasing nucleation rates by one to two orders of magnitude. Molecular measurements detect MSA, SA and DMA together in the initial clusters, demonstrating that MSA participates directly in the earliest stages of particle formation.  

Together, these findings strengthen the connection between marine biology, aerosol, atmospheric water and climate. By showing that MSA can contribute both to the formation of new particles under atmospherically relevant marine conditions and to their subsequent humidity-dependent growth, the two studies provide a more complete picture of how marine sulfur emissions can influence the atmospheric particle population. Newly formed particles must grow rapidly to survive and eventually become cloud condensation nuclei (CCN), the seeds on which cloud droplets form. As the climate warms, the atmosphere can hold more water vapour, potentially altering the conditions under which MSA contributes to particle formation and growth and, in turn, to the number of cloud seeds. An increase in the number of CCN might translate into brighter clouds, which therefore reflect more solar radiation back to space, thus exerting a cooling effect on the climate. However, current climate models do not fully capture MSA-related CCN formation processes correctly. These models may therefore underestimate natural CCN formation over polar oceans and in the cold free troposphere. Correctly representing both MSA-enhanced particle formation and the strong humidity dependence of MSA-driven growth is especially important as anthropogenic sulfur emissions decline and particles originating from natural marine emissions constitute a larger fraction of atmospheric aerosol. Therefore, these complementary findings provide the experimental basis needed to improve predictions of marine aerosol, cloud formation and their influence on the future climate.” 

[1] Baalbaki, J., Shen, J. et al. Role of methanesulfonic acid in atmospheric particle nucleation and growth. Nature (2026), DOI: 10.1038/s41586-026-10810-2.  

[2] Yu et al. Impact of humidity on aerosol growth from methanesulfonic acid. Environmental Science: Atmospheres (2026), DOI: 10.1039/d5ea00123d.  

[3] Klebach et al. Rapid new particle formation driven by methanesulfonic acid and amines. Environmental Science: Atmospheres (2026), DOI: 10.1039/d5ea00081e. 

The Editorial Office of Environmental Science: Atmospheres is excited to announce a special collection dedicated to the 22nd International Conference on Nucleation and Atmospheric Aerosols (ICNAA). This is the leading conference series in the wide field of nucleation and atmospheric aerosols.

We invite all researchers who will attend ICNAA 2025 to submit their papers for consideration in this special collection. It will encompass a broad range of topics, reflecting the diverse and cutting-edge research presented at the conference. The main topic areas of focus include:

Nucleation Theory & Experiment: Studies of homogeneous, heterogeneous and ion induced nucleation including single or multicomponent system cluster formation and properties, condensation, and evaporation, and experimental, theoretical and computational investigations as well as history of nucleation research.

Tropospheric & Stratospheric Aerosols: Fundamental processes associated with tropospheric and stratospheric aerosols, especially related to global warming, acid rain, air quality and multi-phase chemistry. Studies into aerosol concentrations and distributions, variability and long term trends. Focus on composition, hygroscopicity, thermodynamics, phase changes, physico-chemical and optical properties.

Cloud Drop and Ice Nucleation: Fundamental processes related to droplet and ice-crystal activation, growth, cloud condensation nuclei and ice nuclei origin, composition, spatial and temporal distributions and loadings, experimental and theoretical studies.

Aerosol-Climate Interactions: Direct and indirect effects of atmospheric aerosols on radiative forcing and climate, remote sensing and regional to global scale climate modelling of aerosol impacts and feedback systems.

This collection will be supported by our Guest Editors: Katrianne Lehtipalo, Zoran Ristovski, Neil Donahue and Paul Winkler. We look forward to your contributions to this themed collection, which will highlight the latest advancements and foster continued innovation in the field of atmospheric sciences. The submission deadline is December 31st 2025.

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When you publish with Environmental Science: Atmospheres you can:

• Put your trust in both our rigorous peer review process and fast times to publication – our average time to decision for peer-reviewed manuscripts is just 37 days.
• Expect your work to be promoted through our journal social media (@envsci.rsc.org ‬and LinkedIn)
• Be confident of a global audience for your work. This means that dissemination of this work will likely go beyond chemists and reach a broader audience.

Environmental Science: Atmospheres publishes high quality research in fundamental and applied atmospheric chemistry. The journal scope spans the entirety of Earth’s atmosphere, and studies addressing the interactions of indoor air pollutants with outdoor air, or considering human health effects, are encouraged. We offer authors the option to publish the peer review history alongside their article.

Article publication online and in issues will occur without delay to ensure the timely dissemination of the work. The articles will then be assembled on the RSC Publishing platform and promoted as a web-based thematic collection, to permit readers to consult and download individual contributions from the entire series.

If you’re interested, we invite you to submit your research today on our platform, quoting ‘EAICoNAA25’ in the ‘Comments to the Editor’ when submitting your manuscript. You can get in touch with the editorial office with any questions you may have about this collection.

We are delighted to announce that the Environmental Science: Atmospheres themed collection on air quality in emerging economic regions is now online.

Understanding the sources and composition of air pollutants in emerging economic regions is essential for implementing effective pollution control measures and mitigating the adverse impacts on human health and the environment. Addressing air quality issues in these regions is important for sustainable development, as poor air quality can impede economic growth and hinder progress towards achieving global environmental goals. This collection highlights the impactful atmospheric science research occurring in these regions.

Our collection was guest edited by Francis Pope (The University of Birmingham), Vinayak Sinha (Indian Institute of Science Education and Research Mohali), Michael Gatari (University of Nairobi).

Read the full issue online.

It includes:

Statistical assessment of an atmospheric mercury passive sampler at a regional site in South Africa

Kerneels Jaars et al.

Environ. Sci.: Atmos., 2025, Advance Article, DOI: 10.1039/D4EA00071D

Air pollution (PM_2.5) and its meteorology predictors in Kampala and Jinja cities, in Uganda

Gabriel Okello et al.

Environ. Sci.: Atmos., 2024,4, 1145-1156, DOI: 10.1039/D4EA00074A

Variability in air quality, ozone formation potential by VOCs, and associated air pollution attributable health risks for Delhi’s inhabitants

Mayank Pandey et al.

Environ. Sci.: Atmos., 2024,4, 897-910, DOI: 10.1039/D4EA00064A

Characterization of mercury in atmospheric particulate matter in the state of Rio de Janeiro, Brazil

Adriana Gioda et al.

Environ. Sci.: Atmos., 2024,4, 872-878, DOI: 10.1039/D4EA00044G

We hope that you enjoy reading this collection of articles. Please get in touch if you have any questions about this themed collection or want to contribute to the growing work on air quality in emerging economic regions.

We are delighted to announce that the Environmental Science: Atmospheres themed collection on peroxy radicals in the atmosphere is now online.

Understanding the chemistry and behaviour of peroxy radicals can help improve air quality models, leading to more accurate predictions of pollution levels and their impacts on human health and the environment. Additionally, peroxy radicals are key intermediates in atmospheric oxidation processes, influencing the atmospheric lifetime of greenhouse gases and contributing to climate change dynamics.

Our collection was guest edited by Carl Percival (California Institute of Technology), Barbara Nozière (KTH Royal Institute of Technology) and Lisa Whalley (University of Leeds).

Read the full issue online.

It includes:

Enhanced detection of aromatic oxidation products using NO₃− chemical ionization mass spectrometry with limited nitric acid

Olga Garmash and Matti Rissanen et al.

Environ. Sci.: Atmos., 2024, 4, 1368-1381, DOI: 10.1039/D4EA00087K

Towards automated inclusion of autoxidation chemistry in models: from precursors to atmospheric implications

Lukas Pichelstorfer et al.

Environ. Sci.: Atmos., 2024,4, 879-896, DOI: 10.1039/D4EA00054D

Interactions of peroxy radicals from monoterpene and isoprene oxidation simulated in the radical volatility basis set

Neil M. Donahue et al.

Environ. Sci.: Atmos., 2024,4, 740-753, DOI: 10.1039/D4EA00056K

Lifetimes of pre-reactive complexes of peroxy radicals revisited: thermostat effects, temperature dependence and highly oxygenated molecules

Christopher David Daub et al.

Environ. Sci.: Atmos., 2024,4, 732-739, DOI: 10.1039/D4EA00037D

We hope that you enjoy reading this collection of articles. Please get in touch if you have any questions about this themed collection or want to contribute to the growing work on peroxy radical chemistry.

The Editorial Office of Environmental Science: Atmospheres is excited to announce a special issue dedicated to the International Conference on Air Benefit and Cost and Attainment Assessment (ABaCAS) 2024. This prestigious conference, held annually, serves as a global forum for scientists to exchange knowledge and strategies related to air pollution control and the pathway to carbon neutrality.

We invite all researchers who present their work at ABaCAS 2024 to submit their papers for consideration in this special issue. This special issue will encompass a broad range of topics, reflecting the diverse and cutting-edge research presented at the conference. The nine tentative areas of focus include:

1. Emission inventory for atmospheric pollutants and greenhouse gases
2. Advancing technologies applied in source emission measurements
3. “Ground-air-space” monitoring for air pollutants and greenhouse gases
4. Air quality modelling and cost-benefit analysis for air pollution control
5. Roadmap to synergistic control of air pollutants and carbon
6. Urban air pollution control
7. Atmospheric environment and health
8. Big data and artificial intelligence in the atmospheric environment
9. Atmospheric haze chemistry

This collection will be supported by our Guest Editors: Dr Hongliang Zhang (Fudan University), Dr Song Guo (Peking University), Dr Biwu Chu (Chinese Academy of Sciences) and Dr Bo Zheng (Tsinghua University). We look forward to your contributions to this special issue, which will highlight the latest advancements and foster continued innovation in the field of atmospheric sciences. The submission deadline is November 30th 2025.

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

When you publish with Environmental Science: Atmospheres you can:

• Put your trust in both our rigorous peer review process and fast times to publication – our average time to decision for peer-reviewed manuscripts is just 38 days.
• Expect your work to be promoted through our journal social media (@EnvSciRSC and LinkedIn)
• Be confident of a global audience for your work. This means that dissemination of this work will likely go beyond chemists and reach a broader audience.

Environmental Science: Atmospheres publishes high quality research in fundamental and applied atmospheric chemistry. The journal scope spans the entirety of Earth’s atmosphere, and studies addressing the interactions of indoor air pollutants with outdoor air, or considering human health effects, are encouraged. We offer authors the option to publish the peer review history alongside their article.

Article publication online and in issues will occur without delay to ensure the timely dissemination of the work. The articles will then be assembled on the RSC Publishing platform and promoted as a web-based thematic collection, to permit readers to consult and download individual contributions from the entire series.

If you’re interested, we invite you to submit your research today on our platform, quoting ‘EAABaCAS24’ in the ‘Comments to the Editor’ when submitting your manuscript. You can get in touch with the editorial office with any questions you may have about this collection.

Submit your recent research on Solar Radiation Management to our new ES: Atmospheres collection! 

We invite you to contribute to our collection on Solar Radiation Management (SRM), also known as Solar Geoengineering. Understanding the mechanisms and potential impacts of SRM, as well as the broader field of solar geoengineering, can refine climate models, leading to more accurate projections of their efficacy and risks. SRM has the potential to reduce climate impacts globally, yet it also carries significant risks and uncertainties. For more information on the collection, which closes for submissions on 31 Jan 2025 , see our open call for papers.

When you publish with Environmental Science: Atmospheres you can:

• Put your trust in both our rigorous peer review process and fast times to publication – our average time to decision for peer-reviewed manuscripts is just 38 days.
• Expect your work to be promoted through our journal social media (@EnvSciRSC and LinkedIn)
• Be confident of a global audience for your work. This means that dissemination of this work will likely go beyond chemists and reach a broader audience.

Environmental Science: Atmospheres publishes high quality research in fundamental and applied atmospheric chemistry. The journal scope spans the entirety of Earth’s atmosphere, and studies addressing the interactions of indoor air pollutants with outdoor air, or considering human health effects, are encouraged. We offer authors the option to publish the peer review history alongside their article.

Article publication online and in issues will occur without delay to ensure the timely dissemination of the work. The articles will then be assembled on the RSC Publishing platform and promoted as a web-based thematic collection, to permit readers to consult and download individual contributions from the entire series.

If you’re interested, we invite you to submit your research today, quoting ‘EASRM24’ in the ‘Comments to the Editor’ when submitting your manuscript. You can get in touch with the editorial office with any questions you may have about this collection.

Environmental Science: Atmospheres is pleased to highlight the content that makes up our themed collection on ab initio reaction mechanisms. The full collection can be read here. In this blog, Associate Editor Stephen Klippenstein shares his thoughts on this topic and the articles published here:

The chemistry of the atmosphere is incredibly complex, with an enormous number of coupled reactions affecting key aspects of the atmosphere such as the concentration of aerosols. Various proposed responses to the global need for reducing our carbon emissions may dramatically alter emissions into the atmosphere. Quantitative models of the effect of such emissions are urgently needed. Such models rely on ever more detailed and accurate descriptions of a wide variety of elementary reactions. Ab initio studies of reaction mechanisms are a major contributor to the remarkable progress in our understanding of complex atmospheric reaction mechanisms.

This mini collection of articles provides three topical examples of the community efforts to advance our abilities to accurately model reaction mechanisms. The paper by Nguyen and Stanton on “Ab initio rate coefficients for the reaction of OH and H₂O₂ under troposphere and lower stratosphere conditions” demonstrates the utility of benchmark ab initio kinetics in mapping the rate constants for a simple but important reaction across wide ranges of temperature and pressure. There is an urgent to understand the global warming potentials of the molecules arising from the degradation of hydrofluoroolefins, which are a new class of refrigerants that are rapidly growing in importance. The paper by Watson and Beames on “Bimolecular sinks of Criegee intermediates derived from hydrofluoroolefins – a computational analysis” uses ab initio kinetics to map out a number of the key reaction rates and pathways for this new class of molecules. Highly oxygenated molecules, which are formed from the oxidation of various hydrocarbons, are important precursors to the formation of aerosols. The chemistry involved in the formation of such molecules is poorly understood. The reaction of two RO₂ radicals provides one route to molecular growth that is expected to contributed to highly oxygenated molecule formation. The paper by Murphy et al. on “Accretion product formation in the self-reaction of ethene-derived hydroxy peroxy radicals” explores this chemistry in detail for a prototypical atmospheric hydrocarbon radical.

We hope you find these articles interesting. If you would like to contribute work on a similar topic, please feel free to send a proposal to esatmospheres-rsc@rsc.org, where a member of our editorial team will be happy to help.