A computer model lets us see how stealth coronal mass ejections form

Scientists, relying on two solar observatories-Solar Terrestrial Observatory (STEREO) and Solar Heliospheric Observatory (SOHO), developed a Computer Model that reproduces the evolution of solar energy ejections. The model demonstrates the way in which slow solar processes can develop into furious magnetic fields on the surface of the sun. The replica shows how the magnetic field lines form in distinct layers of the sun´s atmosphere, stretching and spiralling furiously and finally exploding with great speed into outer space.

This computer simulation can help scientists better understand coronal mass ejections on the sun and its effects on earth.

Coronal Mass Ejection (CME)

This is a solar process in which large amounts of plasma (electrons and protons) are released by the sun´s magnetic fields. These phenomena are associated with drastic changes and instabilities in the coronal magnetic field. They originate in the sun´s most active regions, such as sunspots (reduced areas of solar surface temperature), driven by concentrations of magnetic field fluctuation. During the Solar maximum, the sun may produce three CMEs in a single day, while during a solar minimum; it only produces one to two CME in a week.

Stealth CMEs

Typical coronal mass ejections are massive explosions of plasma that erupt from the sun; while a typical CME is usually accompanied by some kind of burst and flurry of solar energised particle, there is another kind of CME that does not show any kind of warnings and that scientists have named as stealth CMEs. Compared with conventional CMEs, which are ejected from the sun at speeds of 2,900 km/s (1800 miles/s), stealth CMEs travel at speeds ranging from 400-700 km/s (250-435 miles/s). Although at that speed stealth CMEs are not able to cause any major space weather damage, they can still affect earth´s magnetic field.

Computer model of the sun´s magnetic fields

To unveil the origins of the sun´s stealth CMEs, scientists elaborated a computerised model of the sun´s magnetic fields, replicating their passage through its atmosphere.

Scientists took into account the rotation of the sun, which opposed to the earth’s solid rotation, is not consistent, as it rotates faster at the equator than at the poles. Their model showed how the inconsistency of rotation causes the magnetic fields to stretch and expand at varied rates, generating sufficient energy to create stealth CMEs, which then erupt into interstellar space.