Solar Mean Magnetic Field (SMMF)

1 min read
Prelims: Science & Technology
Solar Mean Magnetic Field (SMMF) Blog Image


Recently, scientists from the Indian Institute of Astrophysics (IIA) through their latest study have given a clearer picture of how the sun’s magnetic field influences the interplanetary magnetic space.

Why in the news?

  • According to the Department of Science and Technology, scientists now are one step closer to identifying the source of the Solar Mean Magnetic Field (SMMF).

About Solar Mean Magnetic Field:

  • It is the mean value of the line-of-sight (LOS) component of the solar vector magnetic field averaged over the visible hemisphere as well as its relationship with Interplanetary Magnetic Field (IMF).
  • The sun contains the corona (the outer shell of the sun’s atmosphere), the photosphere (the visible surface), and the chromosphere (near-transparent layer, just above the photosphere) with the magnetic field generated by electrical currents acting as a magnetic dynamo inside the sun.
  • However, so far, the studies on the SMMF have mostly been confined to the magnetic field measurements at the photosphere.
  • New Findings:
    • Scientists in their quest to understand if and how the SMMF at chromospheric heights is related to the SMMF at photospheric heights have found a very good similarity between the two.
    • The value of chromospheric SMMF is lower than the photospheric SMMF, thereby suggesting that the primordial magnetic field inside the sun could be a source of the SMMF.
    • They calculated and analysed the SMMF using magnetic field measurements at the chromosphere, in conjunction with that of photospheric measurements.
    • These electrical currents are generated by the flow of hot, ionised gases in the sun’s convection zone.


Q) What is Solar flare?
A solar flare is a sudden and intense eruption of energy from the Sun's surface. It is a result of the release of a large amount of magnetic energy in a relatively short period of time. Solar flares are most commonly observed in the vicinity of sunspots, which are regions of intense magnetic activity on the Sun's surface.

Source: Scientists now one step closer to identifying the source of solar mean magnetic field: Indian Institute of Astrophysics study