Monday, July 22, 2013

Earth Facing Coronal Hole

We have a very large coronal hole that is directly in an earth facing position. This same coronal hole has rotated around the sun for 3 rotations it has reduced significantly since that last 2 rotations but there is still a likelihood of a solar storm in 2 to 3 days time. This rotation may also have less impact due to the configuration of the magnetic field of the surrounding area.

Full Disc Coronal hole is in the center

A coronal hole is an area where the magnetic lines are open. The open fields allow the material to be
blown off of the surface in solar winds and then that area becomes cooler. Slightly cooler so in the ultraviolet frequency those area are less bright slightly than the surrounding area.  Some people have been worried that there is something wrong with the sun that there is some enormous catastrophic hole in the sun. That is completely misunderstanding what this image is showing. First you have to remember that ultraviolet light images is recording heat not visible light like what we see. Similar to an FLIR which looks at infrared but at the other end of the visible light spectrum.

This closer and brightened image reveals there is no actual hole. 
The word hole is just a industry term.

Now we can look and the magnetic lines and let me say that the lines in these images are not visible lines either they are added by physicist who use computer models and observations to map where they think that are and as you can see in the following 2 images they don't always agree with each other.

From SDO showing the lines all OPEN.

Magnetic fields from GONG and edited by me to include the SDO image.

If you are worried that a Gigantic Chuck of the sun is headed our way you should know that is not true and that region has already rotated past an earth facing position. The weather we received raised the KP index to 4 


  1. Beautiful artists rendering but with all due respect...
    1) a Coronal hole is a hole in the normal chromospheric covering magnetic canopy which restrains and moderates the solar wind. The energy coming from the Sun's photosphere leaves through this hole at a much faster speed than if the magnetic field were intact, thus presenting a peril to Earth if it is directed this way.
    2)The chromosphere is always hotter than the "surface" photosphere also. To try and say that this part of the photosphere is cooler because of a lack of magnetic field lines is not correct. This area is the same temperature as the rest of the photosphere as evidenced in images from NASA SDO of the photosphere.

    3) Ultraviolet, visible light, infrared, they're all the same thing, just energy at different wavelengths. To say that one is heat and therefore not visible is not correct.

    Not trying to be an ass or anything and I rarely would ever correct minor mistakes in a technical post, but come on, responsibility to put out accurate information.

    1. When is a hole not a hole? When the word scares people to run and hide in a bunker because they fear the sun has literally a giant hole through it. When our words don't communicate what we intend, it is time to try to use different words to clarify our intent. The "peril" (a lovely hyperbolic word btw) being a solar storm, since this coronal hole rotated twice already at least that I am aware of we can expect a similar result as the last 2 times. An increase in solar winds, an increase in auroral activity. People want to know "How will this effect me?" I believe we all are more greatly and directly effected by space weather than is known or understood, simply because we never had this data readily available to make correlations to our own state of well being before. Now that we have this data, it's up to us to begin tracking out own data on how it effects us and reporting on it.

      The color variation within the images in AIA 193 and 211 is due to temperature variations as far as I understand but if you have a link that explains it better I would love to learn more. AIA 304 is the Chromosphere and White light Photoshpere are not one of the layers in this composite image. I plan to go into the detail of what each filtered image shows and tells us in a future article.

      The reference to FLIR is because I feel more people will be familiar with it since it is on TV often, and therefore understand the point that what an instrument records is not necessarily what our eyes can see.

      As Bill Nye says "Everyone you meet knows something you don't" So I appreciate all comments and corrections and enjoy the opportunity for all of us to learn together.