by APOD Robot » Wed Jan 15, 2020 5:07 am
Iridescent Clouds over Sweden
Explanation: Why would these clouds multi-colored? A relatively rare phenomenon in clouds known as
iridescence can bring up unusual colors vividly or even a whole
spectrum of colors simultaneously. These
polar stratospheric clouds, also known as
nacreous and mother-of-pearl clouds, are formed of small
water droplets of nearly uniform size. When the
Sun is in the right position and, typically, hidden from direct view,
these thin clouds can be seen significantly
diffracting sunlight in a nearly coherent manner, with
different colors being deflected by different amounts. Therefore,
different colors will come to the observer from slightly
different directions. Many
clouds start with uniform regions that could show
iridescence but quickly become too thick, too mixed, or too angularly far from the
Sun to exhibit striking colors. The featured image and an
accompanying video were taken late last year over
Ostersund,
Sweden.
[url=https://apod.nasa.gov/apod/ap200115.html] [img]https://apod.nasa.gov/apod/calendar/S_200115.jpg[/img] [size=150]Iridescent Clouds over Sweden[/size][/url]
[b] Explanation: [/b] Why would these clouds multi-colored? A relatively rare phenomenon in clouds known as [url=https://www.atoptics.co.uk/droplets/irid1.htm]iridescence[/url] can bring up unusual colors vividly or even a whole [url=https://www.nasa.gov/directorates/heo/scan/spectrum/overview/index.html]spectrum[/url] of colors simultaneously. These [url=https://en.wikipedia.org/wiki/Polar_stratospheric_cloud]polar stratospheric[/url] [url=https://en.wikipedia.org/wiki/Cloud_iridescence]clouds[/url], also known as [url=https://apod.nasa.gov/apod/ap200110.html]nacreous[/url] and mother-of-pearl clouds, are formed of small [url=https://www.atoptics.co.uk/droplets/clouds.htm]water droplets[/url] of nearly uniform size. When the [url=https://apod.nasa.gov/apod/sun.html]Sun[/url] is in the right position and, typically, hidden from direct view, [url=http://cimss.ssec.wisc.edu/wxwise/class/iredsnce.html]these thin clouds[/url] can be seen significantly [url=http://www.exploratorium.edu/snacks/diffraction/index.html]diffracting[/url] sunlight in a nearly coherent manner, with [url=https://youtu.be/VljrlBkJUl0]different colors[/url] being deflected by different amounts. Therefore, [url=https://en.wikipedia.org/wiki/Iridescence]different colors[/url] will come to the observer from slightly [url=http://www.kaushik.net/avinash/wp-content/uploads/2010/02/many_different_directions.jpg]different directions[/url]. Many [url=https://en.wikipedia.org/wiki/Cloud_iridescence]clouds[/url] start with uniform regions that could show [url=https://apod.nasa.gov/apod/ap140708.html]iridescence[/url] but quickly become too thick, too mixed, or too angularly far from the [url=https://solarsystem.nasa.gov/solar-system/sun/in-depth/]Sun[/url] to exhibit striking colors. The featured image and an [url=https://youtu.be/VljrlBkJUl0]accompanying video[/url] were taken late last year over [url=https://www.youtube.com/watch?v=E0z1BqhtyLA]Ostersund[/url], [url=https://en.wikipedia.org/wiki/Sweden]Sweden[/url].
[table][tr][td=left][url=http://asterisk.apod.com/discuss_apod.php?date=200114][b]<< Previous APOD[/b][/url][/td] [td=center][url=http://asterisk.apod.com/view_retro.php?date=0115][b]This Day in APOD[/b][/url][/td] [td=right][url=http://asterisk.apod.com/discuss_apod.php?date=200116][b]Next APOD >>[/b][/url][/td][/tr][/table]