5. What is a solar storm? Explain. How does it affect the Earth? Discuss.
सौर तूफान क्या है? समझाएं। यह पृथ्वी को कैसे प्रभावित करता है? चर्चा करें।
Solar storms are a variety of eruptions of mass and energy from the solar surface. Flares, prominences, sunspots, coronal mass ejections are the common harbingers of solar activity, as are plages and other related phenomena. These kinds of space weather activities affect earth and normal functioning of humans on earth.
- Solar activity associated with Space Weather can be divided into four main components: solar flares, coronal mass ejections, high-speed solar wind, and solar energetic particles.
- They all involve sudden releases of stored magnetic energy, which accelerates the hot gases near the surface or in the corona of the Sun. Sometimes these particles make it all the way to the Earth and beyond by flowing along the Sun’s magnetic field into interplanetary space.
- The sun goes through periodic variations or cycles of high and low activity that repeat approximately every 11 years. Although cycles as short as 9 years and as long as 14 years have been observed. The solar or sunspot cycle is a useful way to mark the changes in the sun.
- Solar storms can last only a few minutes to several hours but the effects of geomagnetic storms can linger in the Earth’s magnetosphere and atmosphere for days to weeks.
- When the material collides with the Earth’s magnetic field and trapped radiation belts, it can dump particles into our upper atmosphere to cause the Aurora.
- The same ‘charged’ particles can produce their own magnetic fields which can modify the Earth’s magnetic field and affect compass readings. The changing magnetic fields can also ‘induce’ electricity in long pipelines, or produce electrical surges in our power grids leading to brownouts and black outs.
- Modern society depends on a variety of technologies susceptible to the extremes of space weather. Strong electrical currents driven along the Earth’s surface during auroral events disrupt electric power grids and contribute to the corrosion of oil and gas pipelines.
- Changes in the ionosphere during geomagnetic storms interfere with high-frequency radio communications and Global Positioning System (GPS) navigation.
- During polar cap absorption events caused by solar protons, radio communications can be compromised for commercial airliners on transpolar crossing routes.
- Exposure of spacecraft to energetic particles during solar energetic particle events and radiation belt enhancements cause temporary operational anomalies, damage critical electronics, degrade solar arrays, and blind optical systems such as imagers and star trackers.
- Human and robotic explorers across the solar system are also affected by solar activity. Research has shown, in a worst-case scenario, astronauts exposed to solar particle radiation can reach their permissible exposure limits within hours of the onset of an event. Surface-to-orbit and surface-to-surface communications are sensitive to space weather storms.
As society’s reliance on technological systems grows, so does our vulnerability to space weather. The ultimate goal in studying space weather is an ability to foretell events and conditions on the Sun and in near-Earth space that will produce potentially harmful societal and economic effects, and to do this adequately far in advance and with sufficient accuracy to allow preventive or mitigating actions to be taken.