Understanding Our Sun's Atmosphere & Its Layers

Hello, Everyone!

In the last post, we understood how our sun is made up of different zones, and every zone has its unique characteristics. Similarly, the Sun's atmosphere is an integration of diverse layers namely the photosphere, the chromosphere, and the corona. These layers are amazingly unique in their properties.

Let us understand these one by one.

-> 1. THE PHOTOSPHERE: this is the bottom-most layer of our sun's environment. This layer makes up the sun's surface which our eyes can perceive. The majority of the energy released is emitted from the photosphere in the form of sunlight. The sunlight takes 8 mins to reach the surface of our Earth. This layer is somewhat less hot as compared to the core of our sun. The photosphere surface has a temperature of 4,125 degrees Celsius. {As per NASA}. However, at the bottom of this layer, the temperature is 6,125 degrees Celsius. {As per NASA}. According to NASA the width of this layer is 300 miles{500 kms}-i.e. from the bottom of the photosphere to the top surface of the photosphere its width is as mentioned. The Hydrogen and Helium are the two gases the Photosphere is composed of.

It is identified by the granules of the hot plasma-{ionized gas}, cooler sunspots- regions of high magnetic phenomenon on the surface of our sun. But why do sunspots seem dark? This is due to their lower temperature than the nearby areas of the sun. Scientists observe the rotation of the sun on its axis by analyzing these sunspots. The sunspots observed at the equator will move from east to west, with the sun's rotation on its axis.

The sun's rotation is not uniform, but it is differential, implying that it rotates differently in different regions. It is due to the gaseous nature of the Sun which possesses liquidy characteristics i.e. it is majorly composed of gases.

The outer layers of the sun's surface near the equator experience less gravitational pull due to the lower density of the gases here than the interior layer which is comparatively much denser at the poles so the equatorial areas complete one rotation at 24 hrs. However, the polar regions complete one rotation at 30 hrs.

2. THE CHROMOSPHERE: It is an extremely hot layer above the photosphere. According to NASA, the temperatures in this layer may vary from 6,000 degrees Celsius to 20,000 degrees Celsius.

This layer emanates a reddish hue when the extremely hot hydrogen combusts off. The reddish surface is visible during a total solar eclipse. However, on normal days the light emanating from the chromosphere is hardly seen since it is less bright than the brighter photosphere.

This layer plays a pivotal role in heat transfer from the core to the exterior of the sun i.e. the Corona. According to scientists, the sunquakes-sun's seismic waves or heat currents have been observed to be traversing from the core to the outermost layer, including the chromosphere. Through the study of these sunquakes, scientists can reveal some fascinating facts about the process by which the transfer, conversion of heat, and distribution of heat are governed. This encompasses some mechanisms such as solar flares- massive explosions from the sun emanating EM radiation and the coronal mass ejections- huge discharges of magnetic field integrated with the hot plasma from the Sun's Corona into space; that define the characteristics of the Corona.

3. THE CORONA: This is the farthest and the most mysterious layer of our Sun's atmosphere. Owing to its high temperatures - 2 mn degrees Celsius regardless of being the outmost layer, this layer is a matter of enigma and research for the scientists. According to the scientists's theory, this extreme heat may be due to the phenomena called nanoflares. The nanoflares are the small explosions in the Sun's atmosphere -much smaller than the solar flares. According to NASA, the nanoflares are 1/1000000000 th of the solar flares size.

Another presumption states that this extreme heat might be due to solar campfires which are minor eruptions or small - solar flares. These were uncovered in the European-U.S. Solar Orbiter mission. These miniature flares resemble the gentle shimmer of a campfire. However, scientists are analyzing these mysterious phenomena, and all these tiny flares play a pivotal role in the high temperatures of the corona. Observations of this enigmatic phenomenon could reveal their effects on the high temperatures of the corona and their influence on the cosmic weather.

Sun's atmosphere is an integration of diverse layers namely the photosphere, the chromosphere, the transition region, and the corona. These layers are amazingly unique in their properties.

Pic Source:https://socratic.org/questions/what-is-the-sun-s-atmosphere-called

Conclusively, we can say that the Sun's atmosphere plays a pivotal role in life on Earth.

REFERENCES:

https://www.space.com/17160-sun-atmosphere.html

https://pages.uoregon.edu/soper/Sun/photosphere.html#:~:text=The%20layer%20of%20the%20Sun,of%20hydrogen%20and%20helium%20gas.