Spectroscopy measurements show that the absorbance of dust in the far-infrared up to 25 μm is comparable in intensity to that in the mid-infrared (3–15μm) suggesting its relevance for dust direct radiative effect. Data evidence different absorption signatures for high and low/mid latitude dust, due to differences in mineralogical composition. These differences could be used to characterise the mineralogy and differentiate the origin of airborne dust based on infrared remote sensing observations.

In October 2022, we detected volcanic particles in the stratosphere over France, linked to the January 2022 Hunga eruption in the South Pacific. Found between 17 and 23 km altitude, they were traced back to the tropics using trajectory simulations and satellite data. Their optical properties matched those in the Southern Hemisphere. The particles spread across the Northern Hemisphere, reflecting sunlight and slightly cooling the surface—a small but non-negligible effect.

We analyzed the stratospheric aerosol plume from the 2022 Hunga eruption using satellite lidar data. We implemented a method to retrieve some aerosol properties, as standard products failed in this case. We found very high optical depth values in the days following the eruption, which decreased rapidly but remained elevated for months. Our results are broadly validated, though some satellite products underestimate the values due, in part, to the unusual aerosol size distribution in the plume.

The Hunga Tonga–Hunga Ha’apai volcano erupted on 15 January 2022, producing the largest stratospheric aerosol perturbation of the last 30 years. Stratospheric volcanic aerosols usually produce a transient climate cooling; these impacts depend on volcanic aerosol composition/size, due to size-dependent interactions with solar/terrestrial radiation. We demonstrate that the Hunga Tonga–Hunga Ha’apai stratospheric aerosols have a larger cooling potential per unit mass than the past climate-relevant El Chichón (1984) and Pinatubo (1991) eruptions.

The 2019–2020 Australian wildfires triggered massive Pyro-cumulonimbus clouds, injecting smoke aerosols into the stratosphere and forming a self-sustaining vortex that reached 35 km altitude. This vortex created a transient ozone mini-hole. Using satellite and ground-based observations, we tracked a 30–40 % initial ozone depletion, which decayed to ~7 % within a month. These findings highlight the impact of extreme wildfires on stratospheric dynamics and ozone composition.