Wheres my Blue Sky??????

A Few weeks ago I was amazed at the color of the sky. After a rainstorm, the clouds opened up and the sky was this Deep (Yet still light) Blue, the Clouds were fluffy and It all looked like a picture.. ALL THE TIME. It lasted for maybe 2 weeks. Now, Everything is… Bleh.. I mean the sky is obliviously still blue, but its not the same color. Insight on why it was so blue? Or is so I guess Grey now?

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Originally posted by Britx
A Few weeks ago I was amazed at the color of the sky. After a rainstorm, the clouds opened up and the sky was this Deep (Yet still light) Blue, the Clouds were fluffy and It all looked like a picture.. ALL THE TIME. It lasted for maybe 2 weeks. Now, Everything is… Bleh.. I mean the sky is obliviously still blue, but its not the same color. Insight on why it was so blue? Or is so I guess Grey now?

*Mods, please move if this isn't in the correct spot*

edit on 7/6/2011 by Britx because: (no reason given)

You don't even say where you are, so how could we possibly know? The sky is the same blue it has always been where I live.

It may have seemed bluer because of the darkness in the clouds surrounding the opening?

Yeah, here next to munich everything is like it's always been: Either we have the typical light blue bavarian sky with some clouds or a rainy, dark clouded day.
Today it looked like a typical summer day, light blue sky, some clouds in between and nearly 30°C.
(And even after Airplanes went by, there were no chemtrails, just normal contrails that faded away fast)

Tomorror until sundy i'll be in Sweden, i take a look at the sky, maybe it will different - though it hasn't been different the past few years i went there

Depends where you reside. After a couple of weeks of STRONG winds and odd rainfall, today (and part of yesterday) has some blue sky. Clouds are ever present, though.

All sorts of possible reasons, but the most obvious one is aircraft contrails - a consequence of our obsession with flying everywhere.

We do get good clearances at times, often after the passage of a cold front, but rarely are the skies across Europe or N America entirely clear this days. This was very apparent with the contrast in conditions in May last year whilst Ejya was erupting. Even when contrails aren't obvious, there is still very thin cirrus being produced by their passage (dozens an hour over some places) - and it's more noticeable on the horizon (obviously)

This study of the skies in 2003 may interest you - even when there are no obvious contrails, they are still there

hal.archives-ouvertes.fr...

Sorry, I completely spaced there. Im near Philadelphia. It Was raining before the skys turned deep blue. But when they did it lasted for a while and Im guessing it faded out.... to this grayish color that it is now.. I wish I would have gotten pictures to compare.

reply to post by Britx


It could be smog that is causing it to look gray or whitish gray. Here in the South we call it haze, but its still smog, just sounds better. Today, there is a lot of cumulus clouds and can still see blue sky and about 93degrees here in this part of N.C.

Some summer days the haze is very visible and has a bluish look to it in the distance.

Well if you get above the clouds and haze. It seems to be quite blue to me when I get above any haze and cloud layers when I am flying. Although if it is cirrus, I can not get above that, but the skies still look quite blue.

Where did this idea come about that the sky must always be perfectly blue, regardless of weather conditions?

reply to post by Britx


Then it could just be a haze of cirrostratus ahead of another weather system. If it rains again in the next 24 hours you'll know.

You can probably find a bunch of photos that include sky on flikr for your location that go back many years - why not check them out?

The sky color comes from two type of light scattering: "Rayleigh Scattering" and "Mie Scattering"

Rayleigh Scattering is what gives you the blue sky. It's from scattering of light from air molecules and very tiny particles.

Mie Scattering gives you the white color in the sky (and it's what makes clouds white). It's dependent on the larger particles of dust and water in the air. When there's less of this, you get bluer skies.

After a rain storm, the larger particulates are washed out of the air, which can give you a deeper blue sky. How quickly the white comes back is dependent on the weather.

hyperphysics.phy-astr.gsu.edu...

reply to post by Britx


You haven't noticed the blue sky? It's right above you, blue as ever. No changes here.

Originally posted by adeclerk
reply to post by Britx

 

You haven't noticed the blue sky? It's right above you, blue as ever. No changes here.

"right above you" is always where the sky is most blue, as there's far less particulates looking vertically than looking horizontally, and because the white Mie scattering mostly projects away from from the sun.

This can lead to perceived changes in blue sky depending on where you live, and and then where you move to. If you live on the lower regions of the south side of a valley in the northern hemisphere, then your average sky will be a LOT bluer than if you live on of the west side of a solitary hill.

Here's and extreme example. If you live in the Grand Canyon, then you'll be looking up a lot to see the sky, so it's going to seem bluer. It also generally runs east-west, so on average you'll be at right angles to the sun. Hence any river rafting trip you take in the Grand Canyon is going to give you bluer skies than normal.

[atsimg]http://files.abovetopsecret.com/images/member/b5edf38d69ea.jpg[/atsimg]


You can see how the blue varies with direction in any 360 degree panorama:
[atsimg]http://files.abovetopsecret.com/images/member/b7b00f4c6245.jpg[/atsimg]

Note the sky is bluest in the two regions that would be at right angles to the sun (assuming the sun is in the south here, the bluer regions are in the east and west.

The north sky (where the clouds are) is also whiter (Mie also scatters backwards, and I suspect direct reflection may play a part).

And of course, it's whitest near the horizon in every direction.

So think about where you live when you question how blue the sky is. What direction are you looking in? Where is the sun? How high are you looking? Can you see the horizon, or are there nearby hills?

And if you have memories of particularly blue skies, try to remember is any of this might have played a part in what you saw.

If yuo think chemtrails are making skies less blue then can you please comment on this issue??

www.abovetopsecret.com...

Thanks

reply to post by Uncinus


I don't need your fancy words, I believe what my eyes see, and they see blue skies!

ETA: I don't want us debunkers to lose credibility, so I must comment on that panorama. It is a bunch of photos stitched together, the variation is caused by having the camera on automatic exposure/white balance (thats why the darker parts of the sky correspond to the darker parts of the ground in the photo). Not that the sky can't vary, it's just not the best example.

reply to post by adeclerk


I disagree. The same pattern shows up on nearly every 360 panorama that has some blue sky, and makes perfect sense based on Mie scattering. The sky is bluer at right angles to the sun. Any good panorama should use a fixed exposure.

www.google.com...

[atsimg]http://files.abovetopsecret.com/images/member/25150bb082c9.jpg[/atsimg]

reply to post by Uncinus


Right but most 360 degree panoramas are stitched together by amateurs, you won't see as much variation in a photo from a true panoramic camera. But the variation certainly is there.

reply to post by adeclerk


I don't think this is that kind of thing . I've seen the patchy stitching you refer to, and it shows as vertical bands. Look at the original source

commons.wikimedia.org...:San_Agustin_360panorama_B.jpg

You can download a 10,000 pixel wide image from there. Here I've compressed and darkened it, to highlight the shape of the dark blue areas:

[atsimg]http://files.abovetopsecret.com/images/member/cbb8d880342a.jpg[/atsimg]

That's not a stitching artifact. It looks like a smooth curve - a function of the angles from the horizon and the sun. Exposure stitching problems look like straight lines, like:

[atsimg]http://files.abovetopsecret.com/images/member/f6c759f312b8.jpg[/atsimg]

(you can still the Mie variation in this image as well though).

reply to post by Uncinus


Gotcha, good explanation.

And if you are still not convinced, here's a large collection of single exposure 360 degree photos that show the same pattern:

www.0-360.com...

[atsimg]http://files.abovetopsecret.com/images/member/ef1a70803957.jpg[/atsimg]

(it's a bit less pronounced, because this type of lens has a reduced vertical range, but it's still there. Darkest blue high in the sky at right angles to the sun.

ETA - Although now I'm less sure about the 180 degree brightening, as most of those shots seem to show it darkest at 180 from the sun Bah!


ETA - But not all, phew. I think it must depend on the atmospheric conditions. The 180 degree brightening perhaps only occurring with water haze or something.




ETA - 360 Panorama from 30,000 feet (top of Everest) shows the same pattern from a different perspective. Also shows how the blue of the sky with increase with altitude, so you you moved from Denver to Los Angeles, then it's going to change.

www.photosfan.com...