Between November 9 and 11, several intense solar flares occurred on the sun, including a particularly strong X5.1-class eruption – one of the most energetic in recent years. These flares were accompanied by several coronal mass ejections (CMEs), which are now hitting Earth.
During the night of November 11 to 12, the resulting geomagnetic storm temporarily reached level G4 (“severe”). Experts believe it is possible that the activity could increase to a G5 storm, the highest warning level, in the coming hours. This event is thus once again significantly stronger than the G3 storm we reported on last week.
The NOAA Space Weather Prediction Center and the Ionosphere Monitoring and Prediction Center (IMPC) of the German Aerospace Center (DLR) are continuously monitoring developments. Warnings are being issued about possible disruptions to satellite navigation (e.g., GPS).
If the skies are clear, there will be another chance to observe the Northern Lights in Germany over the coming nights – especially in the northern regions.
Effects on satellite navigation
Satellite signals are affected when they pass through the ionosphere: radio signals are “deflected” by the plasma in the ionosphere. The decisive factor here is the total electron content (TEC) of the ionosphere, i.e., the number of electrons along the signal path. Space weather events can change the TEC very quickly, making this “deflection” of signals difficult to predict and correct.
This is highly relevant for satellite-based navigation, as positioning is determined by the time delay in the arrival of signals from multiple satellites. The “deflection” of the signal and the associated minimal time deviation leads to a slightly inaccurate positioning. This is referred to as a propagation error.
Such errors are extremely dangerous in applications that require high-precision positioning, such as driverless cars. TEC maps based on ionosphere models can be used to detect and correct these deviations.
In addition, space weather can cause so-called ionospheric disturbances, i.e., strong temporal and spatial fluctuations in electron content. These disturbances cause a kind of noise in the satellite signal, which is referred to in technical jargon as “scintillation.” Additional uncertainties or, in the worst case, even complete signal loss are the possible consequences.
Space weather research at DLR
The extensive spectrum of processes involved in space weather is being researched at the DLR Institute of Solar-Terrestrial Physics in Neustrelitz, Mecklenburg-Western Pomerania. Here, the focus ranges from basic research into physical processes to application-oriented concepts for reducing the impact on vulnerable technologies. The goal is to protect national infrastructures and support affected industries through timely, accurate, and reliable observations and predictions.
Further links
• DLR topic page
• Institute of Solar-Terrestrial Physics
• Article in DLR Magazine 177: Frolicking fire foxes light up the heavens!
