We refined the traditional isotopic mathematical model, originally predicated on the assumption of exhaustive sulfur dioxide oxidation, to account for the incomplete oxidation processes observed in our field campaigns. By constraining this modified framework with in-situ isotopic data, we demonstrated that conventional models, which overlook this partial oxidation, tend to significantly underestimate sulfate source contributions during the summer.

Current satellite water vapor fusion and calibration methodologies predominantly rely on high-density ground-based station networks, rendering them unsuitable for sparsely monitored regions. This study pioneers the investigation of response relationships between station distribution patterns and satellite water vapor calibration, offering crucial insights for reference station selection in water vapor fusion within sparse monitoring areas.

Carcinogenic nitrosamines are pervasive in air pollution, yet their origins remain elusive. Using Born–Oppenheimer molecular dynamics, we demonstrate that nitrosamines form rapidly at the air–water interface via the reaction of amines with dinitrogen tetroxide. This mechanism also yields nitrous acid, thereby exacerbating pollution. By identifying this critical missing source of airborne carcinogens, our work underscores the necessity of integrating interfacial chemistry into atmospheric models.

Many tiny particles are formed high in the tropical atmosphere, but their impact lower down is unclear. We studied how these particles move downward using long-term computer simulations. We found that particles can reach middle levels of the atmosphere within a week, carried by winds. These results help us understand how pollution and clouds might change as particles spread around the world.

Our manuscript presents a six-year, high-resolution inversion of European methane emissions using the Community Inversion Framework and FLEXPART. Leveraging an expanded in situ network, we reconcile inventories with observations, reveal regional biases, refine European methane budgets, and highlight the dominance of agricultural emissions. Results provide policy-relevant insights for mitigation and inventory verification.

Mineral dust can initiate ice formation in clouds, affecting cloud properties and regional climate. Using an improved model, we examined their contrasting impacts in mixed-phase and ice clouds over East Asia. In mixed-phase clouds, dust promotes liquid-to-ice conversion and reduces cloud reflectivity, causing moderate warming, whereas in ice clouds, it greatly enhances ice formation and leads to stronger warming. This study advances understanding of aerosol–cloud–climate interactions.

Marine atmospheric aerosols remain a major uncertainty in climate models. We report gas and particle phase measurements of two important aerosol forming vapours, sulfuric acid and methanesulfonic acid in the Indo-Pacific. We find that the latter typically dominates over sulfuric acid and contributes significantly to free tropospheric aerosol. Deep convection transports the precursor of both acids to the upper troposphere, providing a key aerosol source in the pristine remote Pacific Ocean.

We studied four major dust events from the Sahara and the Middle East over the Mediterranean. Saharan dust events exhibited coarser and more scattering particles, while Middle Eastern dust was finer and mixed with pollution. Differences in absorption could not be explained by mineralogy and are attributed to mixing.