Missing driver in the Sun–Earth connection from energetic electron precipitation impacts mesospheric ozone

• Published in: Nature communications 2014-10, Vol.5 (1), p.5197-5197, Article 5197
• Main Authors: Andersson, M. E., Verronen, P. T., Rodger, C. J., Clilverd, M. A., Seppälä, A.
• Format: Article
• Language: English
• Subjects: 704/106/35; 704/445; Humanities and Social Sciences; multidisciplinary; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms6197

Energetic electron precipitation (EEP) from the Earth’s outer radiation belt continuously affects the chemical composition of the polar mesosphere. EEP can contribute to catalytic ozone loss in the mesosphere through ionization and enhanced production of odd hydrogen. However, the long-term mesospheric ozone variability caused by EEP has not been quantified or confirmed to date. Here we show, using observations from three different satellite instruments, that EEP events strongly affect ozone at 60–80 km, leading to extremely large (up to 90%) short-term ozone depletion. This impact is comparable to that of large, but much less frequent, solar proton events. On solar cycle timescales, we find that EEP causes ozone variations of up to 34% at 70–80 km. With such a magnitude, it is reasonable to suspect that EEP could be an important part of solar influence on the atmosphere and climate system. Energetic electron precipitation (EEP) from the Earth's outer radiation belt can lead to ozone loss in the mesosphere, yet long-term variability has not been quantified. Here, the authors present satellite observations and show that on solar cycle timescales EEP causes ozone to vary by up to 34%.