<p>It depends on which region you consider. The lower corona has a plasma number density of the order of <span class="math-container">$10^9 cm^{-3}$</span>, the upper corona about <span class="math-container">$10^5 cm^{-3}$</span>. This is all quite variable though, depending for instance on the solar activity.</p>
<p>Theoretically, the corona is still quite poorly understood, so its physical parameters can generally only be estimated from observations. Various methods have been employed, as for instance described in these papers involving <a href="https://articles.adsabs.harvard.edu//full/1984ApJ...284..412O/0000412.000.html" rel="noreferrer">white light observations</a>, <a href="https://iopscience.iop.org/article/10.3847/1538-4357/ab3e39" rel="noreferrer">ultraviolet light observations</a>, or <a href="https://www.aanda.org/articles/aa/pdf/2015/11/aa25540-14.pdf" rel="noreferrer">radio obervations</a>.</p>

CC BY-SA 4.0
2022-01-06T14:09:25.080Z
Thanks for your answer but I'm interested in knowing that how can one measure these densities? Any mathematical or analytical solution?
Junaid Ihsan
CC BY-SA 4.0
2022-01-06T14:48:00.377Z
@JunaidIhsan Please see my edited answer
Thomas
CC BY-SA 4.0
2022-01-06T23:12:38.950Z
Is this particles per cubic centimetre, or what unit do we have here?
Paŭlo Ebermann
CC BY-SA 4.0
2022-01-07T08:07:59.987Z
@PaŭloEbermann Yes, it is particles per cubic centimetre.
Thomas
CC BY-SA 4.0
2022-01-06T14:03:05.230Z
2022-01-06T14:46:59.417Z
2022-01-06T14:46:59.417Z
Thomas
<p>The Sun's atmosphere, also known as the solar corona, is known to be extremely hot, much hotter than the Sun's surface. What is the plasma density in the solar corona?</p>

<the-sun><stellar-astrophysics><solar-wind><plasma-physics><corona>
Density of Plasma in Solar Corona
Junaid Ihsan
# Density of Plasma in Solar Corona

(Asked by: username_0 on 2022-01-06)

The Sun's atmosphere, also known as the solar corona, is known to be extremely hot, much hotter than the Sun's surface. What is the plasma density in the solar corona?

**Tags:** the-sun, stellar-astrophysics, solar-wind, plasma-physics, corona

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## 1 answers

### Answer by username_1 on 2022-01-06. Score: 7

It depends on which region you consider. The lower corona has a plasma number density of the order of $10^9 cm^{-3}$, the upper corona about $10^5 cm^{-3}$. This is all quite variable though, depending for instance on the solar activity.

Theoretically, the corona is still quite poorly understood, so its physical parameters can generally only be estimated from observations. Various methods have been employed, as for instance described in these papers involving [white light observations](https://articles.adsabs.harvard.edu//full/1984ApJ...284..412O/0000412.000.html), [ultraviolet light observations](https://iopscience.iop.org/article/10.3847/1538-4357/ab3e39), or [radio obervations](https://www.aanda.org/articles/aa/pdf/2015/11/aa25540-14.pdf).

> **Comments:**
> **username_0**: Thanks for your answer but I'm interested in knowing that how can one measure these densities? Any mathematical or analytical solution?  
> **username_1**: @JunaidIhsan Please see my edited answer  
> **username_2**: Is this particles per cubic centimetre, or what unit do we have here?  
> **username_1**: @PaŭloEbermann Yes, it is particles per cubic centimetre.  

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