APOD: Unusual Red Glow Over Minnesota (2009 Feb 17)
-
- Commander
- Posts: 977
- Joined: Tue Jan 06, 2009 5:55 pm
- AKA: Sputnick
Re: Unusual Red Glow Over Minnesota (2009 February 17)
I think it's sunset light coming in from the window (or even two windows) on the other side of the plane .. you can see part of the windowframe as the 'L' in the left side blaze of light .. the image of that window is cast onto the window nearest the observer, the colour also maybe reflecting in the moisture in the air below the aircraft, but I don't think so, I think it's a double reflection, from two windows, on the one window.
Duty done .. the rain will stop as promised with the rainbow.
"Abandon the Consensus for Individual Thought"
"Abandon the Consensus for Individual Thought"
Re: Unusual Red Glow Over Minnesota (2009 February 17)
Does nobody realize that the artist formerly known as the artist formerly known as Prince is from Minnesota? This effect may be a defective prop escaped from a Purple Rain stage show.Skywatcher2 & geckzilla & MikeB wrote:orange rain
- Chris Peterson
- Abominable Snowman
- Posts: 18573
- Joined: Wed Jan 31, 2007 11:13 pm
- Location: Guffey, Colorado, USA
- Contact:
Re: Unusual Red Glow Over Minnesota (2009 February 17)
The Sun was on the same side of the plane as the window, so it couldn't have come from windows on the opposite side.aristarchusinexile wrote:I think it's sunset light coming in from the window (or even two windows) on the other side of the plane .. you can see part of the windowframe as the 'L' in the left side blaze of light .. the image of that window is cast onto the window nearest the observer, the colour also maybe reflecting in the moisture in the air below the aircraft, but I don't think so, I think it's a double reflection, from two windows, on the one window.
Again, we need to keep in mind the conditions under which the photographer took the image. He looked outside and saw a bright glow, which he photographed. I find it hard to believe that he would have been fooled by a reflection off the window.
Chris
*****************************************
Chris L Peterson
Cloudbait Observatory
https://www.cloudbait.com
*****************************************
Chris L Peterson
Cloudbait Observatory
https://www.cloudbait.com
- geckzilla
- Ocular Digitator
- Posts: 9180
- Joined: Wed Sep 12, 2007 12:42 pm
- Location: Modesto, CA
- Contact:
Re: Unusual Red Glow Over Minnesota (2009 February 17)
I don't know enough about reptiles to really qualify for the title of herpetologist but I do enjoy them and animals quite a lot. As usual I know just enough to be dangerous and not enough to be a professional. No offense taken. You aren't the first to do that and I am quite a geek anyway.MikeB wrote:Oops... I meant geckzilla, NOT geekzilla. My apologies!
(You must be a herper.)
Just call me "geck" because "zilla" is like a last name.
- neufer
- Vacationer at Tralfamadore
- Posts: 18805
- Joined: Mon Jan 21, 2008 1:57 pm
- Location: Alexandria, Virginia
Re: Unusual Red Glow Over Minnesota (2009 February 17)
It seems like most of the "high frequency structure" comes from the underlying patterns of buildings on the ground.Chris Peterson wrote:My main objection to this idea is that to me, the orange area is in clear, sharp focus. It doesn't appear in the least unfocused. It contains high frequency structure.neufer wrote:If it actually is outside (and not an out of focus window reflection)...
PARSIMONIOUS, a. Sparing in the use or expenditure of money; covetous; near; close. It differs from frugal, in implying more closeness or narrowness of mind, or an attachment to property somewhat excessive, or a disposition to spend less money that is necessary or honorable.Chris Peterson wrote:I can't say that I've ever seen a jet leave something like a persistent cloud behind while at low altitude. But I've seen a number of natural clouds that look just like this, and a few of them lit up orange by sunset, also looking just like this. A natural cloud/virga formation seems a more parsimonious explanation than something artificial.neufer wrote:...my guess is that it is some kind of contrail effect...possibly left over from a previous jet.
Art Neuendorffer
Re: Unusual Red Glow Over Minnesota (2009 February 17)
I thought contrails appeared at the tropopause (the boundary layer between troposphere and stratosphere, at a much higher altitude than the subject matter in this photo) where it is very cold (even in Minnesota terms). An old jet fighter pilot once told me he would lurk just below the tropopause waiting for the enemy to descend through it and show himself with his contrail.
- geckzilla
- Ocular Digitator
- Posts: 9180
- Joined: Wed Sep 12, 2007 12:42 pm
- Location: Modesto, CA
- Contact:
Re: Unusual Red Glow Over Minnesota (2009 February 17)
I thought I might post some links to various photos of sunset reflections in plane windows that show vaguely similar patterns to the original photo. So far it's much more difficult to find them than it was the orange rain and they aren't nearly as similar.
scratches
http://www.flickr.com/photos/toddbox/288835117/
smudges
http://www.flickr.com/photos/jhirsch/2503890504/
flares? refractions? reflections?
http://www.flickr.com/photos/bertobox/194939486/
smudgy filaments. possibly the closest so far. The biggest difference is that the window itself is in focus rather than the terrain. So it's not very similar at all in that regard.
http://www.flickr.com/photos/schuberts/ ... 0/sizes/l/
Here's a photo where the clouds are clearly the orange blobs and have nothing to do with reflections
http://www.flickr.com/photos/iamkimiam/1077718212/
More orange rain from a plane, just not nearly as striking as the APOD
http://www.flickr.com/photos/chicanerii/2265141492/
Here is a blurred reflection from a window with the ground in focus. However, no orange in the reflection. No sunset.
http://www.flickr.com/photos/liz/59464015/
This is clearly a reflection of someone's shirt and the chair:
http://www.flickr.com/photos/jabrink/1463465441/
Oh well, that's enough devil's advocate for me.
scratches
http://www.flickr.com/photos/toddbox/288835117/
smudges
http://www.flickr.com/photos/jhirsch/2503890504/
flares? refractions? reflections?
http://www.flickr.com/photos/bertobox/194939486/
smudgy filaments. possibly the closest so far. The biggest difference is that the window itself is in focus rather than the terrain. So it's not very similar at all in that regard.
http://www.flickr.com/photos/schuberts/ ... 0/sizes/l/
Here's a photo where the clouds are clearly the orange blobs and have nothing to do with reflections
http://www.flickr.com/photos/iamkimiam/1077718212/
More orange rain from a plane, just not nearly as striking as the APOD
http://www.flickr.com/photos/chicanerii/2265141492/
Here is a blurred reflection from a window with the ground in focus. However, no orange in the reflection. No sunset.
http://www.flickr.com/photos/liz/59464015/
This is clearly a reflection of someone's shirt and the chair:
http://www.flickr.com/photos/jabrink/1463465441/
Oh well, that's enough devil's advocate for me.
Just call me "geck" because "zilla" is like a last name.
- Chris Peterson
- Abominable Snowman
- Posts: 18573
- Joined: Wed Jan 31, 2007 11:13 pm
- Location: Guffey, Colorado, USA
- Contact:
Re: Unusual Red Glow Over Minnesota (2009 February 17)
That's not the structure I'm referring to. I'm talking about the linear, illuminated structures running through the cloud, which look identical to virga or rain sheets.neufer wrote:It seems like most of the "high frequency structure" comes from the underlying patterns of buildings on the ground.
I expect you know I meant this in its usual scientific sense:PARSIMONIOUS, a. Sparing in the use or expenditure of money; covetous; near; close. It differs from frugal, in implying more closeness or narrowness of mind, or an attachment to property somewhat excessive, or a disposition to spend less money that is necessary or honorable. :roll:
In science, parsimony is preference for the least complex explanation for an observation. This is generally regarded as good when judging hypotheses. Occam's razor also states the "principle of parsimony"; however, parsimony is a preference rather than a general principle.
Chris
*****************************************
Chris L Peterson
Cloudbait Observatory
https://www.cloudbait.com
*****************************************
Chris L Peterson
Cloudbait Observatory
https://www.cloudbait.com
Re: Unusual Red Glow Over Minnesota (2009 February 17)
This picture reminds me of the following article från October 2008:
http://www.thisislondon.co.uk/standard/ ... xpand=true
Maybe the answer could be the same.
Clas Svahn
Stockholm
http://www.thisislondon.co.uk/standard/ ... xpand=true
Maybe the answer could be the same.
Clas Svahn
Stockholm
- neufer
- Vacationer at Tralfamadore
- Posts: 18805
- Joined: Mon Jan 21, 2008 1:57 pm
- Location: Alexandria, Virginia
Odd Hodge Splodge
Very Interesting; thanks, Clas.ufosvahn wrote:This picture reminds me of the following article från October 2008:
http://www.thisislondon.co.uk/standard/ ... xpand=true
Maybe the answer could be the same.
Clas Svahn Stockholm
Art Neuendorffer
- neufer
- Vacationer at Tralfamadore
- Posts: 18805
- Joined: Mon Jan 21, 2008 1:57 pm
- Location: Alexandria, Virginia
Re: Unusual Red Glow Over Minnesota (2009 February 17)
The least complex explanation probably wouldn't include the word "parsimonious."Chris Peterson wrote:I expect you know I meant this in its usual scientific sense:neufer wrote:PARSIMONIOUS, a. Sparing in the use or expenditure of money; covetous; near; close. It differs from frugal, in implying more closeness or narrowness of mind, or an attachment to property somewhat excessive, or a disposition to spend less money that is necessary or honorable.
In science, parsimony is preference for the least complex explanation for an observation. This is generally regarded as good when judging hypotheses.
Then what do you make of the photographer Tyler Blessing's comment: "Try not to cut yourself on Occam's razor!" ?Chris Peterson wrote: Occam's razor also states the "principle of parsimony"; however, parsimony is a preference rather than a general principle.
Well, virga or cloud perhaps, but it tain't rain!Chris Peterson wrote: I'm talking about the linear, illuminated structures running through the cloud, which look identical to virga or rain sheets.
Actual raindrops (that are big enough to fall) scatter light very poorly
except forwards, backwards & rainbows...which is why we CAN see rainbows:
http://antwrp.gsfc.nasa.gov/apod/ap070912.html
http://antwrp.gsfc.nasa.gov/apod/ap060702.html
And which is also why the following examples
must be low clouds or dissipating fog and NOT RAIN:
http://farm4.static.flickr.com/3200/268 ... 0397b1.jpg
http://tinyurl.com/dk26zy
http://tinyurl.com/cnk6kb
Real "Orange Rain" :
Art Neuendorffer
- Chris Peterson
- Abominable Snowman
- Posts: 18573
- Joined: Wed Jan 31, 2007 11:13 pm
- Location: Guffey, Colorado, USA
- Contact:
Re: Unusual Red Glow Over Minnesota (2009 February 17)
Virga and rain are one and the same thing, except that the former term is used for rain that evaporates before it reaches the ground. Their optical properties are the same. I'm inclined to think this is virga, since I think with rain the ground would be less clear, but since we're really only seeing the part that's illuminated, it's hard to say for sure. The structure shows droplet sheeting, which isn't something you'd normally find in clouds. Of course, there's an ill defined area where clouds and rain overlap.neufer wrote:Well, virga or cloud perhaps, but it tain't rain!Chris Peterson wrote: I'm talking about the linear, illuminated structures running through the cloud, which look identical to virga or rain sheets.
Well, we could be looking at nearly total forward scatter here. The Sun isn't far off-axis from the direction of the shot. However, you've neglected refraction and internal reflection. Raindrops do refract and reflect light as well, which may be what's producing this effect. I have seen this exact effect from the ground in obvious virga, so there's no doubt in my mind that this could be the same.Actual raindrops (that are big enough to fall) scatter light very poorly
except forwards, backwards & rainbows...
Chris
*****************************************
Chris L Peterson
Cloudbait Observatory
https://www.cloudbait.com
*****************************************
Chris L Peterson
Cloudbait Observatory
https://www.cloudbait.com
Re: Unusual Red Glow Over Minnesota (2009 February 17)
I thought virga is rain or snow that doesn't reach the ground.neufer wrote:Well, virga or cloud perhaps, but it tain't rain!
virga: (weather) Rain or snow that is dissipated in falling and does not reach the ground, commonly appearing in trails descending from a cloud layer.
- neufer
- Vacationer at Tralfamadore
- Posts: 18805
- Joined: Mon Jan 21, 2008 1:57 pm
- Location: Alexandria, Virginia
Re: Unusual Red Glow Over Minnesota (2009 February 17)
Outside of the ultra dry southwest, virga almost always refers to SNOW that doesn't reach the ground.Chris Peterson wrote:Virga and rain are one and the same thing, except that the former term is used for rain that evaporates before it reaches the ground. Their optical properties are the same. I'm inclined to think this is virga, since I think with rain the ground would be less clear, but since we're really only seeing the part that's illuminated, it's hard to say for sure. The structure shows droplet sheeting, which isn't something you'd normally find in clouds. Of course, there's an ill defined area where clouds and rain overlap.neufer wrote:Well, virga or cloud perhaps, but it tain't rain!Chris Peterson wrote: I'm talking about the linear, illuminated structures running through the cloud, which look identical to virga or rain sheets.
Evaporating virga rain might include drops small enough to Lambert scatter a little:
http://antwrp.gsfc.nasa.gov/apod/ap080529.html
but this seems unlikely in this bright orange Minnesota situation.
We are certainly NOT looking at nearly total forward scatter here.Chris Peterson wrote:Well, we could be looking at nearly total forward scatter here.neufer wrote:Actual raindrops (that are big enough to fall) scatter light very poorly
except forwards, backwards & rainbows...
The Sun is due west-south-west while we are looking DOWN and to the northwest.
I've NOT neglected refraction or internal reflection... nor have these APOD's:Chris Peterson wrote:However, you've neglected refraction and internal reflection. Raindrops do refract and reflect light as well, which may be what's producing this effect.
http://antwrp.gsfc.nasa.gov/apod/ap070912.html
http://antwrp.gsfc.nasa.gov/apod/ap060702.html
Was it rain virga or snow virga?Chris Peterson wrote:I have seen this exact effect from the ground in obvious virga, so there's no doubt in my mind that this could be the same.
Last edited by neufer on Tue Feb 24, 2009 5:23 pm, edited 1 time in total.
Art Neuendorffer
- neufer
- Vacationer at Tralfamadore
- Posts: 18805
- Joined: Mon Jan 21, 2008 1:57 pm
- Location: Alexandria, Virginia
Re: Unusual Red Glow Over Minnesota (2009 February 17)
Not a lot of trials/tails in http://apod.nasa.gov/apod/ap090217.htmlbystander wrote:virga: (weather) Rain or snow that is dissipated in falling and does not reach the ground,
commonly appearing in trails descending from a cloud layer.
http://en.wikipedia.org/wiki/Cirrus_cloud wrote:
<<Cirrus clouds are characterized by thin, wisplike strands, often accompanied by tufts, leading to their common (non-standard) name of mare's tail. Many cirrus clouds produce hair like filaments made of the heavier ice crystals that precipitate from them. These "fall streaks", a form of virga, often indicate the difference in the motion of air (wind shear) between the upper part of the cirrus cloud and the air below it. Sometimes the top of the cirrus cloud is moving rapidly above a slower layer of air, or the streak is falling into a faster moving lower layer. The directions of these winds can also vary.>>
Art Neuendorffer
- Chris Peterson
- Abominable Snowman
- Posts: 18573
- Joined: Wed Jan 31, 2007 11:13 pm
- Location: Guffey, Colorado, USA
- Contact:
Re: Unusual Red Glow Over Minnesota (2009 February 17)
Well, I live in the dry southwest. I've seen both rain and snow virga, but I do think the term is more generally used (everywhere) for rain. I also find that many people I talk to outside the west have never even heard the word.neufer wrote:Outside of the ultra dry southwest, virga almost always refers to SNOW that doesn't reach the ground.
This is a quarter hour before sunset on the equinox. The Sun's azimuth is 268°, and the camera azimuth is about 282°. That's a difference of only 14°. That said, I don't really think it's scatter. Simple reflection off of water droplets makes more sense.We are certainly NOT looking at nearly total forward scatter here.
The Sun is due west-south-west while we are looking DOWN and to the northwest.
Always rain. I've never seen snow virga (or snowfall) between me and the Sun look anything other than gray. (Snowfall on sunny days isn't uncommon in my part of the Rockies.)Was it rain virga or snow virga?Chris Peterson wrote:I have seen this exact effect from the ground in obvious virga, so there's no doubt in my mind that this could be the same.
Chris
*****************************************
Chris L Peterson
Cloudbait Observatory
https://www.cloudbait.com
*****************************************
Chris L Peterson
Cloudbait Observatory
https://www.cloudbait.com
Re: Unusual Red Glow Over Minnesota (2009 February 17)
Plus, snowfall in September is also rare even in Minnesota
-
- Asternaut
- Posts: 6
- Joined: Mon Feb 23, 2009 6:32 am
Re: Unusual Red Glow Over Minnesota (2009 February 17)
To try to get things a bit more precise for everyone on the angles involved, the sun at that time of day on that date at that location would better be described as west-west-west-west-south-west.neufer wrote: The Sun is due west-south-west while we are looking DOWN and to the northwest.
For reference as to the camera direction, one easily identifiable road that runs exactly east-west is the road that runs alongside the barn area (near the bottom right of the photo) to the southwest end of the training track. I think the photographer's description as "north of west" is somewhat more accurate than saying "northwest".
- neufer
- Vacationer at Tralfamadore
- Posts: 18805
- Joined: Mon Jan 21, 2008 1:57 pm
- Location: Alexandria, Virginia
Re: Unusual Red Glow Over Minnesota (2009 February 17)
Well, I worked at NOAA's World Weather Building in Camp Springs, Md., for about 30 yearsChris Peterson wrote:Well, I live in the dry southwest. I've seen both rain and snow virga, but I do think the term is more generally used (everywhere) for rain.neufer wrote:Outside of the ultra dry southwest, virga almost always refers to SNOW that doesn't reach the ground.
I also find that many people I talk to outside the west have never even heard the word.
and I can't remember anyone there use virga for anything other than snow.
(I'm sure the same is true for Minnesota.)
The camera is looking DOWN at more than 14°.Chris Peterson wrote:This is a quarter hour before sunset on the equinox.neufer wrote:We are certainly NOT looking at nearly total forward scatter here.
The Sun is due west-south-west while we are looking DOWN and to the northwest.
The Sun's azimuth is 268°, and the camera azimuth is about 282°.
That's a difference of only 14°. That said, I don't really think it's scatter.
Simple reflection off of water droplets makes more sense.
That said, the sun appears pretty darn small when reflected off of a sphere:
If you see sunlit gray virga in some other direction it is rain virga:Chris Peterson wrote:Always rain. I've never seen snow virga (or snowfall) between me and the Sun look anything other than gray.neufer wrote:Was it rain virga or snow virga?Chris Peterson wrote:I have seen this exact effect from the ground in obvious virga, so there's no doubt in my mind that this could be the same.
(Snowfall on sunny days isn't uncommon in my part of the Rockies.)
Art Neuendorffer
Re: Unusual Red Glow Over Minnesota (2009 February 17)
Is it just me or does that vortex have straight hexagonal sides like polar saturnneufer wrote:(snip)
If you see sunlit gray virga in some other direction it is rain virga:
- neufer
- Vacationer at Tralfamadore
- Posts: 18805
- Joined: Mon Jan 21, 2008 1:57 pm
- Location: Alexandria, Virginia
Re: Unusual Red Glow Over Minnesota (2009 February 17)
There's a hex on that town.BMAONE23 wrote:Is it just me or does that vortex have straight hexagonal sides like polar saturn
Art Neuendorffer
-
- Asternaut
- Posts: 6
- Joined: Mon Feb 23, 2009 6:32 am
Re: Unusual Red Glow Over Minnesota (2009 February 17)
Not that its relevant on the conclusions you're drawing, but just as another point of reference for everyone, TheSky6 says the sun set at 7:08 PM Minneapolis local time on 09/23/02. That would be within a minute of the time of the picture, not fifteen minutes.... assuming the camera's clock was accurate except for the time zone difference from where it was set.Chris Peterson wrote:This is a quarter hour before sunset on the equinox.
Re: Unusual Red Glow Over Minnesota (2009 February 17)
Some adjustment to the sunset time, I don't know how much, needs to be made for altitude.Skywatcher2 wrote:TheSky6 says the sun set at 7:08 PM Minneapolis local time on 09/23/02. That would be within a minute of the time of the picture, not fifteen minutes.
- geckzilla
- Ocular Digitator
- Posts: 9180
- Joined: Wed Sep 12, 2007 12:42 pm
- Location: Modesto, CA
- Contact:
Re: Unusual Red Glow Over Minnesota (2009 February 17)
Are you trying to use these photos to say that rain droplets can't be colored (yes, oversimplification, hopefully you know what I mean) orange by the sun? I'm confused.neufer wrote: I've NOT neglected refraction or internal reflection... nor have these APOD's:
http://antwrp.gsfc.nasa.gov/apod/ap070912.html
http://antwrp.gsfc.nasa.gov/apod/ap060702.html
Just call me "geck" because "zilla" is like a last name.
- Chris Peterson
- Abominable Snowman
- Posts: 18573
- Joined: Wed Jan 31, 2007 11:13 pm
- Location: Guffey, Colorado, USA
- Contact:
Re: Unusual Red Glow Over Minnesota (2009 February 17)
Maybe, but what matters if forward scatter is involved is the angle between the clouds and Sun, and that's quite small.neufer wrote:The camera is looking DOWN at more than 14°.
But we're talking here about the reflections off of billions of spheres. And of course, the illuminated area is still only a fraction as bright as the Sun itself.That said, the sun appears pretty darn small when reflected off of a sphere
Chris
*****************************************
Chris L Peterson
Cloudbait Observatory
https://www.cloudbait.com
*****************************************
Chris L Peterson
Cloudbait Observatory
https://www.cloudbait.com