@article{P_iv_rinta_2013, title={Observed effects of solar proton events and sudden stratospheric warmings on odd nitrogen and ozone in the polar middle atmosphere}, volume={118}, ISSN={2169-8996}, url={http://dx.doi.org/10.1002/jgrd.50486}, DOI={10.1002/jgrd.50486}, number={12}, journal={Journal of Geophysical Research: Atmospheres}, publisher={American Geophysical Union (AGU)}, author={Päivärinta, S.‐M. and Seppälä, A. and Andersson, M. E. and Verronen, P. T. and Thölix, L. and Kyrölä, E.}, year={2013}, month=jun, pages={6837–6848} }