APOD: Mt Hood and a Lenticular Cloud (2013 Apr 17)

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APOD: Mt Hood and a Lenticular Cloud (2013 Apr 17)

Postby APOD Robot » Wed Apr 17, 2013 4:06 am

Image Mt Hood and a Lenticular Cloud

Explanation: What kind of cloud is next to that mountain? A lenticular. This type of cloud forms in air that passes over a mountain, rises up again, and cools past the dew point -- so what molecular water carried in the air condenses into droplets. The layered nature of some lenticular clouds may make them appear, to some, as large alien spaceships. In this case, the mountain pictured is Mt. Hood located in Oregon, USA. Lenticular clouds can only form when conditions are right -- for example this is first time this astrophotographer has seen a lenticular cloud at night near Mt. Hood. The above image was taken in mid-March about two hours before dawn.

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Re: APOD: Mt Hood and a Lenticular Cloud (2013 Apr 17)

Postby geckzilla » Wed Apr 17, 2013 4:13 am

Clouds and the effects of light reflecting off and passing through them sometimes still baffle me. Today's picture is one of those times. How is it illuminated? Moonlight, I presume. Still, it seems odd.
Just call me "geck" because "zilla" is like a last name.

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Re: APOD: Mt Hood and a Lenticular Cloud (2013 Apr 17)

Postby stowaway » Wed Apr 17, 2013 4:19 am

Oh come on! Anybody can tell that's really a flying saucer.

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Re: APOD: Mt Hood and a Lenticular Cloud (2013 Apr 17)

Postby Ann » Wed Apr 17, 2013 4:58 am

Today's APOD is very fascinating, but I'm frustrated because I can't identiy the background stars. Can anyone help me?

Ann
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Re: APOD: Mt Hood and a Lenticular Cloud (2013 Apr 17)

Postby alter-ego » Wed Apr 17, 2013 5:12 am

geckzilla wrote:Clouds and the effects of light reflecting off and passing through them sometimes still baffle me. Today's picture is one of those times. How is it illuminated? Moonlight, I presume. Still, it seems odd.

Ann wrote:Today's APOD is very fascinating, but I'm frustrated because I can't identiy the background stars. Can anyone help me?
Ann


The bright star on the right is Altair and on the left is Cassiopeia's gamma Cas, Caph, and Shedir. The moon is just rising under Altair (behind the mountain) so it is not a reasonable light source for the cloud. The suspect light source I think are the ground lights below. The cloud could be farther away from the mountain and the town (Government Camp), so the illumination could be more from the side of the cloud than directly under it. Also the lights on the mountain, behind the ridge, could easily be bright enough especially if you consider the likely skyward reflected component off the snow (the ski areas are on the other side of that ridge).

Correction: I was too early with date/time. The moon rises later, possibly after the sunrise.
Last edited by alter-ego on Wed Apr 17, 2013 6:48 am, edited 1 time in total.
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Re: APOD: Mt Hood and a Lenticular Cloud (2013 Apr 17)

Postby saturno2 » Wed Apr 17, 2013 5:51 am

Lenticular cloud is an UFO :)

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Re: APOD: Mt Hood and a Lenticular Cloud (2013 Apr 17)

Postby Ann » Wed Apr 17, 2013 6:06 am

Thank you very much, alter-ego! :D

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Re: APOD: Mt Hood and a Lenticular Cloud (2013 Apr 17)

Postby Boomer12k » Wed Apr 17, 2013 6:56 am

Something from my neck of the woods. On a VERY clear day, I can go to a hill, and see 5 mountains, including Mt. Hood, from Salem. Mt. Jefferson, Mt. Hood, Mt. Adams. Mt. Rainier, and Mt. St. Helens. I think those are it....it is a very rare event. Maybe 1 or 2 days in the Summer.

Beautiful picture....long exposure photography brings out allot...

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Re: APOD: Mt Hood and a Lenticular Cloud (2013 Apr 17)

Postby brixham bill » Wed Apr 17, 2013 8:19 am

I think this excellent picture shows both lenticular (above) and rotor clouds (immediately below). Lenticular clouds usually have relatively smooth airflow and the rising air on the upwind side is often used by glider pilots to reach great altitudes. The rotor cloud is in the lee of the mountain and is extremely turbulent. Such turbulence caused the loss of a Boeing 707 near Mt Fuji in Japan. On that occasion, the humidity was lower and the extreme turbulence was not revealed by a visible rotor cloud. (http://www.pilotfriend.com/disasters/crash/boac911.htm)

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Re: APOD: Mt Hood and a Lenticular Cloud (2013 Apr 17)

Postby fausto.lubatti » Wed Apr 17, 2013 8:22 am

Excellent shot, thanks for sharing!

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Re: APOD: Mt Hood and a Lenticular Cloud (2013 Apr 17)

Postby MargaritaMc » Wed Apr 17, 2013 8:34 am

alter-ego wrote:
Ann wrote:Today's APOD is very fascinating, but I'm frustrated because I can't identiy the background stars. Can anyone help me?
Ann


The bright star on the right is Altair and on the left is Cassiopeia's gamma Cas, Caph, and Shedir. The moon is just rising under Altair (behind the mountain) so it is not a reasonable light source for the cloud. The suspect light source I think are the ground lights below. The cloud could be farther away from the mountain and the town (Government Camp), so the illumination could be more from the side of the cloud than directly under it. Also the lights on the mountain, behind the ridge, could easily be bright enough especially if you consider the likely skyward reflected component off the snow (the ski areas are on the other side of that ridge).

Correction: I was too early with date/time. The moon rises later, possibly after the sunrise.

Have you any thoughts about the stars on the far right of the photo? Just above and slightly to the left of the tent. When I first read what you had posted, alter-ego, I thought that you meant that one of these was Altair. Then you mentioned that Altair was directly above the mountain. So I thought I'd ask!
Margarita
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Re: APOD: Mt Hood and a Lenticular Cloud (2013 Apr 17)

Postby neufer » Wed Apr 17, 2013 11:27 am

stowaway wrote:
alter-ego wrote:
geckzilla wrote:
Clouds and the effects of light reflecting off and passing through them sometimes still baffle me. Today's picture is one of those times. How is it illuminated? Moonlight, I presume. Still, it seems odd.

The suspect light source I think are the ground lights below. The cloud could be farther away from the mountain and the town (Government Camp), so the illumination could be more from the side of the cloud than directly under it. Also the lights on the mountain, behind the ridge, could easily be bright enough especially if you consider the likely skyward reflected component off the snow (the ski areas are on the other side of that ridge).

Oh come on! Anybody can tell that's really a flying saucer.
http://en.wikipedia.org/wiki/Timberline_Lodge_ski_area wrote:
<<Timberline Lodge ski area is one of a few ski areas in the United States with most of the skiable terrain below the main lodge. It is located on the south face of Mount Hood, about 60 miles east of Portland. The lodge was constructed between 1936 and 1938 as a Works Progress Administration project during the Great Depression. That year, Timberline opened as Oregon's first destination ski resort with a portable rope tow. The next year, the Magic Mile chairlift opened, as well as Silcox Hut, which sits about one thousand vertical feet and a mile above the main lodge, and was the original unloading and warming hut.

Summer skiing and summer race camps began at Timberline in 1956. Before the Palmer chairlift was constructed in 1983 (which provides access above the 7,000-foot level), the conditions at Timberline allowed skiing from the Mile November through July or August. With the Palmer, a skiable surface is available year round. Timberline is the only ski area in the states with lift accessed skiing and snowboarding all twelve months of the year. Ski and snowboard camps draw thousands of people to the slopes during the months of June, July and August.>>
http://en.wikipedia.org/wiki/Mount_Hood_Skibowl wrote:
<<Mount Hood Skibowl is a recreation area on Mount Hood located near Government Camp, Oregon. It is the largest night ski area in the United States, and the total skiable area encompasses an area of 960 acres (388 ha) (about two thirds of this is lit). The resort is the closest ski venue to Portland, with an elevation of 3,600 feet at the lodge, rising to just over 5,000 feet at the summit. The average snowfall at the area is 300 inches, with an average consolidated base around 100 inches and 65 marked trails.>>
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Re: APOD: Mt Hood and a Lenticular Cloud (2013 Apr 17)

Postby neufer » Wed Apr 17, 2013 11:40 am

http://earthobservatory.nasa.gov/IOTD/view.php?id=39786 wrote:
<<Mount Hood is located within the Cascade Range of the western United States, and it is the highest peak in Oregon (3,426 meters). The Cascade Range is characterized by a line of volcanoes associated with a slab of oceanic crust that is subducting, or descending underneath, the westward-moving, continental crust of North America. Magma generated by the subduction process rises upward through the crust and feeds a line of active volcanoes that extends from northern California in the United States to southern British Columbia in Canada.

While hot springs and steam vents are still active on Mount Hood, the last eruption from the volcano occurred in 1866. The volcano is considered dormant, but still actively monitored. Separate phases of eruptive activity produced pyroclastic flows and lahars that carried erupted materials down all of the major rivers draining the volcano. Gray volcanic deposits extend southwards along the banks of the White River (image lower left) and form several prominent ridges along the southeast to southwest flanks of the volcano. The deposits contrast sharply with the green vegetation on the lower flanks of the volcano.

The Mount Hood stratovolcano—a typically cone-shaped structure formed by layered lava flows and explosive eruption deposits—hosts twelve mapped glaciers along its upper flanks. Like other glaciers in the Pacific Northwest, the Hood glaciers have been receding due to global warming, and they have lost an estimated 61 percent of their volume over the past century. The predicted loss of glacial meltwater under future warming scenarios will have significant effects on regional hydrology and water supplies.>>
Art Neuendorffer

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pictures i dont like to see on apod

Postby ritwik » Wed Apr 17, 2013 1:10 pm

1.clouds
2.analemma
3.aurora
4.moon

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Re: APOD: Mt Hood and a Lenticular Cloud (2013 Apr 17)

Postby stephen63 » Wed Apr 17, 2013 1:15 pm

neufer wrote:
http://earthobservatory.nasa.gov/IOTD/view.php?id=39786 wrote:
<<Mount Hood is located within the Cascade Range of the western United States, and it is the highest peak in Oregon (3,426 meters). The Cascade Range is characterized by a line of volcanoes associated with a slab of oceanic crust that is subducting, or descending underneath, the westward-moving, continental crust of North America. Magma generated by the subduction process rises upward through the crust and feeds a line of active volcanoes that extends from northern California in the United States to southern British Columbia in Canada.

While hot springs and steam vents are still active on Mount Hood, the last eruption from the volcano occurred in 1866. The volcano is considered dormant, but still actively monitored. Separate phases of eruptive activity produced pyroclastic flows and lahars that carried erupted materials down all of the major rivers draining the volcano. Gray volcanic deposits extend southwards along the banks of the White River (image lower left) and form several prominent ridges along the southeast to southwest flanks of the volcano. The deposits contrast sharply with the green vegetation on the lower flanks of the volcano.

The Mount Hood stratovolcano—a typically cone-shaped structure formed by layered lava flows and explosive eruption deposits—hosts twelve mapped glaciers along its upper flanks. Like other glaciers in the Pacific Northwest, the Hood glaciers have been receding due to global warming, and they have lost an estimated 61 percent of their volume over the past century. The predicted loss of glacial meltwater under future warming scenarios will have significant effects on regional hydrology and water supplies.>>


It's hard to believe that one teaspoon of neutron star material weighs as much as Mt. Hood!

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Re: APOD: Mt Hood and a Lenticular Cloud (2013 Apr 17)

Postby Ron-Astro Pharmacist » Wed Apr 17, 2013 5:10 pm

With a little imagination that thing could be mistaken for a - flying sausage :lol2:
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Re: APOD: Mt Hood and a Lenticular Cloud (2013 Apr 17)

Postby Starmon » Wed Apr 17, 2013 5:33 pm

Anyone else having problems opening this image? I can't :oops:
Think cosmic !!
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Re: APOD: Mt Hood and a Lenticular Cloud (2013 Apr 17)

Postby Boomer12k » Wed Apr 17, 2013 11:49 pm

MargaritaMc wrote:
alter-ego wrote:
Ann wrote:Today's APOD is very fascinating, but I'm frustrated because I can't identiy the background stars. Can anyone help me?
Ann


The bright star on the right is Altair and on the left is Cassiopeia's gamma Cas, Caph, and Shedir. The moon is just rising under Altair (behind the mountain) so it is not a reasonable light source for the cloud. The suspect light source I think are the ground lights below. The cloud could be farther away from the mountain and the town (Government Camp), so the illumination could be more from the side of the cloud than directly under it. Also the lights on the mountain, behind the ridge, could easily be bright enough especially if you consider the likely skyward reflected component off the snow (the ski areas are on the other side of that ridge).

Correction: I was too early with date/time. The moon rises later, possibly after the sunrise.

Have you any thoughts about the stars on the far right of the photo? Just above and slightly to the left of the tent. When I first read what you had posted, alter-ego, I thought that you meant that one of these was Altair. Then you mentioned that Altair was directly above the mountain. So I thought I'd ask!
Margarita


Margarita,
See Picture...Altair is the far right star...the view is East, from my city, Salem, Oregon on the 17 of March. The Moon is down in the lower left, just under Jupiter, same color text, UNDER the horizon, so, Maybe I did not have the right day, but this is about 4:30 in the morning. MY SOFTWARE shows that the Moon was setting in the west at this time around the 25th, which means it was actually starting the new phases...and was not VISIBLE for MID-MARCH...Earlier than the 25th, it was under the horizon. The Moon was UP and to the SOUTH early in the month, but was down, under the horizon at this time of morning, from about the 8th on...so Mid Month, it would not be up and not in the picture, or even "behind" Mount Hood...or the other mountains.

Hope this helps put things in perspective.

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Re: APOD: Mt Hood and a Lenticular Cloud (2013 Apr 17)

Postby eyesoars » Thu Apr 18, 2013 1:52 am

Not just a lenticular cloud, it's a 'stacked lenticular' cloud.

These are common in the Rockies, and can be quite beautiful.
The layers and smooth edges of the cloud demonstrate the
laminar (non-turbulent) nature of the airflow that creates them.

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Re: APOD: Mt Hood and a Lenticular Cloud (2013 Apr 17)

Postby MargaritaMc » Thu Apr 18, 2013 8:31 am

Thank you very much, Boomer 12k, for the helpful star map!
And what a lovely part of the world to live in.
Margarita
"In those rare moments of total quiet with a dark sky, I again feel the awe that struck me as a child. The feeling is utterly overwhelming as my mind races out across the stars. I feel peaceful and serene."
— Dr Debra M. Elmegreen, Fellow of the AAAS


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