Solar spots

 Context: A team of researchers from IISER Kolkata have developed a way of predicting the intensity of activity in the next solar cycle (approximately from 2020 to 2031) using data spread over the last 100 years.

Background:

Astronomers have observed sunspots on the surface of the sun for nearly 400 years. It is known that sunspots follow a cyclic pattern of growing in number and disappearing in approximately 11 years, known as the sunspot cycle or the sun’s activity cycle. We are currently in the 24th sunspot cycle since the observation began in 1755.

Findings:

• The researchers found that the sun’s activity would not dip during the next cycle, but it would be similar to the current cycle, perhaps even stronger. They expect the cycle to peak around 2024.

How was it found?

• The researchers simulated the behaviour of the sun using magnetic field evolution models and observational data. They simulated solar activity, and using inputs from observed data from one cycle, predicted the behaviour of the sun over the next cycle, about ten years in advance.

What are Sunspots?

• Sunspots are temporary phenomena on the Sun’s photosphere that appear as spots darker than the surrounding areas. They are regions of reduced surface temperature caused by concentrations of magnetic field flux that inhibit convection. Sunspots usually appear in pairs of opposite magnetic polarity.

Why study sunspots?

• For the understanding of the long-term variations of the sun and its impact on our climate which is one of the science objectives of Aditya mission. The forecast will be also useful for scientific operational planning of the Aditya mission.
• To know the effects on space weather. This refers to the effect of radiation, particle flux and magnetic flux in the region around the sun. During extreme events, space weather can affect electronics-driven satellite controls, communications systems, air traffic over polar routes and even power grids.
• Sunspots are correlated with climate on earth. A lot of the research in this area focuses on predicting the way the next sunspot cycle will shape up – whether the sun will be extremely active and produce many sunspots or not.

‘Maunder-like minimum’:

• There have been predictions that the next cycle (cycle 25) will show reduced sunspot activity. There have even been speculations that the sun may be heading towards a period of prolonged low activity – what solar physicists describe as a ‘Maunder-like minimum’.
• The Maunder minimum refers to a period from 1645 to 1715 where observers reported minimal Sunspot activity — the number of sunspots reduced by a factor of nearly 1,000, over a period of 28 years.
• During this and other such periods of low activity, some parts of Europe and North America experienced lower-than-average temperatures. While the connection between the Maunder minimum and the climate on earth is still debated, it gives another reason to watch the sunspots.

By: Priyank Kishore