Trace gases and aerosols in the Arctic, which typically originate from midlatitude and tropical emission regions, modulate the Arctic climate via their radiative and chemistry impacts. Thus, long-range transport of these substances is important for understanding the current and the future change of Arctic climate. By employing chemistry–climate models, we explore how year-to-year variations in the atmospheric circulation modulate atmospheric long-range transport into the Arctic.

The formation pathways of nitrogen-containing compounds (NOCs) in the atmosphere remain unclear. We investigated the composition of aerosols and fog water by state-of-the-art mass spectrometry and compared the formation pathways of NOCs. We found that NOCs in aerosols were mainly formed through nitration reaction, while ammonia addition played a more important role in fog water. The results deepen our understanding of the processes of organic particulate pollution.

The determination of ions in the mass spectra of individual particles remains uncertain. We have developed a standard-free mass calibration algorithm applicable to more than 98 % of ambient particles. With our algorithm, ions with ~ 0.05 Th mass difference could be determined. Therefore, many more atmospheric species could be determined and involved in the source apportionment of aerosols, the study of chemical reaction mechanisms, and the analysis of single-particle mixing states.

We reveal a significant mechanism of stratospheric O₃ intrusion (SI) into the atmospheric environment induced by an extratropical cyclone system. This system facilitates the downward transport of stratospheric O₃ to the near-surface layer by vertical coupling, involving the upper westerly trough, the middle northeast cold vortex, and the lower extratropical cyclone in the troposphere. On average, stratospheric O₃ contributed 26.77 % to near-surface O₃ levels over the North China Plain.

The Geostationary Environment Monitoring Spectrometer (GEMS) provides hourly measurements of NO₂. We use the chemical transport model to find how emissions, chemistry, and transport drive the changes in NO₂ observed by GEMS at different times of the day. In winter, the chemistry plays a minor role, and high daytime emissions dominate the diurnal variation in NO₂, balanced by transport. In summer, emissions, chemistry, and transport play an important role in shaping the diurnal variation in NO₂.

Climate models are crucial for predicting climate change in detail. This paper proposes a balanced approach to improving their accuracy by combining traditional process-based methods with modern artificial intelligence (AI) techniques while maximizing the resolution to allow for ensemble simulations. The authors propose using AI to learn from both observational and simulated data while incorporating existing physical knowledge to reduce data demands and improve climate prediction reliability.

The anthropogenic fraction of non-methane volatile organic compound (NMVOC) emissions associated with biogenic sources (e.g., terpenes) is investigated based on eddy covariance observations. The anthropogenic fraction of terpene emissions is strongly dependent on season. When analyzing volatile chemical product (VCP) emissions in urban environments, we caution that observations from short-term campaigns might over-/underestimate their significance depending on local and seasonal circumstances.

Organic aerosol is ubiquitous in the atmosphere and largely explains the gap between current levels of fine particulate matter in many cities and the World Health Organization guideline values. This study highlights the dominant contributions of cooking emissions to organic aerosol when marine air prevailed in Hong Kong, which were occasionally overwhelmed by aromatics-derived secondary organic aerosol in continental ouflows.

Emissions of reactive organic gases from industrial volatile chemical product sources are measured. There are large differences among these industrial sources. We show that oxygenated species account for significant contributions to reactive organic gas emissions, especially for industrial sources utilizing water-borne chemicals.

Microphysical characteristics of convective overshooting are essential but poorly understood, and we examine them by using the latest data. (1) Convective overshooting events mainly occur over NC (Northeast China) and northern MEC (Middle and East China). (2) Radar reflectivity of convective overshooting over NC accounts for a higher proportion below the zero level, while the opposite is the case for MEC and SC (South China). (3) Droplets of convective overshooting are large but sparse.

In this work, we assess and evaluate benzene, toluene, and xylene primary emissions and air quality levels in Spain by combining observations, emission inventories, and air quality modelling techniques. The comparison between modelled and observed levels allows identifying uncertainty sources within the emission input. This contributes to improving air quality models' performance when simulating these compounds, leading to better support for the design of effective pollution control strategies.