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| CALIFORNIA RED—Photographed by Pillar to Post contributor Phyllis Shess taken on the highway
between Blythe, CA and 29 Palms, CA, September, 2015. Images on this posting were from sources
other than National Geographic
magazine. |
What makes the sky so red or orange or
both at sunset? For an answer we read a
terrific explanation by meteorologist Stephen Corfidi, who was interviewed by
National Geographic magazine’s Amanda Fiegl, in her article “Red sky at night:
The Science of Sunsets.”
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| Amanda Fiegl |
Q: Do dust
and air pollution make sunsets more dramatic?
A: No, you
often hear that, but—assuming you mean typical pollution in the lower
atmosphere—it's a myth. It's actually the opposite: Large particles in the
lower atmosphere tend to mute and muddy the colors because they absorb more
light and scatter all the wavelengths more or less equally, so you don't get
that dramatic filtering effect. In areas with a lot of haze, you don't
typically see the types of sunsets that are likely to appear on a wall
calendar—or in, say, National Geographic.
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| Stephen Corfidi |
Q: Okay, so
let's talk about the typical Earthling's perspective. Why do we see more orange
and red colors in the sky during sunrise and sunset than we do at other times
of day?
A: When a
beam of sunlight strikes a molecule in the atmosphere, what's called
"scattering" occurs, sending some of the light's wavelengths off in
different directions. This happens millions of times before that beam gets to
your eyeball at sunset.
The two main
molecules in air, oxygen and nitrogen, are very small compared to the
wavelengths of the incoming sunlight—about a thousand times smaller. That means
that they preferentially scatter the shortest wavelengths, which are the blues
and purples. Basically, that's why the daytime sky is blue. The daytime sky
would actually look purple to humans were it not for the fact that the
sensitivity of our eyes peaks in the middle [green] part of the spectrum—that
is, closer to blue than to purple.
But at
sunset, the light takes a much longer path through the atmosphere to your eye
than it did at noon, when the sun was right overhead. And that is enough to
make a big difference as far as our human eyes are concerned. It means that
much of the blue has scattered out long before the light reaches us. The blues
could be somewhere over the West Coast, leaving a disproportionate amount of
oranges and reds as that beam of light hits the East Coast.
For the rest of Amanda’s interviews go
to the following address and learn why butterflies and reindeer see sunsets
different than humans:
http://news.nationalgeographic.com/news/2013/10/131027-sunset-sky-change-color-red-clouds-science/
MORE ORANGE SKIES:
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DAILY ABSTRACTS—Sunsets combined with clouds give
skywatchers daily abstract paintings to admire.
In this scene Mother Nature has painted a version of North and South
America.
|
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GO WEST--Another reason life in general is
better on the West Coast aside from the East Coast getting sunset leftovers on
a daily basis is being able to peer into the Western skies at sunset to see
images like Comet PanSTARRS on its 2013 trip around our sun.
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NO LIMITS—Jacqueline Jimenez recently posted
this sunset image from Playas de Tijuana.
This portion of the beach is just a few steps south of the border fence
that juts out into the ocean separating two nations. Makes one understand the view is just as
beautiful on either side.
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| Thank you and Amen. |
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| PHONE IN--Just when Phyllis Shess decided to buy a camera to replace the one she lost in Madrid, then her android phone captures an image like the one above off of Punta Razza, Florida. November 2015. |
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DAWN’S A YAWN compared with the sheer brilliance
of sunsets as noted in this image of day break in Cienfuegos, Cuba, April 2015. Image by Pillar
to Post contributor Mike Shess.
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