Air Glow Petrel Cove

[Paul Haese]

Went to Petrel Cove last night. Heaps of cloud all night but we got a few minutes where is cleared enough to see it. The sky was quite bright and it was clearly evident in the base images. Pity the sky did not co-operate.

[CapturingTheNight (Greg)]

Lovely image Paul. Great foreground. Shame about the aurora no show. What a fizzer.

[Paul Haese]

Yeah, I guess sometime this year or next I will get a clear night with good air glow and aurora down at Petrel cove. Patience is needed yet.

I cannot complain too much this image was taken on 1st of March. My first green aurora, just before moon rise. That was KP5 and raged for 18 hours. I only got 20 frames before moon rise. I was aiming for the comet which is on the right hand side of the image.

[gregbradley]

Nice. I like the aurora image, that's a beauty.
What site do you use to monitor the aurora?

Greg.

[Paul Haese]

Originally Posted by gregbradley

Nice. I like the aurora image, that's a beauty.
What site do you use to monitor the aurora?

Greg.

Hi Greg, it should read what sites. I will put the list of the sites I use at present.

http://www.swpc.noaa.gov/rt_plots/kp_3d.html

http://www.swpc.noaa.gov/alerts/alerts_timeline.html

http://helios.swpc.noaa.gov/ovation/

http://www.gi.alaska.edu/ Go to aurora page and click on map of southern hemisphere.

http://www.ips.gov.au/Geophysical/2/1

http://dx.qsl.net/propagation/

http://www.spaceweather.com/ Left hand column

As you can see there is a few to check out, but from that you can glean what is going on.

[gregbradley]

Thanks Paul.

Greg.

[ourkind (Carlos)]

Nice shot Paul and the one with the comet is great!

That green air glow certainly would've fooled me into thinking I was capturing an aurora. I don't think I've ever seen air glow that bright.

Thanks for posting that great list too

[Antu]

Wonderful composition, Paul ! The colors are very nice indeed.

[lacad01 (Adam)]

Lovely shot. Out of curiosity, what actually causes the green glow

[Paul Haese]

Thanks guys.

Adam I think the glow is photoionised ions caused by the interaction with the solar wind and particles eminating from the Sun. In fact there are several factors which cause it, but given the activity from the CME I would say the above was the cause. I could be completely wrong though.

[gregbradley]

Originally Posted by Paul Haese

Thanks guys.

Adam I think the glow is photoionised ions caused by the interaction with the solar wind and particles eminating from the Sun. In fact there are several factors which cause it, but given the activity from the CME I would say the above was the cause. I could be completely wrong though.

Airglow is pretty common. I almost always see it in my nightscape shots. To a greater or lesser degree. It sometimes has subtle magenta bands. Its easier to see it in a time lapse. It moves and has currents and is almost like thin cloud.

Greg.

[lacad01 (Adam)]

Cool, thanks for the info

[multiweb (Marc)]

That's really cool. Great colors. That would make a good advertisement for that photoshop plugin HLVG.

[Larryp (Laurie)]

Very well composed, and quite ethereal

[geoffsims (Geoff)]

Airglow (and it's variation with time) is actually quite a complex subject, and "airglow" actually refers to a whole host of atmospheric emissions. Most commonly though, the green airglow you see in photographs is the atomic oxygen 557.7 nm emission which, incidentally, is the same one that appears in the aurora (but caused by a different mechanism).

It seems to create quite a stir these days (and with many misconceptions) mainly because of the high-sensitivity of DSLRs being able to consistently record the fine structure and colouration. But it has always been there.

Airglow is pretty common

Actually, it is not merely "common", it is there 100% of the time. Airglow is the main reason the sky (in between the stars) is not completely dark. There are other factors (e.g., unresolved stars/galaxies, zodiacal light), but airglow is the dominant component. Put your hand up to the sky on a dark night and away from light pollution - you will see a silhouette. The background "glow" is airglow.

But yes, it's intensity does vary on both short (second to minutes) and long (decadal; solar cycle) time scales, with the background sky brightness being significantly brighter (0.4 mag/arcsec^2 across the optical V-band) during solar maximum.

[Antu]

Originally Posted by Paul Haese

Thanks guys.

Adam I think the glow is photoionised ions caused by the interaction with the solar wind and particles eminating from the Sun. In fact there are several factors which cause it, but given the activity from the CME I would say the above was the cause. I could be completely wrong though.

Paul, let me correct you a little. This is aurora which is caused by collision of charged particles (i.e. solar wind) with atoms in the upper atmosphere. The origin of airglow is due to chemoluminescence (molecules dissociate by daytime solar UV radiation, then subsequent chemical reactions produce excited states that decay with the emission of photons).

Clear skies !

[rogerg (Roger)]

Strong green!

I can only presume airglow tends to different colours in different places/landscapes, as I never ever get green in the wheatbelt where I shoot. Always orange/brown.

Was it obvious to the eye? Did it appear green at all to the eye?

[Paul Haese]

No colour Roger but it was quite bright to the eye. We could see it through the gaps in the cloud.