CENAP zum Polarlicht

[Mark]

Hallo,
hier ein ganz nett geschriebener Artikel zum Polarlicht:

CENAP Newsticker

Grüße,
Mark

[Peter Broich]

Re: CENAP zum Polarlicht. Schön. Danke Mark. *NM*

[jan lameer]

Hi Mark !

I haven't thoroughly read the article, but I very much like the satellite picture.
As far as I can judge, it greatly shows the different locations of the discrete electron aurora (over southern Norway) and the diffuse proton aurora over Denmark.
The latitudal difference in location between both type of auroras pretty much agrees in this pic with the theoretical difference of about 500 kilometers.
The idea of proton aurora is that the incoming proton on average collides 2700 times with atmospheric atoms and easily pics up an electron during those collisions. It then becomes a neutral hydrogen atom and can travel any direction it wants, usually towards the equator (that is southward in the northern hemisphere).
The fast neutral H can again loose its electron in a following collision and becomes a proton again that has to travel (spiral down) according to the local magnetic fieldlines.
The diffuse proton arc over Denmark is also known as the Hydrogen Arc or simply as "diffuse aurora". It is quite hard to notice this during a severe storm; as an observer you usually only notice that "the sky isn't so clear anymore". Once you recognize the phenomenon, it is easier to see it under perfect sky conditions.
One of the interesting aspects of this phenomenon is that quite a large charge potential builds up: negative (electrons) over southern Norway and positive (protons) over Denmark. After having caused aurora, the protons (and electrons) are still “free” and repell each other. Supposedly they travell upwards again, out into space and by that create the impression of “black aurora”. I’ve only observed that twice (12 April 2001 and xx March 2001).

Well, I’d say this satellite picture is one for history.
Coming week (may be this weekend allready) I’ll post my pics of last weeks spectacle. Apart from some very nice pics (If I may say so myself ), I’ve also recorded a fisheye picture that might have some scientific (well, amateur ...) meaning. It shows the same effect that I recorded on 6/7 March 2000 and that I couldn’t explain yet. I’d say it shows how the inner Van Allen belt heats up by first “making” blue Nitrogen high aurora before it produces the red SAR (Stable Aurora Red) – Arc that turns the entire sky red over lower latitudes during severe storms.

Oh well, I’ll try and post the pics soon and see what you all think of it.
(X9 earth directed in 2-3 weeks ?)
Greetings, JanL

[jan lameer]

Hi Mark !

I haven't thoroughly read the article, but I very much like the satellite picture
(http://science.nasa.gov/spaceweather/au ... europe.jpg ).
As far as I can judge, it greatly shows the different locations of the discrete electron aurora (over southern Norway) and the diffuse proton aurora over Denmark.
The latitudal difference in location between both type of auroras pretty much agrees in this pic with the theoretical difference of about 500 kilometers.
The idea of proton aurora is that the incoming proton on average collides 2700 times with atmospheric atoms and easily pics up an electron during those collisions. It then becomes a neutral hydrogen atom and can travel any direction it wants, usually towards the equator (that is southward in the northern hemisphere).
The fast neutral H can again loose its electron in a following collision and becomes a proton again that has to travel (spiral down) according to the local magnetic fieldlines.
The diffuse proton arc over Denmark is also known as the Hydrogen Arc or simply as "diffuse aurora". It is quite hard to notice this during a severe storm; as an observer you usually only notice that "the sky isn't so clear anymore". Once you recognize the phenomenon, it is easier to see it under perfect sky conditions.
One of the interesting aspects of this phenomenon is that quite a large charge potential builds up: negative (electrons) over southern Norway and positive (protons) over Denmark. After having caused aurora, the protons (and electrons) are still “free” and repell each other. Supposedly they travell upwards again, out into space and by that create the impression of “black aurora”. I’ve only observed that twice (12 April 2001 and xx March 2001).

Well, I’d say this satellite picture is one for history.
Coming week (may be this weekend allready) I’ll post my pics of last weeks spectacle. Apart from some very nice pics (If I may say so myself ), I’ve also recorded a fisheye picture that might have some scientific (well, amateur ...) meaning. It shows the same effect that I recorded on 6/7 March 2000 and that I couldn’t explain yet. I’d say it shows how the inner Van Allen belt heats up by first “making” blue Nitrogen high aurora before it produces the red SAR (Stable Aurora Red) – Arc that turns the entire sky red over lower latitudes during severe storms.

Oh well, I’ll try and post the pics soon and see what you all think of it.
(X9 earth directed in 2-3 weeks ?)
Greetings, JanL

[jan lameer]

Hi Mark !

I haven't thoroughly read the article, but I very much like the satellite picture
(http://science.nasa.gov/spaceweather/au ... europe.jpg ).
As far as I can judge, it greatly shows the different locations of the discrete electron aurora (over southern Norway) and the diffuse proton aurora over Denmark.
The latitudal difference in location between both type of auroras pretty much agrees in this pic with the theoretical difference of about 500 kilometers.
The idea of proton aurora is that the incoming proton on average collides 2700 times with atmospheric atoms and easily pics up an electron during those collisions. It then becomes a neutral hydrogen atom and can travel any direction it wants, usually towards the equator (that is southward in the northern hemisphere).
The fast neutral H can again loose its electron in a following collision and becomes a proton again that has to travel (spiral down) according to the local magnetic fieldlines.
The diffuse proton arc over Denmark is also known as the Hydrogen Arc or simply as "diffuse aurora". It is quite hard to notice this during a severe storm; as an observer you usually only notice that "the sky isn't so clear anymore". Once you recognize the phenomenon, it is easier to see it under perfect sky conditions.
One of the interesting aspects of this phenomenon is that quite a large charge potential builds up: negative (electrons) over southern Norway and positive (protons) over Denmark. After having caused aurora, the protons (and electrons) are still “free” and repell each other. Supposedly they travell upwards again, out into space and by that create the impression of “black aurora”. I’ve only observed that twice (12 April 2001 and xx March 2001).

Well, I’d say this satellite picture is one for history.
Coming week (may be this weekend allready) I’ll post my pics of last weeks spectacle. Apart from some very nice pics (If I may say so myself ), I’ve also recorded a fisheye picture that might have some scientific (well, amateur ...) meaning. It shows the same effect that I recorded on 6/7 March 2000 and that I couldn’t explain yet. I’d say it shows how the inner Van Allen belt heats up by first “making” blue Nitrogen high aurora before it produces the red SAR (Stable Aurora Red) – Arc that turns the entire sky red over lower latitudes during severe storms.

Oh well, I’ll try and post the pics soon and see what you all think of it.
(X9 earth directed in 2-3 weeks ?)
Greetings, JanL

[Wolfgang Dzieran]

Hi Jan,
your explanation of the satellite picture is great! My first view was: "yes, there is aurora and some cities...." But with your explanation of the different types of aurora, I had a great second view to it. Do you know other pictures which are showing this difference of proton and electron aurora as well?
I'm very interested in your pics ! They will be graet, too!

Wolfgang
from Bad Lippspringe near Paderborn

[jan lameer]

Hi Wolfgang !

At

http://www.berkeley.edu/news/media/rele ... auror.html

you can find more (UV)pics. The article explains it in depth.
Also in the "Aurora watchers handbook" )U. of Alaska at Fairbanks) you can find some pics and explanations.

[jan lameer]

Hi Wolfgang !

At

http://www.berkeley.edu/news/media/rele ... auror.html

you can find more (UV)pics. The article explains it in depth.
Also in the "Aurora watchers handbook" (U. of Alaska at Fairbanks) you can find some pics and explanations

[Thorsten]

Moin...

Versuche mal folgenden Link:

http://www.nordlicht.ch/aurora/bilder/part8.pdf

Gruß Thorsten