Sun is Loosing its Shine | UPSC
Cold comfort: The sun is cooling.
WHY IN NEWS:
Does it mean there’ll be no global warming ?
SYLLABUS COVERED: GS 3 : Science and Technology
For PRELIMS go through important definitions of Grand solar minimum , solar irradiance etc.
For MAINS can you describe Sun’s atmosphere with a neat diagram . This article will help you with it . Let us dive in !
United States National Oceanic and Atmospheric Administration’s (NOAA) Space Environment Centre.
MODERN GRAND SOLAR MINIMUM
- The last time such an event occurred led to the Little Ice Age
- A new 11-year-cycle of the Sun has begun.
- This year 2020 marks the beginning of the 25th cycle.
- The odd thing is that solar activity, measured by the number of Sun spots at any given time, is pretty low even in 2020.
- 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.
- 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
- 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.
- Some scientists also predict that the solar minimum cooling might cause a Little Ice Age and offset the rising temperatures due to global warming.
- It said even during a Grand Solar Minimum, the decrease in climate forcing would only be worth as much as three years of carbon dioxide growth in the atmosphere.
- NASA also said the impact of global warming would be six times greater than the cooling caused by the Grand Solar Minimum.