Topic : Important Geophysical phenomena such as earthquakes, Tsunami, Volcanic activity, cyclone etc., geographical features and their location-changes in critical geographical features (including water-bodies and ice-caps) and in flora and fauna and the effects of such changes.
1. What is Magnetic Reconnection with respect to the sun’s surface? Discuss its role in coronal heating and coronal mass ejection. (250 words)
Reference: phys.org , The Hindu
Why the question:
An international team of solar physicists have measured the global magnetic field of the sun’s corona, or outer atmosphere, for the very first time. Thus the question.
Key Demand of the question:
Explain in detail the concept of magnetic Reconnection and its role in coronal heating and coronal mass ejection.
Directive:
Discuss – This is an all-encompassing directive – you have to debate on paper by going through the details of the issues concerned by examining each one of them. You have to give reasons for both for and against arguments.
Structure of the answer:
Introduction:
Define Magnetic reconnection first; Magnetic reconnection is a process where opposite polarity magnetic field lines connect and some of the magnetic energy is converted to heat energy and also kinetic energy which leads to the generation of heating, solar flares, solar jets, etc.
Body:
Explain that Reconnection is at the heart of many spectacular events in our solar system. For example, solar flares which occur near sunspots are believed to be powered by magnetic reconnection. Solar magnetic activity, including flares, can eject high energy charged particles into space. When the particles reach Earth, they can disrupt power grids and communications systems and threaten spacecraft and satellites.
A related phenomenon is the aurora seen near the polar regions of Earth as well as on other magnetized planets. The Earth’s own magnetic field is constantly perturbed by the impinging field from the sun (called the solar wind). During strong bursts (such as those caused by extraordinary solar flares) reconnection can be induced in the near-Earth magneto tail (a narrow magnetic field structure located on the night side many Earth-radii away). The tenuous plasma in that region is then accelerated down magnetic field lines into the Polar Regions, striking Earth’s atmosphere and exciting nitrogen and oxygen atoms as well as other atoms present in our atmosphere. The immediate de-excitation of these atoms then emit the wonderful and often intricate display of light we know as the aurora or northern (and southern) lights.
Discuss its contributions to coronal heating and coronal mass ejection in detail.
Conclusion:
Conclude with importance of such a discovery.
