Talk:Ionosphere

Nobel Prize

(William M. Connolley 22:30, 25 Sep 2004 (UTC))

Edward V. Appleton was awarded, by Ernest Rutherford, a Nobel Prize for demonstrating the existence of the ionosphere

Since when did Rutherford get to award Nobel prizes???

That's Ernest Nobel. He changed his name when he became a Knight of Rutherford.

I imagine it was Alfred Nobel that gave money for the Nobel prizes but he did not really award Nobel prizesMkomboti (talk) 05:01, 3 April 2023 (UTC)

contradiction

First line of this article: The ionosphere is the part of the atmosphere that is ionized by solar radiation

And then the last sentence of the first paragraph under 'Geophysics': Note: The ionosphere is NOT a layer in the Earth's atmosphere.

So which one is it?

heh. hmm.. might depend on your definition of edge of space? - Omegatron 15:47, Mar 8, 2005 (UTC)

Actually, no contradiction, however the working can be improved. The ionosphere is PART of the atmosphere, but not a LAYER. The new graphic should also help. Bhamer 06:25, 9 Mar 2005 (UTC)

I note that the first sentence of the article states:

"The ionosphere (play /aɪˈɒnəsfɪər/) is a part of the upper atmosphere, from about 85 km to 600 km altitude,"

but later it says:

"The ionosphere is a shell of electrons and electrically charged atoms and molecules that surrounds the Earth, stretching from a height of about 50 km to more than 1000 km."

and "The D layer is the innermost layer, 60 km to 90 km above the surface of the Earth."

So this article gives three different numbers for the beginning of the ionosphere. I am not an expert, but this is clearly wrong. Perhaps the first line should be "starting at about 50 - 85 km (depending on latitude and time of day) and extending up to about 600 km altitude."

Geomagnetic storm

Maybe "Geomagnetic storm" should be in magnetosphere? (SEWilco 04:21, 16 Mar 2005 (UTC))

Geomagnetic storm is the correct term, but I did change "Earth's magnetic field" to "Earth's magnetosphere". That is more correct. Bhamer 04:56, 16 Mar 2005 (UTC)

Rephrasing: Maybe the section "Geomagnetic storm" should be in the article magnetosphere? However, maybe it actually should be in the article geomagnetic storm. Of course, there should be mention in this article of its effects upon the ionosphere. (SEWilco 08:10, 16 Mar 2005 (UTC))

OK. Probably what needs to be done is have the article geomagnetic storm be expanded to include its effect on the ionosphere, have more details on the types and severity of geomagnetic storms, and also the effects of the storms on landline communications systems and power grids. There is a lot more material to cover on geomagnetic storms and a lot of good examples of its effects on power grids. The storms also effect man-made satellites. Bhamer 11:41, 16 Mar 2005 (UTC)

I stumbled across a source for that. Done. Plenty to update over yonder now. (SEWilco 08:09, 19 Mar 2005 (UTC))

'Would be too interesting to have Aurora Borealis at South Pole'

Ok, I'm slow.. don't understand the above statment. yes, I got lazy, Aurora in southern hemisphere is Aurora Australias. Is this your comment? Bhamer

Looks to me like you understood it. (SEWilco 05:58, 20 Mar 2005 (UTC))

High-frequency (HF)

it influences high-frequency (HF) (3kHz-30MHz) radio propagation

Should that lower limit be 3MHz, not 3kHz? Josh Cherry 02:57, 27 May 2005 (UTC)

Yup. Radio frequency. Fixed. (SEWilco 08:57, 27 May 2005 (UTC))

Height of the E layer

Kile Baker
The entry describing the change in height of the E layer as being due to solar wind "pressing" on the ionosphere is completely wrong. There may have been some confusion between the effects of the solar wind and the effects of the thermosphere neutral wind. Here is a quote from Hargreaves book about sporadic E.

Typical sporadic-E layers are only a few kilometers thick at mid-latitudes. . . . The main cause is thought to be a change in wind speed with height, a wind shear, which in the presence of the geomagnetic field can act to compress the ionization.

Note that the comment refers: (1) to sporadic-E and not the E layer in general, (2) is talking about wind shear in the ionosphere, not the solar wind, and (3) talks about compressing the layer, not "pressing" it downward.

E Layer contradictory statements

First we have this:

"At night the E layer rapidly disappears because the primary source of ionization is no longer present. "

Followed by:

"After sunset an increase in the height of the E layer maximum increases the range to which radio waves can travel by reflection from the layer."

It can't be both ways. Either the E layer disappears at night or it doesn't! — Preceding unsigned comment added by 124.170.204.195 (talk) 09:48, 29 March 2013 (UTC)

There is no "project" in HAARP

I killed the word "project" in "project HAARP." HAARP is a program, not a project. Besides, it sounds pretty silly to talk about "project high-frequency active auroral research PROGRAM," doesn't it? John Elder 09:01, 21 May 2006 (UTC)

ISR

The ISR section really needs to be written in the article. The Arecibo facility is mentioned later in the article; this should be moved into the ISR section. Also, Jicamarca, which is one of the biggest ISRs currently being used to study the ionosphere, is not even mentioned. Is there anyone with more familiarity with these facilities who could write the ISR section?

Tesla

The comment inserted about Nikola Tesla is bogus. Tesla is a fascinating character, but he knew nothing about the ionosphere, and it is highly unlikely that he resonated the Earth with his Colorado Springs experiment. Beware of the crank science that orbits around Tesla's name. DonPMitchell 02:40, 29 July 2007 (UTC)

Very few references

There are only two references in the section "The Ionospheric Layers", neither of which verify the scientific content. For instance, the sentences "Ionization here [the D layer] is due to Lyman series-alpha hydrogen radiation at a wavelength of 121.5 nanometre (nm) ionizing nitric oxide (NO). In addition, when the sun is active with 50 or more sunspots, hard X-rays (wavelength < 1 nm) ionize the air (N2, O2)." have no references, and this is hardly 'common knowledge'. SkunkyMonkey (talk) 19:20, 21 May 2008 (UTC)

Another point refers to the Figure on top of this section: it gives the impression that four layers are clearly separated from each other. This is´nt true for the couple E and D on the one hand and F1 and F2 on the other. If the white space between cannot be erased one should at least give an explanation in the caption. kmarawer Kmarawer (talk) 23:26, 23 January 2010 (UTC). Needs more references.

Ref(ra|le)ction

This article among most others talks about radio waves refracting from the ionosphere. To my understanding what happens is clearly reflection. Refraction would only change the direction slightly, but the waves actually reflect back towards Earth, so in my understanding refraction is not the case! --84.250.188.136 (talk) 22:09, 17 June 2008 (UTC)

Reflection holds only for vertical incidence. At oblique incidence (so for propagation) the ray may in fact be writhed by up to 180 degrees Kmarawer (talk) 17:49, 25 January 2010 (UTC)

If this is true, then atmospheric scientists must use different language than physicists. To physicists, the wave returning back to earth is clearly reflected. There is no refracted wave below the plasma frequency. I have change it. —Preceding unsigned comment added by 129.63.129.170 (talk) 19:04, 9 March 2010 (UTC)

It is easily misunderstood. Except for rare cases, refraction is the correct term. See, for example, the first two paragraphs at Skywave, noting especially the "bent back (refracted), as if reflected" passages. The terms are often used interchangeably. I am reverting most of the edit. Hertz1888 (talk) 20:56, 9 March 2010 (UTC)

Refraction is correct: the ray path penetrates into the ionosphere and is bent through an angle over some distance due to the gradient in the index of refraction. This is not reflection from an interface as it is described in physics. However, since ionospheric refraction of signals below the critical frequency redirects upward rays in a downward direction, people (even those who work in ionospheric radio propagation) do commonly call it reflection, too. So the use of either term is reasonable. — Preceding unsigned comment added by 128.18.41.68 (talk) 15:39, 27 June 2014 (UTC)

Collision Freq in D layer

"frequency of collision between electrons and other particles in this region during the day is about 10 million collisions per second. "

per what? cubic centimeter? —Preceding unsigned comment added by 71.15.154.147 (talk) 08:10, 13 May 2009 (UTC) kmarawer per elctron. It might be better understandable to say:"10 collisions per msec and electron"Kmarawer (talk) 10:03, 16 January 2010 (UTC)

located in the thermosphere

i removed that statement as the ionised section of the atmosphere is not located only in the thermosphere--Mongreilf (talk) 19:23, 24 May 2009 (UTC)

D, E, and F

How did these layers get those particular names? Were there at one time thought to be A, B, and C layers? It would be good if this article answered those questions. Carolina wren (talk) 02:43, 20 April 2011 (UTC)

The E layer was discovered first, and the "E" stood for electric. The rest followed as you might expect. 98.212.193.212 (talk) 05:54, 21 November 2011 (UTC)

Importance of AEROS A and B satellites?

"From 1972 to 1975 NASA launched the AEROS and AEROS B satellites to study the F region."

Why specifically mention these satellite missions? I think this gives the false impression that we no longer have satellites studying the F region. 98.212.193.212 (talk) 05:58, 21 November 2011 (UTC)

Geophysics:thermosphere: short period of time

Please clarify: "...the atmosphere is so thin that free electrons can exist for short periods of time..." Is that like nano seconds? (surely a short period of time) or seconds? DGerman (talk) 19:39, 20 March 2012 (UTC)

Probably worthy of clarification we may be talking about collision frequency at some point. On another note I am not sure what a shell of electrons in the first sentence means Mkomboti (talk) 16:18, 5 April 2023 (UTC)

Thermosphere and ionosphere

What actually is the difference between these two? I think they are the same and ionosphere is the more common term. If so these two articles should be merged. Thoughts? Aarghdvaark (talk) 04:50, 2 May 2012 (UTC)

There are 5 layers of the atmosphere (Troposphere, stratosphere, mesosphere, thermosphere, exosphere). These layers are differentiated based on chemical composition, density, temperature, etc. The ionosphere is that area of the atmosphere that has significant free electron content. Roughly, it spans the mesosphere, thermosphere, and part of the exosphere. It's a separate definition than the atmospheric layers. 130.126.139.230 (talk) 00:20, 9 May 2012 (UTC)

Yes, you are right, but the Wikipedia articles are not so clear about the distinction. e.g. "Radiation causes the atmosphere particles in this layer [the Thermosphere] to become electrically charged (see ionosphere), enabling radio waves to bounce off and be received beyond the horizon" and "Within this layer [the Thermosphere], ultraviolet radiation causes ionization". There is no other mention of the ionosphere in the mesosphere article, except as a 'see also' link. There is no mention at all of the ionosphere in the exosphere article. The mesosphere article does though note that the mesosphere contains the D layer of the ionosphere. Without reading the ionosphere article, the impression would be that all layers of the ionosphere but the D layer are in the thermosphere. Aarghdvaark (talk) 08:59, 9 May 2012 (UTC)

nuclear bombs

Why is it that you do not mention the nuclear bombs that were set off in the ionosphere in the 50's and 60's ? — Preceding unsigned comment added by Arydberg (talk • contribs) 11:31, 29 May 2013 (UTC)

Because no one's written it yet! Be Bold. 130.126.139.230 (talk) 22:45, 16 October 2013 (UTC)

Mechanism of refraction vs. Earth-ionosphere waveguide

The Earth-ionosphere waveguide (EIWG) analysis applies at wavelengths comparable to the vertical distance between the Earth's surface and the lower (gradual) boundary of the ionosphere -- that is, it applies to VLF propagation. Technically speaking, this may be said to be due to refraction, but it is not the straightforward to think of it as the Fresnel type of refraction at a boundary because the wavelength is much larger than the thickness of the gradual boundary. It has more to do with the boundary conditions of Maxwell's equations at electrically lossy interfaces. The EIWG analysis does not apply at much shorter wavelengths, even though these may undergo refraction significant enough to bend an upward ray path back down to Earth (which occurs in HF skywave propagation). So I think it doesn't make sense to conflate the two by combining this portion of the article with the EIWG article (although it may make sense to add an appropriate reference that explains how the concepts are related). — Preceding unsigned comment added by 128.18.41.68 (talk) 15:47, 27 June 2014 (UTC)

I agree with the above—if I understand it correctly and it is correct, which I am not up to verifying. (Is there a reference for this?) I see three possibilities:

1. If the math in the section of the Ionosphere#Mechanism_of_refraction article already is covered in Earth–ionosphere waveguide, then summarize that section and, if necessary, say something like, "For more information, including equations, see [link to the specific section of that article]."
2. If it's not in the waveguide article but should be, move it there and summarize it here.
3. If User talk:128.18.41.68 is correct, the concepts are only related, and there is need to explain their relationship and their differences in both articles, being sure to cover why someone might get them confused.

Did I miss anything? Thanks, Geekdiva (talk) 10:06, 24 July 2014 (UTC)

Layer vs Region

There is a variety of nomenclature in the article for layers. E.g. "D region" vs "D-rgeion" vs "D layer". Which is which? And should they be consistent for E & F regions/layers too? — Preceding unsigned comment added by 193.63.181.95 (talk) 18:54, 24 June 2015 (UTC)

Beyond Earth

Other planets have ionospheres, as even the Venus Wiki links to this one. I would say it would be good to change the specific Earth references to the broader term of planet, however the specific data on Earth's ionosphere is lkely good to keep I think. — Preceding unsigned comment added by 2610:130:116:1800:2CEA:8348:6FDC:6BC4 (talk) 02:21, 25 October 2016 (UTC)

Ionized or Neutral

In the second paragraph of Geophysics, it reads "This portion of the atmosphere is ionized". I believe this claim is inaccurate, at least misleading. In the context of astronomy, "an atmosphere is ionized" indicates that the number fraction of ion is larger than neutral particle. However, this is not true for earth ionosphere. The atmosphere stays neutral all the way to very upper part of the exosphere. See Figure 7.7 in Kivelson & Russell 1995 or http://www.physics.usyd.edu.au/~cairns/teaching/lecture16/img20.gif

I added "partially" 2601:240:C901:D8E0:5CD5:56F0:722:E953 (talk) 15:36, 26 May 2017 (UTC)

References

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Discovery and Aurora

I got to this page through reading about Aurora.

The two are very much related, so it was strange to read here that a first hypothesis of electrically conducting regions occurred in 1839, and then jumps to Marconi. The page on Aurora suggests a knowledge of electrical layers in the atmosphere back in the 1700's, and gives many examples of the gradual understanding via effects of the Auroa — such as telegraph operators working without batteries. 94.247.186.130 (talk) 17:23, 11 February 2023 (UTC)

History of discovery

This section seems to have most of the pertinent information but I would like to re-write the section so that it flows better.I will also verify the references and add some more Mkomboti (talk) 05:08, 3 April 2023 (UTC)