Open research questions in Atmospheric chemistry and aerosols

What the literature leaves open

• Traditional approaches are unable to capture changes in the chemical character of the atmosphere. There is a need for a framework to identify and diagnose evolutions within the pollutants of the atmosphere. The relationships between co-emitted species, the balance of photochemical processing, and the combustion fingerprint of emission sources are not well understood.

  Characterising Multivariate Air Pollution State Evolution in an Urban Atmosphere Using Deep-Learned Baseline Representations: London · 2026 · DOI

• Investigation of the reaction mechanism under various atmospheric conditions, - Study of the effects of different OVOCs on the reaction pathway, - Examination of the role of microdroplet interface in other atmospheric chemical reactions

  Rapid spontaneous generation of organosulfur from inorganic sulfur in atmospheric microdroplets · 2026 · DOI

• Further studies are needed to understand the impact of Amazonian super-micron particles on cirrus cloud formation and the planetary radiative balance. Research on the sources and properties of super-micron particles in northwestern Amazonia is necessary. Investigations on the effects of different temperatures and RH ice on ice nucleation by super-micron particles are required

  Super micron Amazonian aerosol particles as efficient catalyzers at cirrus temperatures · 2026 · DOI

• The lack of quantitative deposition ice nucleation measurements in northwestern Amazonia. The limited understanding of the ice nucleating abilities of aerosol particles in this region. The need to study the thermodynamic conditions relevant to mixed-phase and cirrus clouds during biomass burning and rainy seasons.

  Super micron Amazonian aerosol particles as efficient catalyzers at cirrus temperatures · 2026 · DOI

• further evaluation of SICMA in different environments and conditions, - investigation of the impact of organic nitrate chemistry on HCHO production, - development of more complex and accurate chemical mechanisms

  A simplified isoprene oxidation mechanism for fast formaldehyde-based emission inversion of isoprene · 2026 · DOI

• The complex chemistry involved in isoprene oxidation and its associated high computational cost. The need for a simplified mechanism that can accurately reproduce HCHO production and oxidant recycling. The limitation of adjoint-based inversions of isoprene emissions due to the complex chemistry involved.

  A simplified isoprene oxidation mechanism for fast formaldehyde-based emission inversion of isoprene · 2026 · DOI

• The study only considers a specific region (Northeast China), - The model simulation period is limited to 13 days, - The study relies on simulated data rather than real-world observations

  Numerical modeling on the mechanisms of chlorine chemistry in snowpack and their impact on secondary atmospheric pollution · 2026 · DOI

• Further research is needed to quantify the impact of N2O5 absorption coefficient and ClNO2 yield at different interfaces, - Studies should investigate the contribution of ClNO2 to pollutants formation in other regions, - Research should focus on developing more accurate and representative aerosol schemes

  Numerical modeling on the mechanisms of chlorine chemistry in snowpack and their impact on secondary atmospheric pollution · 2026 · DOI

• Further research is needed to improve the parametrizations for the temperature dependency of evaporative AVOC emissions, - Studies should investigate the impact of emission control policies on AVOC emissions, - Research should focus on developing more accurate models that account for the temperature dependence of AVOC emissions

  Temperature-Dependent Evaporative Anthropogenic VOC Emissions Significantly Exacerbate Regional Ozone Pollution · 2024 · DOI

• The temperature dependence of evaporative AVOC emissions has not been assessed on a regional scale. The impact of temperature-dependent AVOC emissions on surface ozone pollution is not well understood. There is a need to better understand the mechanisms by which surface ozone pollution occurs in Chinese cities.

  Temperature-Dependent Evaporative Anthropogenic VOC Emissions Significantly Exacerbate Regional Ozone Pollution · 2024 · DOI

• Training that treats Atmospheric Chemistry and the Ozone Story as a settled body of findings misrepresents its condi- tion; training that treats it as all open questions fails to convey what has been secured.

  The Shield That Nearly Cracked: A Historical Development Review of Atmospheric Chemistry and the Ozone Story · 2026 · DOI

• The mechanisms underlying the formation and atmospheric abundance of organosulfur compounds are not well understood. The role of microdroplet interface in organosulfur formation is not well understood.

  Rapid spontaneous generation of organosulfur from inorganic sulfur in atmospheric microdroplets · 2026 · DOI

• The photooxidation of SO 2 on organic carbon (OC) is a critical pathway for sulfate formation, yet the role of interactions between OC and transition metal ions (TMIs) in this process remains scarcely understood.

  Complexation strength between organic carbon and transition metal ions dominates the photochemical conversion of SO 2 to sulfates · 2026 · DOI

• Abstract Estuarine‐shelf systems contribute substantially to global dimethyl sulfide (DMS) emissions, yet the seasonal dynamics and cycling processes of DMS in these regions remain poorly understood.

  Seasonal Dynamics of Marine Dimethylsulfide in the Yangtze River Estuary: Production, Loss, and Environmental Drivers · 2025 · DOI

• 5 improvement, leaving comprehensive strategies for tackling all three underexplored.

  Strategy for coordinating near-term PM 2.5 , ozone, and CO 2 mitigation in China · 2025 · DOI

• In current emission inventories, postfertilization soil emissions are poorly characterized due to inaccurate identification of fertilization timing and location.

  Enhanced Soil Emissions of Reactive Nitrogen Gases by Fertilization and Their Impacts on Secondary Air Pollution in Eastern China · 2025 · DOI

• Accelerated reactions in microdroplets have gained significant attention, but whether or not NO 2 hydrolysis is accelerated in deliquesced particles remains unclear.

  Evidence on Interfacial Reaction Governing NO2 Hydrolysis in Deliquesced Aerosol Particles · 2025 · DOI

• However, the kinetics and mechanisms of HMS formation in aqueous aerosols remain poorly understood.

  Ionic Strength Inhibits the Multiphase Reaction Rate between Dissolved SO2 and HCHO in Aqueous Aerosols: Implications for Sources of Atmospheric Hydroxymethanesulfonate · 2025 · DOI

• Few studies have examined the ClNO2 chemistry from the perspective of the planetary boundary layer.

  Vertical Gradient of Nitryl Chloride and Implications for Atmospheric Photochemistry in Pearl River Delta, China, during Wintertime · 2025 · DOI

• However, the limited knowledge of sources and nature of these chemicals challenges sampling decisions.

  Development of a sampling protocol for collecting leaf surface material for multiphase chemistry studies · 2024 · DOI

• The hydroxyl radical (OH) is the central oxidant in Earth's troposphere, but its temporal variability is poorly understood.

  Interannual changes in atmospheric oxidation over forests determined from space · 2024 · DOI

• Despite its importance, the multiphase photochemistry of BBOA after light absorption remains poorly understood due to challenges in determining the oxidant concentrations and the reaction kinetics within aerosol particles.

  Biomass-burning organic aerosols as a pool of atmospheric reactive triplets to drive multiphase sulfate formation · 2024 · DOI

• High Resolution Image Download MS PowerPoint Slide Oxygenated volatile organic compounds (OVOCs) significantly modulate atmospheric chemistry, but the sources and air quality impacts of OVOCs in aged urban outflows remain to be elucidated.

  Significant Biogenic Source of Oxygenated Volatile Organic Compounds and the Impacts on Photochemistry at a Regional Background Site in South China · 2024 · DOI

• The linkages between BrC optical properties and chemical composition remain inadequately understood, with quantified chromophores explaining less than 25% of ambient aerosol light absorption.

  Predictions of the Optical Properties of Brown Carbon Aerosol by Machine Learning with Typical Chromophores · 2024 · DOI

• However, photochemical transformations of aromatic carbonyl photosensitizers, particularly in multicomponent systems, are understudied.

  Aqueous-Phase Photoreactions of Mixed Aromatic Carbonyl Photosensitizers Yield More Oxygenated, Oxidized, and less Light-Absorbing Secondary Organic Aerosol (SOA) than Single Systems · 2024 · DOI

Most-cited papers in Atmospheric chemistry and aerosols

• High secondary aerosol contribution to particulate pollution during haze events in China · Nature · 2014 · 4,078 citations
• Evolution of Organic Aerosols in the Atmosphere · Science · 2009 · 3,626 citations
• Aerosols, Climate, and the Hydrological Cycle · Science · 2001 · 3,357 citations
• Strong radiative heating due to the mixing state of black carbon in atmospheric aerosols · Nature · 2001 · 2,126 citations
• Biomass Burning in the Tropics: Impact on Atmospheric Chemistry and Biogeochemical Cycles · Science · 1990 · 2,104 citations
• Global Estimates of Ambient Fine Particulate Matter Concentrations from Satellite-Based Aerosol Optical Depth: Development and Application · Environmental Health Perspectives · 2010 · 1,476 citations
• Greenhouse gases emissions and global climate change: Examining the influence of CO2, CH4, and N2O · The Science of The Total Environment · 2024 · 910 citations
• Use of Satellite Observations for Long-Term Exposure Assessment of Global Concentrations of Fine Particulate Matter · Environmental Health Perspectives · 2014 · 754 citations
• Global warming: review on driving forces and mitigation · Environmental Progress & Sustainable Energy · 2018 · 699 citations
• Investigation of the sources and evolution processes of severe haze pollution in Beijing in January 2013 · Journal of Geophysical Research Atmospheres · 2014 · 630 citations

Most recent work

• Global NO 2 changes between 2019 and 2024 as observed by TROPOMI in urban areas and emerging hotspots · Atmospheric Chemistry and Physics · 2026
• Interplay of chemistry, meteorology, and transport in modulating Surface ozone over a tropical coastal semi-urban site in Southern India · Journal of Atmospheric Chemistry · 2026
• A novel short-pathlength photoreactor to study aqueous-phase photochemistry: application to biomass-burning phenols · Atmospheric Measurement Techniques · 2026
• Inferring drivers of tropical isoprene: competing effects of emissions and chemistry · Atmospheric chemistry and physics · 2026
• Supplementary material to "ORACLE-lite (v3.0): A reduced-complexity module for simulating organic aerosol formation and evolution in long term chemistry-climate simulations" · 2026
• Diurnal and Seasonal Variability of Gas–Particle Partitioning of Secondary Organic Aerosols in the Tropical Atmosphere · ACS Earth and Space Chemistry · 2026
• Delhi cannot clean its air alone: airshed-scale mitigation outperforms local controls even under unfavourable winter meteorology · npj Clean Air · 2026
• The Dependence of Emissions-based Anthropogenic Aerosol ERFs on Background Composition and Meteorological States in the GFDL-ESM4.1 Model · 2026
• Long-term characterisation and discrimination of aerosol types across Africa using AERONET observations (1998–2024) · Journal of Atmospheric and Solar-Terrestrial Physics · 2026
• O 3 –NO x –VOCs sensitivity in major Chinese regions: detailed insights from GEMS satellite hourly observations · Atmospheric chemistry and physics · 2026

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