Impact of very short-lived halogens on stratospheric ozone abundance and UV radiation in a geo-engineered atmosphere
The impact of very short-lived (VSL) halogenated source species on\nthe ozone layer and surface erythemal ultraviolet radiation (UVERY)\nis investigated in the context of geo-engineering of climate by stratospheric\nsulfur injection. For a projected 2040 model atmosphere, consideration\nof VSL halogens at their upper limit results in lower ozone columns\nand higher UVERY due to geo-engineering for nearly all seasons and\nlatitudes, with UVERY rising by 12% and 6% in southern and northern\nhigh latitudes, respectively. When VSL halogen sources are neglected,\nfuture UVERY increases due to declines in ozone column are nearly\nbalanced by reductions of UVERY due to scattering by the higher stratospheric\naerosol burden in mid-latitudes. Consideration of VSL sources at\ntheir upper limit tips the balance, resulting in annual average increases\nin UVERY of up to 5% in mid and high latitudes. Therefore, VSL halogens\nshould be considered in models that assess the impact of stratospheric\nsulfur injections on the ozone layer.