What is the Difference Between Solar Flare and Coronal Mass Ejection

The key difference between solar flare and coronal mass ejection is that solar flares are very fast, whereas coronal mass ejections are relatively slow.

Solar flares and coronal mass ejections are often related to each other in that a coronal mass ejection typically takes place following a solar flare.

1. Overview and Key Difference
2. What is Solar Flare
3. What is Coronal Mass Ejection
4. Solar Flare vs Coronal Mass Ejection in Tabular Form
5. Summary – Solar Flare vs Coronal Mass Ejection

What is Solar Flare?

Solar flare is the sudden flash of high brightness on the sun that can be observed close to its surface and to a sunspot group. Powerful flares are typically accompanied by coronal mass ejection but not always. Moreover, we can barely detect even the most powerful flares.

Usually, solar flares tend to occur in a power-law spectrum of magnitudes. E.g. an energy release such as 10²⁰ joules of energy can be sufficient in producing a clearly apparent event. But a major event can release up to about 10²⁵ Joules.

Figure 01: Powerful Solar Flares are usually accompanied by Coronal Mass Ejection

Solar Flare Effects

Furthermore, solar flares can affect all the layers of the solar atmosphere. During a solar flare, the plasma medium gets heated to millions of Kelvins. Then, the electrons, protons and heavy ions tend to get accelerated to a speed close to the speed of light. Typically, a solar flare can produce EMR across the electromagnetic spectrum at all possible wavelengths ranging from radio waves to gamma rays. However, most of the energy is spread over the frequencies that are outside the visual range; therefore, we cannot see the majority of the solar. We can use specific instruments for this type of observations. Solar flares appear mainly close to the active regions around the sunspots. These flares are powered by the sudden release of magnetic energy that is stored in the corona.

What is Coronal Mass Ejection?

Coronal mass ejection is the release of a significant amount of plasma and associated magnetic field from the solar corona. Most often, a coronal mass ejection occurs after a solar flare. Normally, this process occurs during a solar prominence eruption. When considering the release of the plasma, it is released into the solar wind. We can observe this process through coronagraphic imaging.

Moreover, we can observe that coronal mass ejection is associated with other forms of solar activity, but most of these relationships are not studied well. The sun generally produces coronal mass ejection every day near the solar maxima. Near the solar minima, this happens only once in five days.

Figure 02: Coronal Mass Ejection

Coronal Mass Ejection Effects

Typically, a coronal mass ejection releases a large quantity of matter and electromagnetic radiation into space above the surface of the sun. This can happen on the sun’s surface, either near the corona, or farther into the planetary system, or even beyond that. When considering this ejecting material, it consists of magnetized plasma and contains primarily electrons and protons. Compared to the speed of a solar flare, coronal mass ejections are slow and develop at the Alfven speed.

What is the Difference Between Solar Flare and Coronal Mass Ejection?

Solar flares and coronal mass ejections are often related to each other in that a coronal mass ejection typically takes place following a solar flare. Solar flare is the sudden flash of high brightness on the sun that can be observed close to its surface and to a sunspot group while coronal mass ejection is the release of a significant amount of plasma and associated magnetic field from the solar corona. The key difference between solar flare and coronal mass ejection is that solar flares are very fast, whereas coronal mass ejections are relatively slow.

The below infographic shows the differences between solar flare and coronal mass ejection in tabular form.

Summary – Solar Flare vs Coronal Mass Ejection

Solar flare is the sudden flash of high brightness on the sun that can be observed close to its surface and to a sunspot group. Coronal mass ejection is the release of a significant amount of plasma and association of magnetic field from the solar corona. The key difference between solar flare and coronal mass ejection is that solar flares are very fast whereas coronal mass ejections are relatively slow.

Reference:

1. “Coronal Mass Ejection.” Wikipedia, Wikimedia Foundation, 29 Apr. 2021.

Image Courtesy:

1. “Magnificent CME Erupts on the Sun – August 31” By NASA Goddard Space Flight Center – Flickr: Magnificent CME Erupts on the Sun – August 31 (CC BY 2.0) via Commons Wikimedia
2. “Coronal Mass Ejection” By the STEREO Science Center – NASA Earth Observatory (Public Domain) via Commons Wikimedia