Auroras after CMEs

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Fortunas
Asternaut
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Joined: Sun Aug 11, 2024 5:03 pm

Auroras after CMEs

Post by Fortunas » Sun Aug 11, 2024 5:43 pm

Hi everyone! I have the following questions
1. What does the aurora look like in the sky when SME hits the Earth: does an aurora come from a single point in the sky (or a limited sector), or is the aurora distributed throughout the sky?
2. Have there been cases where, after a CME hit Earth, the auroral rays emanated from one point in the sky, far from the great circles of the North or South magnetic poles?
Thank you for answer.

pitterson
Asternaut
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Joined: Fri Aug 23, 2024 6:39 am

Re: Auroras after CMEs

Post by pitterson » Sun Aug 25, 2024 8:40 am

Fortunas wrote: Sun Aug 11, 2024 5:43 pm Hi everyone! I have the following questions
1. What does the aurora look like in the sky when SME hits the Earth: does an aurora come from a single point in the sky (or a limited sector), or is the aurora distributed throughout the sky?
2. Have there been cases where, after a CME hit Earth, the auroral rays emanated from one point in the sky, far from the great circles of the North or South magnetic poles?
Thank you for answer.
Hi! Auroras typically spread across large areas of the sky, not just from a single point. When a CME hits Earth, the auroras usually appear more concentrated near the polar regions but can expand to lower latitudes depending on the intensity. There have been instances where intense solar activity caused auroras to be visible far from the poles.

Fortunas
Asternaut
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Joined: Sun Aug 11, 2024 5:03 pm

Re: Auroras after CMEs

Post by Fortunas » Sun Aug 25, 2024 11:46 pm

Hi! O.K. When entering the magnetosphere and then the ionosphere, CME particles move along the magnetic field lines. If the aurora occurs at the magnetic poles, the precipitation of particles from practically one point is understandable. However, if the aurora is low-latitude, the particles' precipitation should probably happen along a magnetic arc (along a L-shell), and not from a point. How then to explain the cases when the precipitation of CME particles during low-latitude auroras occurred not along an arc, but practically, as reported by observers, from one central point?

populatewhile
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Re: Auroras after CMEs

Post by populatewhile » Thu Sep 12, 2024 4:36 am

There aren’t documented cases of auroras radiating from points distant from the magnetic poles after a CME, as they are closely tied to Earth's magnetic field.

Fortunas
Asternaut
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Re: Auroras after CMEs

Post by Fortunas » Thu Sep 12, 2024 1:19 pm

For example, on February 4, 1872, the aurora was observed and documented in Bombay and Athens, and on May 15, 1921, on about Samoa. What can this be associated with?

isaachackett
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Re: Auroras after CMEs

Post by isaachackett » Mon Sep 30, 2024 2:42 am

Fortunas wrote: Sun Aug 11, 2024 5:43 pm Hi everyone! I have the following questions
1. What does the aurora look like in the sky when SME hits the Earth: does an aurora come from a single point in the sky (or a limited sector), or is the aurora distributed throughout the sky?
2. Have there been cases where, after a CME hit Earth, the auroral rays emanated from one point in the sky, far from the great circles of the North or South magnetic poles?backyard baseball
Thank you for answer.
The sky is swept with auroras. While auroras often cluster around the poles, their intensity allows them to travel to lower latitudes when a CME is strong enough. Even at regions far from the sun's polar caps, auroras have been observed.
Last edited by isaachackett on Tue Oct 01, 2024 1:11 am, edited 1 time in total.

Fortunas
Asternaut
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Re: Auroras after CMEs

Post by Fortunas » Mon Sep 30, 2024 11:29 am

isaachackett wrote: Mon Sep 30, 2024 2:42 am The sky is swept with auroras. While auroras often cluster around the poles, their intensity allows them to travel to lower latitudes when a CME is strong enough. Even at regions far from the sun's polar caps, auroras have been observed.
Is there a difference between the arrival of a CME and a meteor shower?
Observers often claimed that meteor showers spread radially in different directions from a single centre in the sky. It is known that this is a kind of illusion associated with the effect of perspective. This effect of spreading from a point (centre) is caused by coming from afar, similar to the convergence of railroad tracks from one point. In fact, meteor showers, like railroad tracks, come parallel from a wide radiant. Everything is clear here.
However, why does a similar effect of spreading from one point as a center (in the sky), but far from the magnetic poles, occur when CMEs hit the Earth? After all, CMEs follow geomagnetic force lines and must enter through the magnetic poles.
How does the precipitation of CME’s particles in the atmosphere occur? Can they precipitate from one centre or should, going along the arcs of the lines of force, precipitate only along these arcs?