Sun is Loosing its Shine | UPSC

• The odd thing is that solar activity, measured by the number of Sun spots at any given time, is pretty low even in 2020.

SUN SPOT

• Sometimes they are large as planets — that appear as darker spots because they are cooler.
• The Sun had no Sun spots for around 71 per cent in 2020 through September 21, 2020, compared to 77 per cent in 2019.
• In May this year, it was as high as 78 per cent, sparking fears of a Little Ice Age.
• Scientists say the Sun may be going through a long period of decreased activity –Modern Grand Solar Minimum from 2020 to 2053.

WHAT IS LITTLE ICE AGE

• The last time such an event occurred was during the Maunder Minimum — from 1645 AD to 1710 AD.
• It was part of what is now known as the Little Ice Age .

• The surface temperatures on Earth will go down noticeably during the Modern Grand Solar Minimum due to a 70 per cent reduction in solar magnetic activity.

SOLAR IRRADIANCE

• The complex magnetic activity in the interior of the Sun and how this impacts its total energy output measured as solar irradiance.

• They also influence the transport of solar energy towards the planet’s surface.
• The magnetic activity through the solar background magnetic field which occurs in the form of two magnetic waves inside the Sun.

SOURCES : NOAA

MAUNDER MINIMUM

• During the Maunder Minimum in the middle ages, the solar irradiance went down by 0.22 per cent or 3 watt per square metre (W/sqm) in 1710 AD when the period ended.

• This also led to frozen rivers, long cold winters and cold summers.
• This happened because of the complex impacts of decreased solar activity on the abundance of ozone in the Earth’s atmosphere and North Atlantic Oscillation (NAO).
• The NAO is the balance between a permanent low-pressure system near Greenland and a permanent high-pressure system to its south, was in a negative phase during the Maunder Minimum.
• This plunged Europe into colder-than usual temperatures.

• In the absence of the shielding more rays reaching the Earth and forming high clouds in the atmosphere, it is leading to the cooling.
• The planet’s temperature might plummet by 1°C during the current grand solar minimum.

WORK IN PROGRESS

• The sun’s activity is not completely understood.
• Scientists takes six months to a year to just decide upon what exactly is happening in the Sun from observations.
• On May 29, a NASA spacecraft observed a family of sunspots that were associated with the biggest solar flare.

• When the flares are big enough or called as solar maximum — they can disrupt satellite communications.