I'm going to take a risk and continue an OT thread here, because it IS full
moon, after all...
That's a great lenticular cloud picture! The sunrise alpenglow lights up
the bottoms of the clouds quite nicely.
It is, however, a picture of Mt. Rainier. However, Mt. St. Helens isn't far
away. Also, as seen from the WNW like this, Mt. Rainier shows its three
sub-summits rather well, and it's reminiscent of the truncated, blasted-out
cone of St. Helens. In this photo, the three high points that we see are,
from left to right, Liberty Cap, Columbia Crest, and Point Success. The
middle one, Columbia Crest, is the highest point on the mountain, at
14,410' a.s.l. The main triangular face that we see, leading up to Liberty
Cap, is called the Mowich Face. Part of the Tahoma Glacier, the biggest
glacier on the west side of the mountain, is visible extending down and to
the right of the saddle between Liberty Cap and Point Success. It's hard to
pick out individual glaciers in photos taken in the winter, however,
because of all the seasonal snow on the mountain.
The Cascade volcanoes are great places to see lenticular clouds. They form
above Mt. Rainier all the time. Sometimes they stack up three and four
deep. Phil is absolutely right about there being high winds associated with
them. These 'cloud caps', as they're called locally, form on the windward
side of the summit and dissipate on the leeward side. A cloud cap on the
mountain is a sure sign of high wind. I've summitted Rainier in cloud caps,
and it's wind city. Even when a cap has recently cleared off, you're likely
to get smacked around by the wind pretty good. Sometimes one can stagger on
to the summit coated in rime ice that has built up on your clothing and
gear as you climbed through the cloud cap.
We get some nice lenticulars down here in California, too. Mt. Shasta gets
'em fairly often, and sometimes they're seen over the eastern Sierra (e.g.
the Owens Valley), where they're called the 'Sierra Wave'. When I was down
in New Zealand, the lenticular clouds over the Southern Alps were called
'hogsbacks'.
When I finally got up Shasta, it was on a windy day, with a cloud cap
coming and going. Being near the summits of these peaks in such conditions
is wild - these web-like cloud structures are zooming past, forming and
dissipating before your eyes, and the wind is roaring around you. It's a
good way to feel real small real quick.
I haven't updated my Earthlink site in years, but it looks like at least
some of it is still working. I have some Rainier photos on this page:
http://home.earthlink.net/~marekc/rainier_1.htm
The first one was taken in high wind, although you can't tell it, because
the cloud cap had just cleared off. My friend Craig and I could hardly
stand still for the photo, however because of the way the wind was blowing.
I have a picture of a triple-decker lenticular cloud in the Death Valley
region on this page - sorry it isn't a bigger image:
http://home.earthlink.net/~marekc/panamint3.htm
Hmm, let's see... I've droned on about totally non-astro stuff... is there
some way I can make this post astro-related.... hmmm...
Actually, I've wondered what the observing conditions would be like in a
place like the Owens Valley. I love the Eastern Sierra / Death Valley
region, and I've often fantasized about retiring to some place like Bishop
or Mammoth Lakes. In my fantasy, I have a nice observatory with a roll-off
roof and various large scopes inside. However, I've often wondered about
the seeing in those sorts of rainshadow areas, on the lee sides of mountain
ranges. Would the air coming over the mountains be too turbulent? Would it
cause mixing of air masses of different temperatures, thus leading to bad
seeing? This is an interesting question, and I'll bet that it's more
complex than just guessing that the seeing must be bad. I'd be curious to
test it out sometime.
Marek
Received on Sat Apr 23 11:00:18 2005