Impact of the 2021 La Palma volcanic eruption on air quality: Insights from a multidisciplinary approach.

The La Palma 2021 volcanic eruption was the first subaerial eruption in a 50-year period in the Canary Islands (Spain), emitting ~1.8 Tg of sulphur dioxide (SO) into the troposphere over nearly 3 months (19 September-13 December 2021), exceeding the total anthropogenic SO emitted from the 27 European Union countries in 2019. We conducted a comprehensive evaluation of the impact of the 2021 volcanic eruption on air quality (SO, PM and PM concentrations) utilising a multidisciplinary approach, combining ground and satellite-based measurements with height-resolved aerosol and meteorological information.

Radiative habitable zones in martian polar environments.

The biologically damaging solar ultraviolet (UV) radiation (quantified by the DNA-weighted dose) reaches the martian surface in extremely high levels. Searching for potentially habitable UV-protected environments on Mars, we considered the polar ice caps that consist of a seasonally varying CO2 ice cover and a permanent H2O ice layer. It was found that, though the CO2 ice is insufficient by itself to screen the UV radiation, at approximately 1 m depth within the perennial H2O ice the DNA-weighted dose is reduced to terrestrial levels.

Coupling of climate change and biotic UV exposure through changing snow-ice covers in terrestrial habitats.

During the spring, when ozone depletion at the polar regions is at its maximum and consequently the environmental UV exposure is potentially high, many terrestrial communities are covered in snow and heterogeneous snow-encrusted ice that form near the edges of snowpack. Using field measurements and a theoretical radiative transfer model, we calculated the thicknesses of these covers that are necessary to reduce DNA-weighted dose to levels equal to or lower than those received later in the season in the absence of covers when there is no ozone depletion. This depth is approximately 4 cm for a 60% depletion of the ozone column, suggesting that even thin snow-ice covers are enough to completely cancel the biological effects of ozone depletion.