Canopus calculations show the auroral oval ovet Germany and the Netherlands now!
Color green, so no big deal but there was some RISK factor.
strange...
Canopus oval over Germany 20:20 UT
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Ulrich Rieth
Re: Canopus oval over Germany 20:20 UT
Hi Jan !
I think that a Canopus oval over Germany of less then yellow color means just nothing.
If you look at the color code, the deviations at the magnetometers on the Churchill line in Canada and the US have to be of a certain strength for each color.
but for visible aurora in Europe it needs at least a huge drop at Kiruna or the Norwegian magnetometers of some 600 - 800 nT.
So, Canopus in green means just no activity.
Regards
Ulrich
I think that a Canopus oval over Germany of less then yellow color means just nothing.
If you look at the color code, the deviations at the magnetometers on the Churchill line in Canada and the US have to be of a certain strength for each color.
but for visible aurora in Europe it needs at least a huge drop at Kiruna or the Norwegian magnetometers of some 600 - 800 nT.
So, Canopus in green means just no activity.
Regards
Ulrich
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jan lameer
Re: Canopus oval over Germany 20:20 UT
> Hi Ulrich!
I indeed know that.
It is just so funny to see it.
But, as we are talking about it, would there be any physical aurora over us, perhaps very weak?
Or is it just a calculation artefact, meaning nothing at all.
But then why isn't Canopus turned off as it usually is during quiet times?
Could we see Aurora overhead now in a very long exposed fish eye picture from a very dark location in Germany?
I indeed know that.
It is just so funny to see it.
But, as we are talking about it, would there be any physical aurora over us, perhaps very weak?
Or is it just a calculation artefact, meaning nothing at all.
But then why isn't Canopus turned off as it usually is during quiet times?
Could we see Aurora overhead now in a very long exposed fish eye picture from a very dark location in Germany?
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max
Re: Canopus oval over Germany 20:20 UT
Hoi Jan and Ulrich,
1. Largely depending horizontal sight conditions one would need around 100 - 300 nT disturbance in Dombaas ( http://geo.phys.uit.no/knum/dob/ ) for photographic PL.
As your and my pics show, there might be special conditions of the oval combined with extremly good sight that enable photographic PL even below 100 nT in Dombaas. But this is rare.
2. The algorythms used for Canopus have several drawbacks, especially for use here in Europe. To mention some:
A. They use centered dipole magnetic coordinates that put us closer to the oval then the ACGM coordinates do. They can not use ACGM because it is a very non-orthogonal system, thus resulting in deformed maps.
B. The maps however are in geodetic coordinates. There is much question about plotting a magnetic coordinate system over a geodetic coordinate system. Ever tried making an accurate GPS map of a picture taken from an airplane ?
C. They extrapolate a N-S magnetometerline in central Canada to the other half of the world but the DMSP pics in the Auroral Watcher's Handbook show that magnetic / auroral activity is not isotropic at all, even not on scales of a few hundreds of km.
To my experience, this all results in a graph showing more intense and more southerly activity then there is in reality. That's also why I use the Norwegian stacked H : our own European Churchill line. Canopus is a nice thing to look at but one should take its "predictions" with a lot of salt.
> Could we see Aurora overhead now in a very long exposed fish eye
> picture from a very dark location in Germany?
"Now": Monday night I was on the spot where I observed 6 weeks in april / may and even at 3/4 moon the shadows were more intense then the shadows of the aurora during the april 11 storm. So the answer would be "no, just moonlight".
During new moon one would need very good horizontal sight. And personally I wouldn't use a fish eye but a 24 or 28 mm, with its small side along the horizon. Or even two camera's.
Asuming no light pollution -so one can expose up to the natural sky luminosity limit- in this case I think there would be no discernable aurora on the pic and probably no auroral (after)glow -taking into account other measurements. On some other days however pics can reveal a vague red auroral (after)glow at this level of Canopus.
Max
1. Largely depending horizontal sight conditions one would need around 100 - 300 nT disturbance in Dombaas ( http://geo.phys.uit.no/knum/dob/ ) for photographic PL.
As your and my pics show, there might be special conditions of the oval combined with extremly good sight that enable photographic PL even below 100 nT in Dombaas. But this is rare.
2. The algorythms used for Canopus have several drawbacks, especially for use here in Europe. To mention some:
A. They use centered dipole magnetic coordinates that put us closer to the oval then the ACGM coordinates do. They can not use ACGM because it is a very non-orthogonal system, thus resulting in deformed maps.
B. The maps however are in geodetic coordinates. There is much question about plotting a magnetic coordinate system over a geodetic coordinate system. Ever tried making an accurate GPS map of a picture taken from an airplane ?
C. They extrapolate a N-S magnetometerline in central Canada to the other half of the world but the DMSP pics in the Auroral Watcher's Handbook show that magnetic / auroral activity is not isotropic at all, even not on scales of a few hundreds of km.
To my experience, this all results in a graph showing more intense and more southerly activity then there is in reality. That's also why I use the Norwegian stacked H : our own European Churchill line. Canopus is a nice thing to look at but one should take its "predictions" with a lot of salt.
> Could we see Aurora overhead now in a very long exposed fish eye
> picture from a very dark location in Germany?
"Now": Monday night I was on the spot where I observed 6 weeks in april / may and even at 3/4 moon the shadows were more intense then the shadows of the aurora during the april 11 storm. So the answer would be "no, just moonlight".
During new moon one would need very good horizontal sight. And personally I wouldn't use a fish eye but a 24 or 28 mm, with its small side along the horizon. Or even two camera's.
Asuming no light pollution -so one can expose up to the natural sky luminosity limit- in this case I think there would be no discernable aurora on the pic and probably no auroral (after)glow -taking into account other measurements. On some other days however pics can reveal a vague red auroral (after)glow at this level of Canopus.
Max
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