Auroral Joule heating and its consequences - From global to regional scales

AuroralJoule

Understanding the dynamics of the space environment is a perquisite for providing space weather forecasts to protect vulnerable technological systems. Satellites at low Earth orbit (LEO) experience increased orbital decay during large auroral storms. We'll study auroral heating of the upper atmosphere during geomagnetic storms using state-of-the-art research facilities and analysis methods.

Project information

Project duration

-

Funded by

Research Council of Finland

Project coordinator

University of Oulu

Unit and faculty

Space Physics and Astronomy
Faculty of Science

Contact information

Project leader

Project description

Understanding the dynamics of the space environment is a key task in the solar-terrestrial research. It's also a perquisite for providing space weather forecasts to protect vulnerable technological systems. For example, satellites at low Earth orbit (LEO) experience increased orbital decay during large auroral storms.


In this project we'll study auroral heating of the upper atmosphere, which is due to the Ohmic heating by electrical currents and the impact of energetic particles that create auroral emissions. In addition to global observation networks, we'll utilize two new research infrastructures being build in Lapland: the EISCAT_3D radar system measures the ionized plasma in the upper atmosphere, while a network of Scanning Doppler Imagers (SDI-3D) detects the motion of the neutral gas. These two new facilities, together with existing ground-based instruments and frequent overpasses by research satellites makes northern Fennoscandia the best place in the world to study aurora.


For a related project dealing with space weather effects on LEO satellites, see the JOIN project funded by the European Space Agency.


Project personnel
+ Dr Heikki Vanhamäki (project leader)
+ Dr Marcus Pedersen
+ Dr Habtamu Tesfaw
+ MSc Otso Suomalainen
+ Dr Shin-ichiro Oyama (visiting scientist, Nagoya University)


Project results

[1]: Kärhä O., E. Tanskanen, H. Vanhamäki: Large regional variability in geomagnetic storm effects in the auroral zone. Scientific Reports, https://doi.org/10.1038/s41598-023-46352-0, 2023.

[2]: Juusola L., A. Viljanen, N. Partamies, H. Vanhamäki, M. Kellinsalmi, and S. Walker: Three principal components describe the spatiotemporal development of meso-scale ionospheric equivalent currents around substorm onsets. Ann. Geophys., https://doi.org/10.5194/angeo-41-483-2023, 2023.

[3]: Pitkänen T., G.S. Chong, M. Hamrin, A. Kullen, H. Vanhamäki, J.-S. Park, M. Nowada, A. Schillings, E. Krämer: Fast earthward convection in the magnetotail and nonzero IMF By: MMS statistics. J. Geophys. Res., https://doi.org/10.1029/2023JA031593, 2023.

[4]: Wang X., L. Cai, A. Aikio, H. Vanhamäki, I. Virtanen, Y. Zhang, B. Luo, and S. Liu: Ionospheric conductances due to electron and ion precipitations: A comparison between EISCAT and DMSP estimates. J. Geophys. Res., https://doi.org/10.1029/2023JA032354, 2024.

[5]: Oyama S., H. Vanhamäki, L. Cai, A. Shinbori, K. Hosokawa, T. Sakanoi, K. Shiokawa, A. Aikio, I. Virtanen, N. Nishitani, Y. Ogawa, Y. Miyoshi, S. Kurita: Thermospheric wind response to March 2023 storm: Largest wind ever observed with a Fabry-Perot interferometer in Tromsø, Norway since 2009. Space Weather, http://doi.org/10.1029/2023SW003728, 2024.

[6]: Laitinen J., L. Holappa and H. Vanhamäki: A Combined effect of the Earth's magnetic dipole tilt and IMF By in controlling auroral electron precipitation. J. Geophys. Res., https://doi.org/10.1029/2023JA032040, 2024.

[7]: Madelaire M., K. Laundal, S. Hatch, H. Vanhamäki, J. Reistad, A. Ohma, V. Merkin, D. Lin: Estimating the Ionospheric Induction Electric Field using Ground Magnetometers. Geophys. Res. Lett., https://doi.org/10.1029/2023GL105443, 2024.

[8]: Hatch S.M., H. Vanhamäki, K.M. Laundal, J.P. Reistad, J. Burchill, L. Lomidze, D. Knudsen, M. Madelaire, and H. Tesfaw: Does high-latitude ionospheric electrodynamics exhibit hemispheric mirror symmetry? Ann. Geophys., https://doi.org/10.5194/angeo-42-229-2024, 2024.

[9]: Cai L., A. Aikio, S. Oyama, N. Ivchenko, H. Vanhamäki, I. Virtanen, S. Buchert, M. L. Mekuriaw, and Y. Zhang: Effect of polar cap patches on the high-latitude upper thermospheric winds. J. Geophys. Res., http://dx.doi.org/10.1029/2024JA032819, 2024.

[10]: Reistad J.P., S.M. Hatch, K.M. Laundal, K. Oksavik, M. Zettergren, H. Vanhamäki, and I. Virtanen: Volumetric reconstruction of ionospheric electric currents from tri-static incoherent scatter radar measurements. J. Geophys. Res., https://doi.org/10.1029/2024JA032744, 2024.

[11]: Laitinen J., L. Holappa and H. Vanhamäki: The polarity of IMF By strongly modulates particle precipitation during high-speed streams. Geophys. Res. Lett., http://dx.doi.org/10.1029/2024GL110877, 2024.

[12]: Ellahouny N.M., A. Aikio, H. Vanhamäki, I. Virtanen, L. Cai, A. Marchaudon, P.-L. Blelly, A. Coster, J. Norberg, A. Maute, S.-I. Oyama: EISCAT observations of depleted high-latitude F-region during an HSS/SIR-driven magnetic storm. J. Geophys. Res., https://doi.org/10.1029/2024JA032910, 2024.

[13]: Pedersen M. N., L. Juusola, H. Vanhamäki, A. T. Aikio, A. Viljanen: ``Rapid geomagnetic variations during HSS/SIR, ICME sheath and magnetic cloud-driven geomagnetic storms''. J. Geophys. Res., https://doi.org/10.1029/2024JA032656, 2024.

[14]: Geethakumari G.P., A. T. Aikio, L. Cai, H. Vanhamäki, I. I. Virtanen, A. Coster, A. Marchaudon, P.-L. Blelly, A. Maute, J. Norberg, S. Oyama, Y. Zhang, and B. S. R. Kunduri: ``Total electron content variations during an HSS/SIR-driven geomagnetic storm at high and mid latitudes''. J. Geophys. Res., https://doi.org/10.1029/2024JA033192, 2024.

[15]: Juusola L., H. Vanhamäki, E. Marshalko, M. Kruglyakov and A. Viljanen: ``Estimation of the 3-D geoelectric field at the Earth's surface using Spherical Elementary Current Systems''. Ann. Geophys., https://doi.org/10.5194/angeo-43-271-2025, 2025.

[16]: Oyama S., I.I. Virtanen, H.W. Tesfaw, T. Raita, L. Holappa, Y. Miyoshi, L. Cai, H. Vanhamäki, A.T. Aikio, Y. Ogawa, and K. Hosokawa: ``Geomagnetic activity dependence of the auroral electron precipitation spectrum at high latitudes''. J. Geophys. Res., https://doi.org/10.1029/2024JA033441, 2025.

[17]: Tesfaw H., H. Vanhamäki, I. Virtanen, S. Hatch, M. Zettergren, K. Laundal: ``Modelling regional electric field using EISCAT3D observations''. J. Geophys. Res., https://doi.org/10.1029/2024JA033625, 2025.

[18]: Juusola L., I. Virtanen, S.M. Hatch, H. Vanhamäki, M. Grandin, N. Partamies, U. Ganse, I. Honkonen, A. Workayehu, A. Kero, and M. Palmroth: ``An empirical model of high-latitude ionospheric conductances based on EISCAT observations''. Ann. Geophys., https://doi.org/10.5194/angeo-43-755-2025, 2025.

[19]: Mekuriaw M.L., A.T. Aikio, L. Cai, H. Vanhamäki, I.I. Virtanen, S. Buchert, N. Ivchenko, W. Miloch, Y. Jin, D. Knudsen, and J.K. Burchill: ``Comparison of F–region ion velocities measured by Swarm satellites and EISCAT radars''. J. Geophys. Res., https://doi.org/10.1029/2025JA034422, 2025.

[20]: Manninen J., H. Vanhamäki, A. Aikio and J. Gjerloev: ``Statistical Modeling and Prediction of Ionospheric Equivalent Currents Based on SuperMAG Data''. J. Geophys. Res., https://doi.org/10.1029/2025JA034125, 2025.

[21]: Laundal K.M. , A.S. Skeidsvoll, S. Hatch, B. Popescu Braileanu, M. Madelaire, F.T. Kebede, N. Olsen, H. Vanhamäki: ``Global Inductive Magnetosphere-Ionosphere-Thermosphere Coupling''. Ann. Geophys., https://doi.org/10.5194/angeo-43-803-2025, 2025.

[22]: Laitinen J., L. Holappa, H. Vanhamäki, and S. Milan: ``Timescales of Asymmetries in Magnetospheric Dynamics Induced by the IMF By component''. J. Geophys. Res., https://doi.org/10.1029/2025JA034401, 2025.

[23]: Geethakumari G.P., A.T. Aikio, L. Cai, H. Vanhamäki, I.I. Virtanen, A. Coster, A. Maute, A. Marchaudon and P.-L. Blelly: ``Role of Large-Scale Traveling Ionospheric Disturbances in the Positive Storm Phase Observed by the Millstone Hill Radar and GNSS TEC Measurements''. J. Geophys. Res., https://doi.org/10.1029/2025JA034562, 2026.

[24]: Cai L., A.T. Aikio, G.P. Geethakumari, H. Vanhamäki, I.I. Virtanen, S. Oyama, Y. Zhang, J. Zhang, and M.R. Hairston: ``Ionosphere-Thermosphere Coupling in the Northern Polar Region during the May 2024 Geomagnetic Superstorm''. J. Geophys. Res., https://doi.org/10.1029/2025JA034495, 2026.

[25]: Ellahouny N., A.T. Aikio , I.I. Virtanen, H. Vanhamäki, L. Cai, M.N. Pedersen, and H.W. Tesfaw: ``Statistical characteristics of electron precipitation during HSS- and ICME-driven storms observed by the EISCAT radar''. J. Geophys. Res., https://doi.org/10.1029/2025JA034429, 2026.

[26]: Nair A., L. Holappa, H. Vanhamäki, and S. Milan: ``Evolution of open magnetic flux during substorms: the effects of dipole tilt angle''. Geophys. Res. Lett., https://doi.org/10.1029/2025GL121029, 2026.

[27]: Vanhamäki H., M. Pedersen, A. Aikio, C. Waters, J. Gjerloev, L. Cai, M. Myllymaa, B. Kunduri, K. Sterne, S. Vines, and B. Anderson: ``Joule heating in the northern hemisphere during geomagnetic storms driven by high-speed streams and coronal mass ejections''. J. Geophys. Res., https://doi.org/10.1029/2025JA034968, 2026.

[28]: Oyama S., H. Vanhamäki, L. Cai, K. Hosokawa, T. Sakanoi and K. Shiokawa: ``Dynamics of high-latitude energy conversion on the upper thermosphere based on 9-year measurements from FPI in Tromsø, Norway''. J. Geophys. Res., https://doi.org/10.1029/2026JA035076, 2026.

[29]: Suomalainen O.: ``Evaluation of neutral density in the low Earth orbit using Swarm satellite measurements and TIE-GCM simulations'', Pro-Gradu, university of Oulu, https://urn.fi/URN:NBN:fi:oulu-202606184573, 2026.

Research groups

Ionospheric physics