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APOD: Lenticular Clouds Over Washington (2012 Nov 04)

Posted: Sun Nov 04, 2012 4:10 am
by APOD Robot
Image Lenticular Clouds Over Washington

Explanation: Are those UFOs near that mountain? No -- they are multilayered lenticular clouds. Moist air forced to flow upward around mountain tops can create lenticular clouds. Water droplets condense from moist air cooled below the dew point, and clouds are opaque groups of water droplets. Waves in the air that would normally be seen horizontally can then be seen vertically, by the different levels where clouds form. On some days the city of Seattle, Washington, USA, is treated to an unusual sky show when lenticular clouds form near Mt. Rainier, a large mountain that looms just under 100 kilometers southeast of the city. This image of a spectacular cluster of lenticular clouds was taken in 2008 December.

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Re: APOD: Lenticular Clouds Over Washington (2012 Nov 04)

Posted: Sun Nov 04, 2012 4:13 am
by genevb
This is a replay of the 2009-Feb-3 APOD, but the caption hasn't changed, so the "taken last December" statement is incorrect.
http://apod.nasa.gov/apod/ap090203.html

Re: APOD: Lenticular Clouds Over Washington (2012 Nov 04)

Posted: Sun Nov 04, 2012 5:53 am
by blergnaut
Of all websites, I wouldn't think APOD would mess up a post such as this. You refer to Mt. Rainier as a mountain, in the geologic sense it is only a volcano, NOT A MOUNTAIN! I know the whole Mount part is confusing, but it doesn't mean you get to remain 'ignant'!
-Your friendly pedantic neighbor

Re: APOD: Lenticular Clouds Over Washington (2012 Nov 04)

Posted: Sun Nov 04, 2012 6:00 am
by Chris Peterson
blergnaut wrote:Of all websites, I wouldn't think APOD would mess up a post such as this. You refer to Mt. Rainier as a mountain, in the geologic sense it is only a volcano, NOT A MOUNTAIN! I know the whole Mount part is confusing, but it doesn't mean you get to remain 'ignant'!
-Your friendly pedantic neighbor
Volcanoes are mountains, both technically and colloquially. Volcanism is one of the mechanisms of mountain building, after all!

Re: APOD: Lenticular Clouds Over Washington (2012 Nov 04)

Posted: Sun Nov 04, 2012 7:44 am
by darkgently
Oh come on guys, there are so many beautiful pictures out there to show us - why waste a day repeating one? I'm hoping this was just an oversight rather than a deliberate ploy!

Re: APOD: Lenticular Clouds Over Washington (2012 Nov 04)

Posted: Sun Nov 04, 2012 9:19 am
by Ann
blergnaut wrote:Of all websites, I wouldn't think APOD would mess up a post such as this. You refer to Mt. Rainier as a mountain, in the geologic sense it is only a volcano, NOT A MOUNTAIN! I know the whole Mount part is confusing, but it doesn't mean you get to remain 'ignant'!
-Your friendly pedantic neighbor
http://en.wikipedia.org/wiki/Olympus_Mons wrote:
Olympus Mons (Latin for Mount Olympus) is a large shield volcano on the planet Mars. By one measure, it has a height of nearly 22 km (14 mi).[3] This makes it the tallest mountain on any planet in the Solar System
Ann

Re: APOD: Lenticular Clouds Over Washington (2012 Nov 04)

Posted: Sun Nov 04, 2012 10:39 am
by henrystar
Chris Peterson wrote:
blergnaut wrote:Of all websites, I wouldn't think APOD would mess up a post such as this. You refer to Mt. Rainier as a mountain, in the geologic sense it is only a volcano, NOT A MOUNTAIN! I know the whole Mount part is confusing, but it doesn't mean you get to remain 'ignant'!
-Your friendly pedantic neighbor
Volcanoes are mountains, both technically and colloquially. Volcanism is one of the mechanisms of mountain building, after all!
Vulcanism, surely? My we ARE having a bad day at APOD!

Re: APOD: Lenticular Clouds Over Washington (2012 Nov 04)

Posted: Sun Nov 04, 2012 11:43 am
by zbvhs
My favorite lenticular cloud picture is a long-ago APOD showing a single lenticular cloud with what appreared to be wingtip vortices trailing downwind from the edges. I suppose these things could behave like lifting surfaces if pressure distributions were right. I did a search on "lenticular" and only got back today's APOD. By the way, down in Texas it's "ignernt". Don't know where people say "ignant".

Re: APOD: Lenticular Clouds Over Washington (2012 Nov 04)

Posted: Sun Nov 04, 2012 12:23 pm
by RedFishBlueFish
I am glad that this was repeated - since I missed it the first time. Surprising though that APOD does not have a longer institutional memory, for there are not likely that many people (all of whom are appreciated by us!) involved, and this is a striking image.


Except for sailplane pilots, no one wants to be in that picture, for though the clouds are beautiful, and look calm, this would not be a good day to be flying over or immediately to the east of the Cascades as there would be severe turbulence - which gliders simply call "lift".

The mountain (A "mountain" is any really big pile of dirt with notable relief - n.b. one can only claim pedanticy (sorely needed neologism) if one is correct: To paraphrase a current politician "Volcanoes are mountains my friend!") is about 14,400 feet (~4,390 m) high. As you can see, the bases of the lennies are that altitude or more. The contrails are probably ~30,000.

Mt Rain is one of the most beautiful, and most dangerous, volcanoes in the world. It is dangerous because it is thickly coated with glaciers, is still active, and is just up a river from Seattle. When Mt Rain erupts the resulting lahar (slurry of lava, ash, rocks and melted glaciers) will fill that river valley in the same manner as did the eruption of Mt Rain's sister - Saint Helens - a few years ago (which eruption was visible from Seattle).

We can hope all we want, but Mt Rain will erupt again and now is the time to take steps to ameliorate the damage this will cause. However, as with climate change, I doubt that any meaningful action will be taken until the disaster has occurred.

Still, a beautiful picture of an interesting phenomenon.

Re: APOD: Lenticular Clouds Over Washington (2012 Nov 04)

Posted: Sun Nov 04, 2012 12:25 pm
by RedFishBlueFish
zbvhs wrote:My favorite lenticular cloud picture is a long-ago APOD showing a single lenticular cloud with what appreared to be wingtip vortices trailing downwind from the edges. I suppose these things could behave like lifting surfaces if pressure distributions were right. I did a search on "lenticular" and only got back today's APOD. By the way, down in Texas it's "ignernt". Don't know where people say "ignant".
Try this search:

https://www.google.com/search?tbm=isch& ... qQHiyoGADw

You will be rewarded.

Re: APOD: Lenticular Clouds Over Washington (2012 Nov 04)

Posted: Sun Nov 04, 2012 1:46 pm
by MadMe

Re: APOD: Lenticular Clouds Over Washington (2012 Nov 04)

Posted: Sun Nov 04, 2012 2:21 pm
by geckzilla
darkgently wrote:Oh come on guys, there are so many beautiful pictures out there to show us - why waste a day repeating one? I'm hoping this was just an oversight rather than a deliberate ploy!
Sunday is typically repeat day at APOD. Surely you must have noticed before. I'll email the editors about the date incongruity.

Re: APOD: Lenticular Clouds Over Washington (2012 Nov 04)

Posted: Sun Nov 04, 2012 2:24 pm
by geckzilla
henrystar wrote:Vulcanism, surely? My we ARE having a bad day at APOD!
Nope.

Re: APOD: Lenticular Clouds Over Washington (2012 Nov 04)

Posted: Sun Nov 04, 2012 2:33 pm
by Chris Peterson
henrystar wrote:
Chris Peterson wrote:
blergnaut wrote:Of all websites, I wouldn't think APOD would mess up a post such as this. You refer to Mt. Rainier as a mountain, in the geologic sense it is only a volcano, NOT A MOUNTAIN! I know the whole Mount part is confusing, but it doesn't mean you get to remain 'ignant'!
-Your friendly pedantic neighbor
Volcanoes are mountains, both technically and colloquially. Volcanism is one of the mechanisms of mountain building, after all!
Vulcanism, surely?
Volcanism is the preferred term.

Re: APOD: Lenticular Clouds Over Washington (2012 Nov 04)

Posted: Sun Nov 04, 2012 2:46 pm
by Mokurai

Re: APOD: Lenticular Clouds Over Washington (2012 Nov 04)

Posted: Sun Nov 04, 2012 3:05 pm
by Beyond
Mokurai wrote:Two words: Mount Shasta.

http://images.google.com/search?num=10& ... unt+shasta
ooh, lotsa lenti's to see at your link. Some are colorful.
One thing i haven't seen around here (N/E CT.) in 15 or 20 years, is medium tall puffy clouds with dark flat bottoms, like they're all sitting on an invisible sheet of glass.

Re: APOD: Lenticular Clouds Over Washington (2012 Nov 04)

Posted: Sun Nov 04, 2012 3:25 pm
by LocalColor
We enjoy the repeats on Sundays as much as we enjoy the new photos on the other days of the week.

Thank you APOD.

Re: APOD: Lenticular Clouds Over Washington (2012 Nov 04)

Posted: Sun Nov 04, 2012 5:23 pm
by Boomer12k
Well....to throw in my two cents worth on this Volcanoes are not mountains thing....

I live in the Willamette Valley in Oregon, USA...from a hill only a few miles from my house, I can see the Cascade Mountain Range to the East of our city....5 Mountains can be seen on a very CLEAR DAY...Mt. St. Helens was one such mountain, we use to drive by it on the way up to Washington State. Darn thing was also a Volcano.... Volcanoes can be mountains...Mountains can be Volcanoes...No doubt in my mind...my car had a dusting of ash on it in May 1980...Those other 4 mountains....also VOLCANOES...

Experts say...that under the valley floor is buried....a 6 MILE HIGH MOUNTAIN....covered with mud....from the ice age mud flows...I hope it is not a volcano...

On the subject of Repeat APOD pictures....well, if you have not seen the picture before...it is new to you....and if you have seen it before....well, that just means you are free to go see something else sooner....Win...Win.... :D

Ann....You go girl....

:---[===] *

Re: APOD: Lenticular Clouds Over Washington (2012 Nov 04)

Posted: Sun Nov 04, 2012 5:39 pm
by neufer
APOD Robot wrote:
On some days the city of Seattle, Washington, USA, is treated to an unusual sky show when
lenticular clouds form near Mt. Rainier, a large mountain that looms just under 100 kilometers southeast of the city.
Kudos to an APOD that actually neglected ( :?: ) to translate kilometers into miles.
http://en.wikipedia.org/wiki/Metrication#Accidents_and_incidents wrote: <<Confusion over units during the process of metrication can sometimes lead to accidents. One of the most famous examples was during Canada's metrication: in 1983, an Air Canada Boeing 767, nicknamed the "Gimli Glider" after the incident, ran out of fuel in mid-flight. The incident was caused, in a large part, by the confusion over the conversion among litres, kilograms, and pounds, resulting in the aircraft receiving 22,300 pounds of fuel instead of the required 22,300 kg.

On 25 September 2009, the British Department for Transport published a draft version of legislation to amend its road signage legislation for comment. Amongst the proposed changes is an amendment to existing legislation to make dual unit height and width warning and restriction signs mandatory. This is justified in Paragraph 53 of the Impact Analysis by the text "... Based on records from Network Rail's incident logs since April 2008, approximately 10 – 12% of bridge strikes involved foreign lorries. This is disproportionately high in terms of the number of foreign lorries on the road network." This proposal was shelved with the change of government in 2010, though many bridges are now dual signed.

Only the United States continues to see significant popular opposition to metrication, the main objections being based in localism, tradition, cultural aesthetics, economic impact, or distaste for measures viewed as "foreign". Japan had significant popular opposition at one time for similar reasons. Popular opposition in the United Kingdom exists to a lesser degree and can be associated with anti-European Union sentiment. France, where the measures were largely invented, saw popular opposition during the early 19th century, though not for long. Thus, with the exception of the United States, metrication is now fully or substantially accepted in all countries.>>
How many ages hence shall this our lofty scene be acted over in states unborn and accents yet unknown!
  • - - CASSIUS, Julius Caesar Act 3, Scene 1
http://en.wikipedia.org/wiki/Mars_Climate_Orbiter#Cause_of_failure wrote:

<<The Mars Climate Orbiter (formerly the Mars Surveyor '98 Orbiter) was a 338 kilogram (750 lb) robotic space probe launched by NASA on December 11, 1998 to study the Martian climate, atmosphere, surface changes and to act as the communications relay in the Mars Surveyor '98 program, for Mars Polar Lander. However, on September 23, 1999, communication with the spacecraft was lost as the spacecraft went into orbital insertion.

On November 10, 1999, the Mars Climate Orbiter Mishap Investigation Board released a Phase I report, detailing the suspected issues encountered with the loss of the spacecraft. Previously, on September 8, 1999, Trajectory Correction Maneuver-4 was computed and then executed on September 15, 1999. It was intended to place the spacecraft at an optimal position for an orbital insertion maneuver that would bring the spacecraft around Mars at an altitude of 226 kilometers on September 23, 1999. However, during the week between TCM-4 and the orbital insertion maneuver, the navigation team indicated the altitude may be much lower than intended at 150 to 170 kilometers. Twenty-four hours prior to orbital insertion, calculations placed the orbiter at an altitude of 110 kilometers; 80 kilometers is the minimum altitude that Mars Climate Orbiter was thought to be capable of surviving during this maneuver. Final calculations placed the spacecraft in a trajectory that would have taken the orbiter within 57 kilometers of the surface where the spacecraft likely disintegrated because of atmospheric stresses. The primary cause of this discrepancy was engineering error. Specifically, the flight system software on the Mars Climate Orbiter was written to take thrust instructions using the metric unit newtons (N), while the software on the ground that generated those instructions used the Imperial measure pound-force (lbf). This error has since been known as the metric mixup and has been carefully avoided in all missions since by NASA.

The discrepancy between calculated and measured position, resulting in the discrepancy between desired and actual orbit insertion altitude, had been noticed earlier by at least two navigators, whose concerns were dismissed. A meeting of trajectory software engineers, trajectory software operators (navigators), propulsion engineers, and managers, was convened to consider the possibility of executing TCM-5, which was in the schedule. Attendees of the meeting recall an agreement to conduct TCM-5, but it was ultimately not done.>>

Re: APOD: Lenticular Clouds Over Washington (2012 Nov 04)

Posted: Sun Nov 04, 2012 10:31 pm
by ta152h0
I have seen these on a regular basis from my backyard. I have also seen the Moon right on top of the peak. Since then too many trees have grown in the way.

Re: APOD: Lenticular Clouds Over Washington (2012 Nov 04)

Posted: Sun Nov 04, 2012 11:49 pm
by em53x_B
Could these lenticular cloud formations be caused or influenced by a Von Karman vortex street forming on the leeward side of the mountain?

Re: APOD: Lenticular Clouds Over Washington (2012 Nov 04)

Posted: Mon Nov 05, 2012 1:38 am
by quigley
Okay, boys and girls. The APOD staff does a terrific job of bringing us interesting stuff each and every day. Even if it's a repeat, the marvels portrayed are worth another look. I'm saddened when I see the thread of posts reading like an episode of the Big Bang Theory TV show. Let's keep it civil...k?

Re: APOD: Lenticular Clouds Over Washington (2012 Nov 04)

Posted: Mon Nov 05, 2012 2:18 am
by Beyond
quigley wrote:Okay, boys and girls. The APOD staff does a terrific job of bringing us interesting stuff each and every day. Even if it's a repeat, the marvels portrayed are worth another look. I'm saddened when I see the thread of posts reading like an episode of the Big Bang Theory TV show. Let's keep it civil...k?
I don't watch much TV at all, so i take it that on the show you mentioned, they all gripe-bitch-moan and complain a lot?

Re: APOD: Lenticular Clouds Over Washington (2012 Nov 04)

Posted: Mon Nov 05, 2012 3:12 am
by Canadian Grandma
When I saw today's APOD I thought someone was playing with a photo--with paint or computer. I have never seen a lenticular cloud, nor a picture of one. Fascinating what nature can do. Is it possible such cloud formations have triggered some of the stories of flying saucers?

Re: APOD: Lenticular Clouds Over Washington (2012 Nov 04)

Posted: Mon Nov 05, 2012 3:16 am
by neufer
em53x_B wrote:
Could these lenticular cloud formations be caused or influenced by a Von Karman vortex street forming on the leeward side of the mountain?
No.
Lenticular clouds are stationary and are a consequence of air passing over a mountain.

Von Karman vortex streets are periodic and are a consequence of air passing around a mountain.