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How can beautiful Auroras disrupt the satellite navigation?

Many people dream of witnessing the Northern Lights, or as they are known scientifically, Aurora Borealis. To watch this natural light show that is put on by an intricate dance of a spectrum of colours is a life changing experience. However, this phenomenon is not a mere dazzling light show. It is a result of a storm of electrically charged particles that are spewed out from the sun, hitting the Earth, interacting with its atmosphere, and creating a beautiful work of art. That’s why, the higher the solar activity, the more pronounced the northern lights would be.


Figure 1: Northern lights over Lapland, Finland. Photo via: Lapin Materiaalipankki | Juha Kauppinen


Having said that, a higher solar activity is also responsible for a series of different disruptions on Earth and can affect almost anything from plants and animals to electric grids and long-range radio and satellite communications.


The sun, although looks calm and composed, is a hot soup that is bubbling with solar activity, but solar activity is a broad term so we need to understand first the different types of solar activities in space so we could relate to their consequences here on Earth:


A solar flare is a sudden burst of electromagnetic energy that carries harmful radiation from the sun and that travels at the speed of light (Gleber, 2014).


CMEs, or coronal mass ejections are triggered by powerful explosions from solar flares that cause billions of tons of hot plasma and particles from the sun to be spilled out (Baker, 2002), and they can have speeds of up to 3500 km/s (Fox, 2012).


Geomagnetic storms occur when a CME hits the Earth, thus instigating thrilling bright auroras and less exciting stuff such as disrupting the Earth’s magnetosphere.


A solar storm is a term that refers to massive energy bursts from the sun in the form of solar flares and CMEs occurrences.



Now that we have defined and understood those terms, let’s move on to their effects on us.


Studies have found out that solar storms can cause a significant short-term depletion of the photosynthesis of certain plants (López-Águila, et al., 2023) and can disrupt animals’ circadian rhythm (Krylov, 2017). Moreover, animals that rely on the Earth’s magnetic field for navigation during migration, such as birds and whales, may become stranded during a geomagnetic storm (Vanselow, et al., 2018).


The effects of solar storms are not considered lethal for us humans or any other living beings, as we are protected by the Earth’s atmosphere that shields us from the harmful radiation. On the other hand, the effects are more striking on our modern infrastructure. You see, electromagnetic variations are insignificant for creatures like us made from flesh and bones but are critical for machines made from metals and wires, which are the building blocks of our technologies. A violent geomagnetic storm can induce current into our power grids which triggers instabilities inside power transmission networks and transformers, causing a total blackout, like what happened in Quebec, Canada in 1989 and in Malmö, Sweden in 2003 (Cannon, et al., 2013).


Now let’s go back to our main question How can beautiful Auroras disrupt the satellite navigation? Briefly, auroras do not directly disturb satellites, but it is a good indication of satellite disruption because the geomagnetic storms that create auroras are responsible for creating satellite disturbances. But how?


The high energy radiation that is emitted by intense solar flares is harmful to satellites orbiting the Earth and can cause severe damage to their sensitive electronics and solar panels causing satellites and their subsystems to fail (Baker, 2002). Solar storms also deposit particles into the ionosphere that increases its density, which in return delays the signals that are coming from satellites towards the Earth (Kumar, et al., 2012). Although the GNSS receivers have models that predict the ionospheric delay, these models are best effective during normal (or average) situations, as ionospheric effects are random effects. When the ionosphere is highly disturbed, the positioning and navigation quality will be severely degraded for a GNSS receiver due to a mismatch between the predicted and the actual delay in the path of the signal transmitted from a GNSS satellite to a GNSS receiver. Moreover, a solar superstorm – i.e., a highly-intense solar storm – can render the GNSS systems inoperable for days (Cannon, et al., 2013). As for low-earth-orbit (LEO) satellites, geomagnetic storms will increase the density of the lower atmosphere causing amplified drag forces on LEO satellites that would slow their velocities and alter their orbits. Drag is a mechanical force that is generated by the interaction and contact of a solid body with a fluid (liquid or gas). Below is a representation of a drag force on a satellite:


Figure 3: Satellite drag. Image via NASA | https://www.swpc.noaa.gov/impacts/satellite-drag


With all that said, should we be worried?


Thankfully, intense solar superstorms that have devastating effects on our infrastructure are not a frequent occasion. These events occur once in a millennia and outer space is so huge that the chance of a burst hitting us is low, and even if a CME does hit us, it must have a magnetic field that is directly opposite to Earth’s magnetic field in order for it to generate major storms (Frazier, 2016). Otherwise, its energy would be deflected by the Earth’s magnetic field towards the north and south poles, creating beautiful auroras. Thankfully, there are scientists that are monitoring the sun so we would know if a CME would hit us hours or even days before it does, and like any other storm, we can prepare for it.


Auroras are a unique manifestation that indicates a CME has struck the Earth. If you were lucky enough to witness them, take a moment to admire how our Earth’s atmosphere can turn a seemingly destructive force into a dazzling spectacle of colours across the night sky.


Majed Imad


References:

Gebler, M. (2014, Sep 21). CME Week: The Difference Between Flares and CMEs. NASA’s Goddard Space Flight Center. https://www.nasa.gov/content/goddard/the-difference-between-flares-and-cmes


Baker, D. N. (2002). Space science. How to cope with space weather. Science (American Association for the Advancement of Science), 297(5586), 1486–1487. https://doi.org/10.1126/science.1074956


Fox, K. (2012, Aug 13). NASA STEREO Observes One of the Fastest CMEs On Record. NASA’s Goddard Space Flight Center. https://www.nasa.gov/mission_pages/stereo/news/fast-cme.html


Byrd. D. (2020, Jan 30). Are solar storms dangerous to us? EarthSky. https://earthsky.org/space/are-solar-storms-dangerous-to-us/


López-Águila, M., Rodríguez-López, L., González-Rodríguez, L., Cardenas, R., & Borges-Márquez, J. (2023). Short-term effects of solar storms in phytoplankton photosynthesis. Astrophysics and Space Science, 368(2), 9–. https://doi.org/10.1007/s10509-023-04162-w


Krylov, V. V. (2017). Biological effects related to geomagnetic activity and possible mechanisms. Bioelectromagnetics, 38(7), 497–510. https://doi.org/10.1002/bem.22062


Vanselow, K. H., Jacobsen, S., Hall, C., & Garthe, S. (2018). Solar storms may trigger sperm whale strandings: explanation approaches for multiple strandings in the North Sea in 2016. International Journal of Astrobiology, 17(4), 336–344. https://doi.org/10.1017/S147355041700026X


Cannon, P., Angling M., Barclay, L., Curry, C., Dyer, C., Edwards, R., Greene, G., Hapgood, M., Horne, R. B., Jackson, D., Mitchell, C. N., Owen, J., Richards, A., Rodgers, C., Ryden, K., Saunders, S., Sweeting, M., Tanner, R., Thomson, A. and Underwood, C. (2013). Extreme space weather: Impacts on engineered systems and infrastructure (pp. 1-68). London, UK: Royal Academy of Engineering. https://raeng.org.uk/media/lz2fs5ql/space_weather_full_report_final.pdf


U.L. Visakh Kumar and P.J. Kurian (2012). Solar Wind: Origin, Properties and Impact on Earth, Exploring the Solar Wind, Dr. Marian Lazar (Ed.), ISBN: 978-953-51-0339-4, InTech, Available from: http://www.intechopen.com/books/exploring-the-solar-wind/solar-wind-origin-properties-and-impact-on-earth


Frazier, S. (2016, Feb 16). NASA Helps Power Grids Weather Geomagnetic Storms. NASA’s Goddard Space Flight Center. https://www.nasa.gov/feature/goddard/2016/nasa-helps-power-grids-weather-geomagnetic-storms

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