University of Oulu

Sinnhuber, M., Nesse Tyssøy, H., Asikainen, T., Bender, S., Funke, B., Hendrickx, K., et al. (2022). Heppa III intercomparison experiment on electron precipitation impacts: 2. Model-measurement intercomparison of nitric oxide (NO) during a geomagnetic storm in April 2010. Journal of Geophysical Research: Space Physics, 127, e2021JA029466.

Heppa III intercomparison experiment on electron precipitation impacts : 2. model-measurement intercomparison of nitric oxide (NO) during a geomagnetic storm in April 2010

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Author: Sinnhuber, M.1; Nesse Tyssøy, H.2; Asikainen, T.3;
Organizations: 1Karlsruhe Institute of Technology, Leopoldshafen, Germany
2Department Physics and Technology, Birkeland Centre for Space Science, University of Bergen, Bergen, Norway
3University of Oulu, Oulu, Finland
4Norwegian University of Science and Technology, Trondheim, Norway
5Instituto de Astrofísica de Andalucía, CSIC, Granada, Spain
6Formerly at the Department of Meteorology, Stockholm University, Stockholm, Sweden
7LASP, University of Colorado, Boulder, CO, USA
8PMOD/WRC, Davos and IAC ETH, Zurich, Switzerland
9Saint Petersburg State University, Saint Petersburg, Russia
10Max-Planck Institute for Meteorologie, Hamburg, Germany
11Institute of Meteorology and Climatology, University of Natural Resources and Life Sciences, Vienna, Austria
12Space and Earth Observation Centre, Finnish Meteorological Institute, Helsinki, Finland
13University of Rostock, Rostock, Germany
14Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow, Russia
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 3.8 MB)
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Language: English
Published: American Geophysical Union, 2021
Publish Date: 2022-01-03


Precipitating auroral and radiation belt electrons are considered to play an important part in the natural forcing of the middle atmosphere with a possible impact on the climate system. Recent studies suggest that this forcing is underestimated in current chemistry-climate models. The HEPPA III intercomparison experiment is a collective effort to address this point.

In this study, we apply electron ionization rates from three data-sets in four chemistry-climate models during a geomagnetically active period in April 2010. Results are evaluated by comparison with observations of nitric oxide (NO) in the mesosphere and lower thermosphere. Differences between the ionization rate data-sets have been assessed in a companion study. In the lower thermosphere, NO densities differ by up to one order of magnitude between models using the same ionization rate data-sets due to differences in the treatment of NO formation, model climatology, and model top height. However, a good agreement in the spatial and temporal variability of NO with observations lends confidence that the electron ionization is represented well above 80 km. In the mesosphere, the averages of model results from all chemistry-climate models differ consistently with the differences in the ionization-rate data-sets, but are within the spread of the observations, so no clear assessment on their comparative validity can be provided. However, observed enhanced amounts of NO in the mid-mesosphere below 70 km suggest a relevant contribution of the high-energy tail of the electron distribution to the hemispheric NO budget during and after the geomagnetic storm on April 6.

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Series: Journal of geophysical research. Space physics
ISSN: 2169-9380
ISSN-E: 2169-9402
ISSN-L: 2169-9380
Volume: 127
Issue: 1
Article number: e2021JA029466
DOI: 10.1029/2021JA029466
Type of Publication: A1 Journal article – refereed
Field of Science: 115 Astronomy and space science
1171 Geosciences
Funding: This paper as well as the companion paper are a collaborative effort of the SPARC SOLARIS-HEPPA initiative ( working group five: Medium Energy Electrons (MEE) Model-Measurement intercomparison. T. Asikainen is supported by the Academy of Finland (PROSPECT project no. 321440). H. Nesse Tyssøy is supported by the Norwegian Research Council (NRC) under contracts 223 252, and 302 040. S. Bender and C. Smith-Johnsen are also supported by the Research Council of Norway contract 223 252. B. Funke acknowledges financial support from the Agencia Estatal de Investigación of the Ministerio de Ciencia, Innovación y Universidades through projects ESP2017-87143-R and PID2019-110689RB-I00, as well as the Centre of Excellence “Severo Ochoa” award to the Instituto de Astrofísica de Andalucía (SEV-2017-0709). Work of E. Rozanov on the input data preparation and experimental setup was supported by the German-Russian cooperation project "H-EPIC" funded by the Russian Foundation for Basic Research (RFBR project 20-55-12020). Work of E. Rozanov and T. Sukhodolov on the analysis of results was performed in the SPbSU Ozone Layer and Upper Atmosphere Research Laboratory, which is supported by the Ministry of Science and Higher Education of the Russian Federation under Grant 075-15-2021-583. Work of T. Sukhodolov on the simulation of the atmospheric state with the chemistry-climate model HAMMONIA and analysis of the results was supported by Russian Science Foundation (project No. 21-17-00208). The work of M. E. Szeląg and P. T. Verronen is supported by the Academy of Finland (project No. 335555 ICT-SUNVAC). J.M. Wissing is supported by the German Aerospace Center (DLR; grant no. D/921/67284894). O. Yakovchuk is supported by the German Science Foundation (DFG; grant no. WI4417/2-10381). The EMAC model experiments were performed on the supercomputer ForHLRII funded by the Ministry of Science, Research, and the Arts Baden-Württemberg and by the Federal Ministry of Education and Research. M. Sinnhuber, B. Funke, J. M. Wissing, and P. T. Verronen would like to thank the International Space Science Institute, Bern, Switzerland for supporting the project "Quantifying Hemispheric Differences in Particle Forcing Effects on Stratospheric Ozone" (Leader: D. R. Marsh).
Copyright information: © 2021 The Authors. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.