Sun has developed a ‘coronal hole’ 20 times the size of Earth

Why in news ? Recently , a solar flare has caused a minor shortwave radio blackout over Indian Ocean 

Background:

• A massive dark patch appeared in the southern stretches of the sun's outer atmosphere, also called the corona. Known as coronal holes, these features are much cooler than the surrounding atmosphere.
• Through these coronal holes, high-speed solar winds made of electrically charged particles and magnetic fields gush out into space; the current hole is releasing winds exceeding 1.3 million mph
• Earth has narrowly escaped the incoming wave of a coronal mass injection (CME) cloud and avoided a solar storm event.
• Things become worse when a newly formed  sunspot exploded spewing out an M 3- class solar flare.

Zone of impact of flares  :

• Usually these flares impact the Pacific Ocean and surrounding countries such as Australia, New Zealand , South American countries and Western coast of USA.
• The recent flare was Earth directed and the high radiation has affected the Indian Ocean region.
• South Asian countries including India, Sri Lanka, Bangladesh , China , Japan and South Korea have fallen into its geo effective area.

Effect of flares

• The flare eruption has caused a shortwave radio blackout in the region for a temporary period.
• During the flare , drone pilots , amateur radio operators and aviators would have faced temporary disruption for airline services and ships in the region.
• Eruption has released a CME cloud which will reach the earth in coming days and cause a solar storm event.
• Such solar storms can damage satellites , disrupt mobile network and internet services and in extreme cases can also damage power grids and Earth based sensitive electronics.
• Solar flares are categorised into B, C, M, and X types. While B class solar flares are minor ones, X class flares are the most potent ones.