Astronomy, Photography and Weather

General Category => Weather & Atmospherics => Topic started by: martinastro on October 05, 2009, 06:05:57 pm



Title: Possible Volcanic Sunset?
Post by: martinastro on October 05, 2009, 06:05:57 pm
Took these on Oct 4th of a long duration sunset after-glow with long pink rays fanning up from the sunset point in a completely clear sky. Looked very similar to a volcanic sunset to me. Seen the same strange sunsets alot lately but this was the most dramatic so far.

(http://i38.tinypic.com/inqtqo.jpg)

(http://i36.tinypic.com/qs8rdd.jpg)


Title: Re: Possible Volcanic Sunset?
Post by: Big Dipper on October 05, 2009, 10:03:21 pm
I'm no expert but I tend to agree with you Martin. Whatever, I like those shots in their own right - thanks for sharing.


Title: Re: Possible Volcanic Sunset?
Post by: martinastro on October 06, 2009, 04:24:09 pm
Thanks very much Andy. I asked Les Cowley about these strange sunsets and got the following response...

I'm a decided sceptic about 'volcanic sunsets and twilights' because they have been hyped and there is a tendency to label every colourful wilight as 'volcanic'. However, we have been having a run of them with bright yellow twilight arches and pronounced purple light. They have been spectacular here in Norfolk.

Some information from a colleague in Germany week before last was that idar measurements by the Meteorological Observatory Hohenpeißenberg, southern Germany show that there is indeed a homogeneous layer of mainly sulfuric acid droplets extending upwards from the tropopause up to 20 km high with a maximum density at 13-16 km. This is more or less evenly spread around the northern hemisphere and is 'thought' to be a remnant from the Sarychev eruption. The optical density is enough to produce some twilight effects.

There have been eruptions since Sarychev but this material is evenly spread and the twilight reports are widespread at moderately high altitudes. We were at Fuerteventura three weeks ago (28N) and the twilights there were 'normal' although enhanced ones were reported at higher latitudes.




Title: Re: Possible Volcanic Sunset?
Post by: Roman White on October 06, 2009, 06:22:20 pm
Martin, if the twilight in your image is 'volcanic' (imho it is), then I have seen many & many of them in the recent days (months?). Almost every clear & semi-clear evening I see the purple skies in west. I'm already getting bored with this, thus take no images. Maybe soon it will a be surprising to report here a normal sunset, lol.  ;D


Title: Re: Possible Volcanic Sunset?
Post by: martinastro on October 06, 2009, 07:00:00 pm
How could you be bored with a volcanic sunset?, I'd rather have those than an ordinary sunset anytime.

Les Cowley is skeptical that these are genuine volcanic sunsets though.


Title: Re: Possible Volcanic Sunset?
Post by: markt on October 07, 2009, 07:07:21 am
Nice pickies Martin!  These types of sunsets are certainly more common at the moment.  Nice piece of detective work though - I can understand Les scepticism but the info from Germany about the Sulphur layer ties in very nicely with what we've been observing and documenting on this forum.  Either way, I think the morale of the story is that we should enjoy the view regardless of the mechanism that is producing them.   ::)


Title: Re: Possible Volcanic Sunset?
Post by: rjgjr on October 07, 2009, 04:13:07 pm
Either way, these sunsets and sunrises have been spectacular the past several months!


Title: Re: Possible Volcanic Sunset?
Post by: Roman White on October 07, 2009, 04:48:11 pm
Les Cowley is skeptical that these are genuine volcanic sunsets though.
Then how he explains about that pink colour?

How could you be bored with a volcanic sunset?
Nearly the same way as I didn't observe anything last night. The sky was clear! but it was cold (+4C), foggy (double cold) and the full moonlight vanished most of the stars away. Plus the lack of time as always on weekdays.  :-\


Title: Re: Possible Volcanic Sunset?
Post by: brianb on October 07, 2009, 07:31:18 pm
Quote
Nearly the same way as I didn't observe anything last night. The sky was clear! but it was cold (+4C), foggy (double cold) and the full moonlight vanished most of the stars away.
No fog here but intermittent cloud cover, probably averaging 70% ... 4C and a nasty breeze with it, no fog though. I stuck it till dawn ... been getting very little clear sky recently, have to use what little is available.


Title: Re: Possible Volcanic Sunset?
Post by: martinastro on October 07, 2009, 07:50:34 pm
It was clear here all night until dawn, and it was the coldest night so far this season with a light frost. No fog either which was annoying because I was hoping for some for fogbows. Venus and Mercury before dawn looked great. Last chance tonight for some observing/photography before the cold front moves in on Thurs night.


Title: Re: Possible Volcanic Sunset?
Post by: John9929 on October 07, 2009, 10:00:28 pm
And here they are taken about 0620BST. Venus at top, Mercury above the finger of cloud, Saturn just below Mercury and left of that same finger. Couldn't get an image from my garden so had to travel to a vantage point.
(http://i38.tinypic.com/2lavjb9.jpg)


Title: Re: Possible Volcanic Sunset?
Post by: martinastro on October 07, 2009, 10:30:41 pm
Excellent stuff John!!, could be worth imaging again in the morning.


Title: Re: Possible Volcanic Sunset?
Post by: Big Dipper on October 07, 2009, 10:36:37 pm
Personally I, too would be grateful for any kind of sunset at the moment as I want to try out a new (well 'new' to me) Sigma zoom lens which I've just received.

That's a nice capture John and something I desperately want to see & image myself with it being Mercury's best morning apparition for us 'northerners' of the year.


Title: Re: Possible Volcanic Sunset?
Post by: rjgjr on October 08, 2009, 12:35:29 am
That's a great shot John. All the hills and mountaisns around just about delete any viewing from here.


Title: Re: Possible Volcanic Sunset?
Post by: JohnC on October 09, 2009, 02:24:48 pm
Good to get some confirmation re. these sunsets - they've certainly given us some wonderful photo ops. Lovely glow there, Martin.


Title: Re: Possible Volcanic Sunset?
Post by: martinastro on October 11, 2009, 07:09:20 pm
Thanks John, did you anything this evening?

Just had another stunning 'volcanic sunset' here in the form of an intense pink wedge/arc with numerous rays fanning up in high contrast against a crisp blue sky.


Title: Re: Possible Volcanic Sunset?
Post by: martinastro on October 11, 2009, 11:25:41 pm
Here's the vivid after-glow from this evening at two times showing the change in height and appearance.

(http://i35.tinypic.com/34zf1c7.jpg)

(http://i38.tinypic.com/2v9tehl.jpg)