Context
IIA finds a novel way to explore the sun’s secrets by studying solar magnetic fields, using Kodaikanal Tower Tunnel Telescope.
About Kodaikanal Tower Tunnel Telescope
- Established: 1899
- Location: Southern tip of the Palani Hills, Tamil Nadu
- Kodaikanal was selected for its clear skies, low humidity, and minimal fog.
- Owned and Operated by: Indian Institute of Astrophysics (IIA)
- To study the link between solar activity and monsoons.
- Kodaikanal Tower Tunnel Telescope – Consists of a 3-mirror setup.
- Primary Mirror (M1): Tracks the Sun.
- Secondary Mirror (M2): Redirects sunlight downwards.
- Tertiary Mirror (M3): Makes the beam horizontal.
- Recent Research and Discoveries
- Sun’s Magnetic Field Studies
- Active Region Observations: Studied a sunspot with complex features, including multiple umbrae and a penumbra, using simultaneous observations in the Hydrogen-alpha and Calcium II 8662 Å lines.
- Spectral Line Data: Utilized data from multiple spectral lines, particularly the Hydrogen-alpha line at 6562.8 Å, to analyze magnetic field stratification at various solar atmospheric heights.
About Sun’s Magnetic Field
- Convection Zone: The Sun’s magnetic field is generated in the outer layer called the convection zone, characterized by convective motion where hot plasma rises and cooler plasma sinks.
- Dynamo Effect: The convective motion acts as a dynamo, generating and amplifying magnetic fields through differential rotation, turbulence, and other complex interactions.
- Magnetic Flux Ropes: The generated magnetic fields form twisted structures called magnetic flux ropes. These ropes rise through the Sun’s interior and emerge on the surface, creating phenomena like sunspots.
- Dipolar Configuration: The Sun’s magnetic field is mainly dipolar, with magnetic field lines emerging from one pole and reconnecting at the other.
- Poloidal and Toroidal Components: The magnetic field has poloidal (north-south) and toroidal (east-west) components, influenced by differential rotation and convective motion.
- Active Regions: Areas of intense magnetic activity, known as active regions, often coincide with sun spots where magnetic field lines are highly concentrated and twisted.
- Significance:
- Solar Flares: Magnetic reconnection in active regions can cause sudden energy releases, resulting in solar flares that emit intense bursts of radiation.
- Coronal Mass Ejections (CMEs): Large disruptions in the magnetic field can cause CMEs, where vast amounts of solar material are expelled into space, potentially affecting Earth’s magnetosphere and causing geomagnetic storms.
- Space Weather: The Sun’s magnetic field and related phenomena contribute to space weather, impacting satellites, communication systems, and power grids.
- Geomagnetic storms induced by CMEs can disrupt technological infrastructure and pose risks to astronauts.
Source:
TH
Previous Year Question
If a major solar storm (solar flare) reaches the Earth, which of the following are the possible effects on the Earth?
1. GPS and navigation systems could fail.
2. Tsunamis could occur at equatorial regions.
3. Power grids could be damaged.
4. Intense auroras could occur over much of the Earth.
5. Forest fires could take place over much of the planet.
6. Orbits of the satellites could be disturbed.
7. Shortwave radio communication of the aircraft flying over polar regions could be interrupted.
[UPSC Civil Services Exam – 2022 Prelims]
(a) 1, 2, 4 and 5 only
(b) 2, 3, 5, 6 and 7 only
(c) 1, 3, 4, 6 and 7 only
(d) 1, 2, 3, 4, 5, 6 and 7
Answer: (c)
