Kodaikanal Solar Observatory study on Solar Cycle

A study led by astronomers at the Indian Institute of Astrophysics has mapped variations in the Sun’s magnetic activity across different latitudes using 11 years (2015–2025) of calcium K-line spectroscopic observations from the Kodaikanal Solar Observatory.

• The observatory, which recently celebrated its 125th anniversary, provided long-term solar data that enabled researchers to develop a new technique for tracking the latitudinal distribution of solar magnetic activity.
• The study identified that concentrations of solar activity closely coincide with the locations where sunspot activity peaks occur during the solar cycle.
• The findings are expected to improve understanding of the solar magnetic dynamo, the mechanism responsible for generating and sustaining the Sun’s magnetic field.
• Better knowledge of solar magnetic activity can enhance predictions of space weather, which affects satellite operations, navigation systems, radio communications, and power grids on Earth.

About the Solar Cycle

• The Sun is a magnetically active star that undergoes a regular 11-year solar cycle.
• During this cycle, the Sun’s magnetic field reverses, causing its north and south magnetic poles to switch places approximately every 11 years.
• The cycle begins with a solar minimum, when the number of sunspots is at its lowest, and progresses to a solar maximum, when sunspot activity reaches its peak.
• Sunspots are temporary dark regions on the Sun’s surface created by intense magnetic activity and serve as an important indicator of the solar cycle.
• Solar maximum is associated with increased occurrences of solar flares and coronal mass ejections (CMEs), which release large amounts of energy and charged particles into space.
• These solar events can trigger auroras, disrupt radio communications and satellite systems, and, in extreme cases, affect electrical power infrastructure on Earth.

Sources: PIB & NASA