Antti Kero, SGO, Finland

Jia Jia, SGO, Finland

Mick Denton, Boulder, US

Rigel Kivi, FMI, Finland

Pekka Verronen, FMI, Finland

Annika Seppälä, Otago, New Zealand

Ilya Usoskin, Oulu, Finland

Eugene Rozanov, IAC ETHZ, PMOD/WRC, Switzerland

Christine Smith-Johnsen, University of Bergen, Norway

Niilo Kalakoski, Finnish Meteorological Institute, Finland

Kseniia Golubenko, University of Oulu, Finland

Kenneth Nilsen, SGO, Finland

Our team investigates possible direct stratospheric ozone variability caused by space weather events, i.s., solar proton events and the modulated cosmic ray fluxes.

Recently, Denton et al., [2018 a,b] have discovered a statistically detectable direct ozone reduction during the solar proton events by using the balloon-sounding datasets, i.e., at the altitudes of the ozone layer. This effect is highly unexpected by the current models, as the ionisation rates induced by most of the solar protons events are expected to be significant in the upper stratosphere and mesosphere, but insignificant at the altitudes of the ozone balloon soundings.

The influence of Galactic Cosmic Rays on the stratospheric ozone was studied by using SOCOL model in Calisto et al., 2011. A strong loss in the Antarctic polar lower stratosphere with annual mean mixing ratios decreasing by 3 % was reported. However, this effect has not been confirmed by observations to date.

Our team will make an assessment on these effects based on satellite (MLS, GOMOS) and ground based datasets (ozonesonde) and atmospheric models (SIC, WACCM-D, SOCOL), including the crucial role of the polar vortex. Our primary research objective is to find a mechanism by which the ozone layer is reduced by solar proton events. Moreover, we will assess experimentally the importance of the galactic cosmic ray fluxes variations to the stratospheric ozone.

References

Calisto, M., Usoskin, I., Rozanov, E., and Peter, T.: Influence of Galactic Cosmic Rays on atmospheric composition and dynamics, Atmos. Chem. Phys., 11, 4547-4556, https://doi.org/10.5194/acp-11-4547-2011, 2011.

M.H. Denton, R. Kivi, T. Ulich, C.J. Rodger, M.A. Clilverd, R.B. Horne, A.J. Kavanagh, Solar proton events and stratospheric ozone depletion over northern Finland, Journal of Atmospheric and Solar-Terrestrial Physics, Volume 177, 2018a,

Denton, M. H., Kivi, R., Ulich, T., Clilverd, M. A., Rodger, C. J., & von der Gathen, P. (2018b). Northern hemisphere stratospheric ozone depletion caused by solar proton events: The role of the polar vortex. Geophysical Research Letters, 45.https://doi.org/10.1002/2017GL075966