University of Oulu

Nilsen, K., Kero, A., Verronen, P. T., Szeląg, M. E., Kalakoski, N., & Jia, J. (2021). Sensitivity of middle atmospheric ozone to solar proton events: A comparison between a climate model and satellites. Journal of Geophysical Research: Atmospheres, 126, e2021JD034549.

Sensitivity of middle atmospheric ozone to solar proton events : a comparison between a climate model and satellites

Saved in:
Author: Nilsen, K.1; Kero, A.1; Verronen, P. T.1,2;
Organizations: 1Sodankylä Geophysical Observatory, University of Oulu, Oulu, Finland
2Space and Earth Observation Centre, Finnish Meteorological Institute, Helsinki, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 1.3 MB)
Persistent link:
Language: English
Published: American Geophysical Union, 2021
Publish Date: 2021-11-12


Energetic particle precipitation (EPP) impact on the middle atmospheric ozone chemistry potentially plays an important role in the connection between space weather and Earth's climate system. A variant of the Whole Atmosphere Community Climate Model (WACCM-D) implements a detailed set of ionospheric D-region chemistry instead of a simple parameterization used in the earlier WACCM versions. This allows WACCM-D to capture the impact of EPP in more detail. Here, we validate the ion chemistry of the WACCM-D by analyzing the middle atmospheric ozone response to the EPP forcing during well-known solar proton events (SPEs). We use a multi-satellite approach to derive the middle atmospheric sensitivity for the SPE forcing as a statistical relation between the solar proton flux and the consequent ozone change. An identical sensitivity analysis is carried out for the WACCM-D model results, enabling one-to-one comparison with the results derived from the satellite observations. Our results show a good agreement in the sensitivity between satellites and the WACCM-D for nighttime conditions. For daytime conditions, we find a good agreement for the satellite data sets that include the largest SPEs (maximum proton flux > 10⁴ pfu). However, for those satellite data-sets with only minor and moderate SPEs, WACCM-D tends to underestimate the sensitivity in daytime conditions. In summary, the WACCM-D with its full ion chemistry and transportation demonstrates a realistic representation of the SPE sensitivity of ozone, and thus provides a conservative platform for long-term EPP impact studies.

see all

Series: Journal of geophysical research. Atmospheres
ISSN: 2169-897X
ISSN-E: 2169-8996
ISSN-L: 2169-897X
Volume: 126
Issue: 18
Article number: e2021JD034549
DOI: 10.1029/2021JD034549
Type of Publication: A1 Journal article – refereed
Field of Science: 115 Astronomy and space science
1172 Environmental sciences
Funding: The work of K. Nilsen and J. Jia is funded by Kvantum Institute through the MEMO project (Mesospheric Monitoring of Ozone Above the Polar Vortex). The work of A. Kero is funded by the Tenure Track Project in Radio Science at Sodankylä Geophysical Observatory/University of Oulu. The work of P. T. Verronen, M. E. Szelag and N. Kalakoski is supported by the Academy of Finland (project No. 335555 ICT-SUNVAC).
Copyright information: © 2021. The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.