From UPSC perspective, the following things are important :
Prelims level : Stable Aurora Arc
Mains level : NA
- Recently, the Indian Astronomical Observatory (IAO) in Ladakh has astounded the world with mesmerizing images of a rare red-colored aurora, known as a Stable Auroral Arc (SAR).
What is Stable Auroral Arc (SAR)?
- Rare Phenomenon: SAR is a unique atmospheric occurrence witnessed during a potent G3-class geomagnetic storm.
- Unconventional Origins: Unlike typical auroras resulting from space borne charged particles colliding with the atmosphere, SAR arcs have a distinct genesis.
- Sign of Energy Flow: SAR arcs signify the transfer of heat energy into the upper atmosphere from Earth’s ring current system, a circular pathway carrying massive electrical currents encircling our planet.
- Geomagnetic Storm Influence: During the recent geomagnetic storm, the ring current was dynamically charged due to prolonged intense geomagnetic activity, leading to the manifestation of SAR arcs.
- Global Impact: This celestial event left its celestial mark across several regions worldwide.
How is it formed?
- Solar Wind Interaction: Aurora formation begins when the sun emits charged particles from its corona, creating solar wind. Upon colliding with Earth’s ionosphere, the mesmerizing aurora takes shape.
- Northern and Southern Counterparts: In the Northern Hemisphere, it’s recognized as the northern lights (aurora borealis), while in the Southern Hemisphere, it’s referred to as the southern lights (aurora australis).
- Magnetic Dance: The varying appearance of auroras in different hemispheres is attributed, in part, to the intricate interplay between the sun’s magnetic field and Earth’s magnetic field.