Understanding solar flares: How explosions on Sun’s surface can lead to radio blackouts
- July 7, 2023
- Posted by: OptimizeIAS Team
- Category: DPN Topics
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Understanding solar flares: How explosions on Sun’s surface can lead to radio blackouts
Subject :Science and technology
Section: Space technology
Context:
- The Sun emitted an X-class solar flare on July 2, 2023, disrupting radio communications over parts of the United States and the Pacific Ocean, according to media reports.
Details:
- The flare, classified as an X1.0 flare, peaked at 7:14 pm ET.
- X-class denotes the most intense flares, while the number provides more information about its strength.
- A sunspot — a huge dark patch — known as AR3354 appeared on the solar surface and reached its maximum size on June 29, generated a significant M-class flare, and then was calm until July 2, when it unleashed an X-class flare that was directly targeted at Earth.
- Initially, researchers thought the flare might have triggered a coronal mass ejection (CME) — a fast-moving cloud of magnetised plasma.
- A geomagnetic storm, or substantial disturbance of Earth’s magnetic field, would probably result from a CME from a flare of this size striking the planet.
- If a huge geomagnetic storm like the one in 2003 occurred today, it would result in prolonged outages of the electrical power grid, resulting in widespread electrical disruptions, blackouts and devastation.
- The most powerful flare on record was in 2003, during the last solar maximum. It was so powerful that it overloaded the sensors measuring it.
What are solar flares?
- A solar flare is a tremendous explosion on the Sun that happens when energy stored in ‘twisted’ magnetic fields (usually above sunspots) is suddenly released.
- There are five different classes of solar flares: A, B, C, M, and X; each class is at least ten times more potent than the one before it.
- Solar flares are large energy explosions that can affect radio communications, power grids and navigation signals and endanger astronauts and spacecraft.
- They can heat a substance to several millions of degrees in a matter of minutes, producing a burst of radiation that spans the electromagnetic spectrum, from radio waves to x-rays and gamma rays.
- Solar flares cause energy particles to be released into space and directly impact the ionosphere and radio communications at the Earth.
- Therefore, to understand and predict space weather and the effect of solar activity on the Earth, an understanding of both CMEs and flares is required.
Classification of solar flares:
- Solar flares can be divided into various categories based on their brightness in X-ray wavelengths.
- X-class flares are large, significant events that have the power to cause global radio blackouts and persistent radiation storms in the upper atmosphere.
- Medium-sized M-class flares typically result in brief radio blackouts that affect the Earth’s polar regions.
- Sometimes an M-class flare is followed by small radiation storms.
- C-class flares are slight and have little effect on the Earth.
Other important terms:
- Geomagnetic storms: A geomagnetic storm refers to the disruptions to the Earth’s magnetic field caused by solar emissions.
- When a Coronal Mass Ejection (CME) or a high-speed solar stream reaches our planet, it slams into the
- The Earth’s magnetosphere is created by its magnetic fields and it usually protects us from the particles emitted by the Sun.
- Coronal mass ejection (CME): large-scale eruptions of charged particles (plasma) and magnetic fields from the solar atmosphere into space. They can disrupt a range of ground- and space-based technologies and satellites on Earth.
- Solar cycle: The solar cycle, also known as the solar magnetic activity cycle,sunspot cycle, or Schwabe cycle, is a nearly periodic 11-year change in the Sun’s activity measured in terms of variations in the number of observed sunspots on the Sun’s surface.
- Over the period of a solar cycle, levels of solar radiation and ejection of solar material, the number and size of sunspots, solar flares, and coronal loops all exhibit a synchronized fluctuation from a period of minimum activity to a period of a maximum activity back to a period of minimum activity.