Why in news?
Researchers at the Indian Institute of Technology, Kanpur developed a new three‑dimensional model to predict solar cycles more accurately. By assimilating 30 years of satellite observations of the Sun’s surface magnetic field, the team produced a 3D map of the Sun’s internal magnetic field and improved forecasts of solar activity that affects space weather.
Background
The Sun undergoes an approximately 11‑year cycle driven by its magnetic field, characterised by alternating periods of high and low sunspot activity known as solar maximum and solar minimum. Predicting the timing and intensity of these cycles is crucial because solar flares and coronal mass ejections can disrupt satellite communications, navigation systems and power grids. Traditional models often struggled to estimate the hidden magnetic field inside the Sun. IIT Kanpur’s approach uses a dynamo model that assimilates decades of observational data to reconstruct the solar interior.
The solar cycle explained
- Magnetic flip: Roughly every 11 years, the Sun’s north and south magnetic poles reverse. It then takes another 11 years to return to the original orientation, making a full 22‑year magnetic cycle.
- Sunspots: Dark, cooler regions on the Sun’s surface where magnetic fields are concentrated. The number and intensity of sunspots rise towards solar maximum and decline towards solar minimum.
- Stages: The cycle begins at solar minimum (few sunspots), builds to solar maximum (many sunspots and solar storms), and declines back to minimum.
- Impacts: Variations in solar radiation influence Earth’s climate, auroras and the flux of cosmic rays. Space‑weather events can damage satellites and power infrastructure.
IIT Kanpur’s contribution
- The researchers, led by Soumyadeep Chatterjee and Prof Gopal Hazra, compiled 30 years of magnetic field measurements from satellites to build a comprehensive data set.
- Using a 3D dynamo model, they mapped the Sun’s internal magnetic field and tracked how large‑scale patterns evolve over time.
- The model has been validated using measurements of the solar polar magnetic field and is expected to improve predictions of the peak and strength of future solar cycles.
- Better forecasts will aid long‑term planning for satellites and power grids and contribute to our understanding of the solar dynamo.
Source: TH
