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Understanding Earth's magnetic shield 🌍🧲! A research highlights how geomagnetic field variations impact space weather, affecting satellites, power grids, and communication systems. Protecting tech in a space-weather-driven world! 🚀⚡️

#SpaceWeather #GeomagneticField #Geoeffectivity #Geomagneticrisks
https://doi.org/10.1007/s10712-020-09598-1 Figure 1 – Sources of the Geomagnetic Field 🧲🌍 This figure illustrates the primary sources contributing to Earth's magnetic field: (a) Core Field: Shows contour lines of magnetic field intensity at Earth's surface and at the core-mantle boundary. The South Atlantic Anomaly (SAA) appears as a weak field zone, caused by reversed magnetic flux in the core. (b) Lithospheric Field: Depicts the magnetic field from magnetized rocks in the crust, showing geological patterns like magnetic striping near mid-ocean ridges. (c) Ionospheric Currents: Illustrates electric currents (e.g., Solar Quiet (Sq) currents and the equatorial electrojet) in the ionosphere and field-aligned currents (FAC) that link the ionosphere to the magnetosphere. (d) Magnetosphere: Shows how the magnetosphere shields Earth from solar wind, highlighting current systems like the Chapman-Ferraro currents, the ring current, and the magnetotail. Figure 3 – Dipole Moment Decay Over Time 📉🧲 This graph shows the decline in Earth’s dipole moment from 1900 to 2020: The dipole moment has been decreasing at a rate of ~16 nT/year. Around 1980, the decay rate doubled, indicating a period of accelerated magnetic weakening. If the current rate continues, Earth’s dipole could reach zero in less than 2000 years, impacting its ability to shield against solar particles. Figure 4 – South Atlantic Anomaly (SAA) Intensity Map 🌎💥 This map displays Earth’s surface magnetic field intensity using the IGRF-13 model (2020.5 epoch): The South Atlantic Anomaly (SAA) is shown as a low-intensity region over South America, where the magnetic field is about 1/3 weaker than surrounding areas. The weakened field allows high-energy particles to penetrate deeper into the atmosphere, increasing risks to satellites and technology in orbit. Figure 7 – Quiet vs. Disturbed Day Magnetograms 📊⚡ This figure compares magnetic field variations on two different days using data from Chambon la Forêt Observatory: August 3, 2019 (left) – A quiet day with relatively smooth variations. August 5, 2019 (right) – A disturbed day with more fluctuations and irregular variations. Key Concepts in the Image Magnetograms: These are plots showing variations in Earth's magnetic field over time. The three graphs on each side represent different components of the magnetic field. Magnetic Field Components: X-component (top graph): Represents the northward magnetic field. Y-component (middle graph): Represents the eastward magnetic field. Z-component (bottom graph): Represents the vertical magnetic field. Comparing Quiet and Disturbed Days: Quiet Day (Aug 3, 2019): The variations are smooth and gradual, indicating a stable geomagnetic environment. Disturbed Day (Aug 5, 2019): There are sharp fluctuations, spikes, and irregularities, likely due to geomagnetic activity, such as solar storms. Red Arrows: These arrows represent 20 nT (nanoteslas), providing a reference for scale comparison. They help visually compare the magnitude of variations between the two days. Why is this Important? Understanding magnetograms is crucial for: Space Weather Monitoring: Sharp fluctuations indicate geomagnetic storms, which can be caused by solar activity (e.g., coronal mass ejections). Satellite Protection: Strong geomagnetic disturbances can affect satellites, GPS signals, and radio communications. Power Grid Safety: Severe geomagnetic storms can induce currents in power lines, leading to transformer damage and power outages. Earth's Geomagnetic Studies: Monitoring daily variations helps scientists study Earth's magnetic environment and its interactions with solar activity. Why Use 20 nT as a Measurement? Nanoteslas (nT) are commonly used in geomagnetic research because Earth's magnetic field typically ranges between 25,000 to 65,000 nT.
February 23, 2025 at 1:50 AM