Our results show that crustal element ratios and clay contents distinguish dust aerosols from arid western coastal areas and humid eastern inland regions in Southern Africa. This dust contains key micronutrients that can become bioaccessible during atmospheric transport to nearby and remote marine ecosystems. It is also enriched in carbonates and K-feldspar, serving as a source of cloud condensation and ice nuclei, with potential implications ranging from regional to sub-hemispheric scales.

This study presents the characteristics and potential origins of nitroaromatics (NACs) in winter PM_2.5 across 11 Chinese cities, along with key factors controlling their formation. We propose that relative humidity- or aerosol liquid water-promoted NAC formation from lab studies may not be universally interpretable in real atmospheres, where multi-factor interactions are critical. This work highlights the need to consider complex field conditions in future research on NAC formation mechanisms.

Worldwide reconstructed historical aerosol load reveals that during the period of:

• 1900–1959: the atmosphere became cleaner in most European cities;
• 1960–1985: anthropogenic aerosols were responsible for the dimming phenomenon in Europe. AOD increased over Southeast Brazil and decreased noticeably over Japan while a small negative trend was found over Oceania;
• 1986–2015: generally, the atmosphere has become much cleaner everywhere after the reversal trend around 1980s mainly observed in Europe.

Heatwaves worsen ozone and secondary organic aerosol pollution. We quantified how much comes from heat speeding up chemical reactions versus increasing natural emissions in China. High temperatures drive over 80 % of the pollution increase nationwide by making the atmosphere more chemically reactive. The effect was strongest in the Yangtze River Delta and Pearl River Delta. Limiting climate change is essential for controlling future pollution and protecting health.