Researchers have collected in situ ultraviolet (UV) measurements in the upper troposphere, lower stratosphere, and middle stratosphere of Earth using a meteorological balloon equipped with environmental sensors. The measurements will be used to better understand the survivability of microorganisms in these regions of Earth’s atmosphere, where cells are exposed to high amounts of biocidal UV light.

Up until now, scientists studying the relationship between UV and microorganisms in the atmosphere have mostly relied on data generated by models. Direct measurements of UV provide further data that can be used in such studies, and a deeper understanding of the accuracy of data generated by models. The balloon was launched from Illinois, USA, in October of 2018, and measurements were largely consistent with those predicted by models of Earth’s troposphere.

The study, “Ultraviolet light measurements (280–400 nm) acquired from stratospheric balloon flight to assess influence on bioaerosols,” was published in the journal Aerobiologia. This research was supported by the NASA Astrobiology Program and a grant from NASA Planetary Protection.