A new study found that the Coronal Mass Ejections from the Sun between the 2008-2019 period have significantly decreased. Here’s why.
A month ago, NASA revealed that the solar flares are being extremely active as the Sun enters into a new solar cycle. Contrary to that, Indian astronomers have laid out a new study which revealed that the Sun has been quieter between the period of 2008 and 2019 as compared to 1996 to 2007. The Coronal Mass Ejections between the 2008-2019 period from the Sun have significantly decreased in mass, size as well as the internal pressure of explosive phenomena, study by Scientists of Indian Institute of Astrophysics (IIA), Bengaluru found.
Astronomers aimed to explain the expansion behaviour of coronal mass ejections and their interplanetary counterpart (ICMEs) in solar cycles 23 and 24 in a research paper published in Frontiers in Astronomy & Space Science. The magnetic activity on the Sun fluctuates over an almost 11-year period and is divided into three phases: ascending, maximum, and declining, together known as a solar cycle. The 24th solar cycle lasted from 2008 to 2019.
What research have found?
The average radial size of CMEs in recent decades, which means during solar cycle 24 which lasted from 2008 to 2019 has decreased by two-thirds compared to the previous cycle. It was surprising as the reduced ambient pressure means that CMEs were spreading into interplanetary space to a substantially bigger extent, resulting in a larger radial size.
Scientists discovered that in cycle 24, the gas pressure in interplanetary space was just 40 percent of that in cycle 23. Furthermore, the pace at which the Sun lost mass through these episodic ejections in cycle 24 was 15 percent lower than in cycle 23. According to scientists, CMEs must be examined at various distances from the Sun in order to better understand the development of their radial diameters and expansion behaviour.
What are Coronal Mass Ejections?
In simpler terms, coronal mass ejections (CMEs) can be understood as the massive solar particle eruptions due to intense flares from the sun. CMEs fire an abundance of plasma, gases and magnetic fields out into space, often from the Sunspots which are lumps in the Sun’s magnetic field.
As CMEs escape the Sun, they travel at speeds ranging from less than 250 kilometres per second to over 3000 kilometres per second. CMEs can reach Earth in as little as 15-18 hours, which provides very little warning to astronomers and scientists on earth to prepare and warn everyone about it. Fortunately, not all solar storms travel as fast and generally take over a day to reach Earth.