Context
A recent study by the Indian Institute of Astrophysics (IIA), based on more than a century of observations from the Kodaikanal Solar Observatory, has examined the behaviour of solar supergranulations across different phases of the solar cycle.
About Solar Cycle
- The solar cycle is a recurring pattern of solar activity lasting about 11 years, driven by changes in the Sun’s magnetic field.
- The cycle is commonly tracked through the number and intensity of sunspots visible on the Sun’s surface.
- During the cycle, the Sun’s magnetic poles reverse, causing the north and south poles to switch places.
- Variations in the magnetic field influence solar phenomena such as sunspots and other forms of surface activity.
Stages of the Solar Cycle
- Solar Minimum: The phase when solar activity and sunspot numbers are at their lowest.
- As the cycle progresses, solar activity gradually increases along with the number of sunspots.
- Solar Maximum: The phase of peak solar activity marked by the maximum number of sunspots.
- After reaching its peak, solar activity declines and returns to a new solar minimum, marking the beginning of the next cycle.
Impact on Earth
Variations in solar activity can influence Earth’s environment through changes in solar radiation, cosmic ray flux, and ozone distribution.
Sun’s Supergranulation
- Supergranulation refers to a large-scale cellular pattern observed on the surface of the quiet Sun.
- These structures typically extend over a horizontal distance of about 30,000 km and have an average lifespan of nearly 1.8 days.
- They were first discovered by Hart (1954) using Doppler observations of the Sun.
- The study of supergranulations provides insights into solar surface dynamics and magnetic activity.
