Ice meteors, climate, sceptics

Brian Harmer wrote:
On 21 Jan 2004 20:12:43 GMT, Brian Sandle
wrote:

What is the largest block of ice that can form on a plane?


And where on the airframe does it form? A block of ice of the
magnitude shown on TV would not improve the flying qualities of a wing
... I assume that any such block could not be formed except near some
outlet on the fuselage or at a junction between the fuselage and a
flying surface.

Yes, well I always wondered whether these meteors should be on the
meteorology newsgroup. Maybe pilots would know know more about it.

Are there any condensation outlets on planes which form 5kg icicles near
them? Maybe some formation flyers would have seen them. When do they drop
off?

Gib Bogle wrote:

The suggestion I saw was that it fell from a wing, not from a toilet.

If these large blocks formed on wings they would affect the aerodynamics
wouldn't they?

The physics involved in a massive block forming in a clear sky through
natural causes is so mind-boggling as to be virtually inconceivable.
Probably ice meteor incidence is correlated with aircraft traffic.

A normal tiny meteor can act as a nucleus for ice to form.

Meteors are heated by the heat from the air they compress in front of
them. Some of their surface melts off, but once they get into the denser
atmosphere they can be going rather slow take quite a while to land and
get cooled by the cold air.

There is nothing suspicious about water vapour in clear sky weather. Ever
noticed dew in clear weather? As the air cools in the evening it becomes
able to hold less water vapour. A supersaturated condition forms and water
is deposited on the nearest object available. Quite a lot of dew can be
formed in a few minuters when the dew point is reached. Same thing with
water being heated to 100 degrees Celsius in a smooth vessel. Then if
something rough is put in the steam is allowed to form and it may boil
over.

Where are the data about upper atmosphere temperature and global warming?

Brian Sandle wrote:

The physics involved in a massive block forming in a clear sky through
natural causes is so mind-boggling as to be virtually inconceivable.
Probably ice meteor incidence is correlated with aircraft traffic.


A normal tiny meteor can act as a nucleus for ice to form.


You could calculate the time it takes to grow a 10kg chunk of ice under
the most extreme plausible conditions of atmospheric supersaturation.
See ch. 4 of Wallace and Hobbs.

But it would be a pointless exercise, because the answer would be
measured in weeks or months, and you could never hope to keep your chunk
of ice suspended in the atmosphere longer than a few minutes, once you
got past a few grams.

And you wouldn't get a clear chunk of ice anyway by this mechanism;
you'd get a big porous mass of ice crystals.


Where are the data about upper atmosphere temperature and global warming?

Here's a factoid that might help put things into perspective: typical
water vapor concentrations in the upper atmosphere are below 4 parts per
million, relative to air. And air at, say, 50 km altitude has a density
on the order of 1 gram per cubic meter. So to grow a 10 kg chunk of ice
at that altitude would require you to figure out a way to quickly
condense onto one object *all* of the water vapor in 2.5 cubic
*kilometers* of ambient air.

Bottom line: I tend to think the stories about chunks of ice out of the
clear sky, while possibly true in some sense, have nothing to do with
meteorology in any form, let alone global warming.

Could someone be deliberately tossing junks of ice out of passing
aircraft? Recall the crop circle "mystery" -- it eventually was
acknowledged to be a hoax -- by the hoaxers themselves - after countless
"experts" had been quoted as saying, "it can't be a hoax."

Grant wrote:
Brian Sandle wrote:

The physics involved in a massive block forming in a clear sky through
natural causes is so mind-boggling as to be virtually inconceivable.
Probably ice meteor incidence is correlated with aircraft traffic.


A normal tiny meteor can act as a nucleus for ice to form.


You could calculate the time it takes to grow a 10kg chunk of ice under
the most extreme plausible conditions of atmospheric supersaturation.
See ch. 4 of Wallace and Hobbs.

But it would be a pointless exercise, because the answer would be
measured in weeks or months, and you could never hope to keep your chunk
of ice suspended in the atmosphere longer than a few minutes, once you
got past a few grams.

Unless there is some sort of vortex.

And you wouldn't get a clear chunk of ice anyway by this mechanism;
you'd get a big porous mass of ice crystals.

Like hoar frost? It's incredibly patterened, but quite solid, not porous, I
think.

Where are the data about upper atmosphere temperature and global warming?

Here's a factoid that might help put things into perspective: typical
water vapor concentrations in the upper atmosphere are below 4 parts per
million, relative to air. And air at, say, 50 km altitude has a density
on the order of 1 gram per cubic meter. So to grow a 10 kg chunk of ice
at that altitude would require you to figure out a way to quickly
condense onto one object *all* of the water vapor in 2.5 cubic
*kilometers* of ambient air.

Any reason for 50 km? Most of the air where vortices could do anything is in
the troposphere.

Bottom line: I tend to think the stories about chunks of ice out of the
clear sky, while possibly true in some sense, have nothing to do with
meteorology in any form, let alone global warming.

Could someone be deliberately tossing junks of ice out of passing
aircraft?

I have heard of frogs raining down. Seemed genuine.


Recall the crop circle "mystery" -- it eventually was
acknowledged to be a hoax -- by the hoaxers themselves - after countless
"experts" had been quoted as saying, "it can't be a hoax."

Ha ha, yes. It became quite a hobby of the `sceptics' or pranksters to show
how it could be done. How did they hoax the real crop circles in which the
bent over wheat is said to keep growing - it is not trampled? Enlightenment
please.


(Though I think this example, from the shape of the block has been formed in
some sort of mold. Either that or cleaved off somehow.)

Brian Sandle wrote:


Unless there is some sort of vortex.



not sure how a vortex would affect my arguments


And you wouldn't get a clear chunk of ice anyway by this mechanism;
you'd get a big porous mass of ice crystals.


Like hoar frost? It's incredibly patterened, but quite solid, not porous, I
think.


"Feathery" is the word that came to mind the last time I examined thick
hoarfrost. Porous in the sense that you have needle-like or dendritic
crystals growing into a feathery mass, as opposed to a uniform glaze of
ice. Note by the way that hoar froast, which grows by sublimation from
the vapor phase, is different than rime ice, which is less porous. The
latter involves the accretion of supercooled droplets and requires a
visible cloud. It's the same process involved in hail and graupel
formation, whereas hoar frost is more analogous the formation of snow.

Where are the data about upper atmosphere temperature and global warming?


Here's a factoid that might help put things into perspective: typical
water vapor concentrations in the upper atmosphere are below 4 parts per
million, relative to air. And air at, say, 50 km altitude has a density
on the order of 1 gram per cubic meter. So to grow a 10 kg chunk of ice
at that altitude would require you to figure out a way to quickly
condense onto one object *all* of the water vapor in 2.5 cubic
*kilometers* of ambient air.


Any reason for 50 km? Most of the air where vortices could do anything is in
the troposphere.

If tropospheric vortices are involved in producing large chunks of ice,
then they're also producing clouds. I thought the issue at hand was one
of ice chunks falling out of the clear blue sky, and more specifically
out of the stratosphere. But maybe I haven't been reading closely enough.


Bottom line: I tend to think the stories about chunks of ice out of the
clear sky, while possibly true in some sense, have nothing to do with
meteorology in any form, let alone global warming.


Could someone be deliberately tossing junks of ice out of passing
aircraft?


I have heard of frogs raining down. Seemed genuine.


I think the prevailing view on that is that the frogs were probably
swept up into the air by a tornado or waterspout. Although I have to
admit that most such accounts have aspects that are hard to explain, IF
you take them at face value.


Recall the crop circle "mystery" -- it eventually was

acknowledged to be a hoax -- by the hoaxers themselves - after countless
"experts" had been quoted as saying, "it can't be a hoax."


Ha ha, yes. It became quite a hobby of the `sceptics' or pranksters to show
how it could be done. How did they hoax the real crop circles in which the
bent over wheat is said to keep growing - it is not trampled? Enlightenment
please.

That's precisely one of the arguments the "experts" used. And then the
hoaxers showed that it's really not that hard to bend the stems without
breaking them.

Grant wrote:
Brian Sandle wrote:


Unless there is some sort of vortex.



not sure how a vortex would affect my arguments


And you wouldn't get a clear chunk of ice anyway by this mechanism;
you'd get a big porous mass of ice crystals.


Like hoar frost? It's incredibly patterened, but quite solid, not porous, I
think.


"Feathery" is the word that came to mind the last time I examined thick
hoarfrost.

Though `feathery' gives the impression that it would be easy to break. But
it is soldily attached to whatever it grows on.

Porous in the sense that you have needle-like or dendritic
crystals growing into a feathery mass, as opposed to a uniform glaze of
ice.

Though not crushable as I have seen it, there were not filaments
projecting into the air.

Note by the way that hoar froast, which grows by sublimation from
the vapor phase, is different than rime ice, which is less porous. The
latter involves the accretion of supercooled droplets and requires a
visible cloud. It's the same process involved in hail and graupel
formation, whereas hoar frost is more analogous the formation of snow.

What I saw was a tremendous pattern on a car roof top where there had been
very slight air movement.

Where are the data about upper atmosphere temperature and global warming?


Here's a factoid that might help put things into perspective: typical
water vapor concentrations in the upper atmosphere are below 4 parts per
million, relative to air. And air at, say, 50 km altitude has a density
on the order of 1 gram per cubic meter. So to grow a 10 kg chunk of ice
at that altitude would require you to figure out a way to quickly
condense onto one object *all* of the water vapor in 2.5 cubic
*kilometers* of ambient air.


Any reason for 50 km? Most of the air where vortices could do anything is in
the troposphere.

If tropospheric vortices are involved in producing large chunks of ice,
then they're also producing clouds. I thought the issue at hand was one
of ice chunks falling out of the clear blue sky, and more specifically
out of the stratosphere. But maybe I haven't been reading closely enough.

I don't think the original article mentioned stratoshpere, though I guess
that is the part of the atmosphere which would be cooling under global
warming? Your argument about the amount of water vapour there is quite
convincing. However what about clouds that form at 50km over the polar
regions?


Bottom line: I tend to think the stories about chunks of ice out of the
clear sky, while possibly true in some sense, have nothing to do with
meteorology in any form, let alone global warming.


Could someone be deliberately tossing junks of ice out of passing
aircraft?


I have heard of frogs raining down. Seemed genuine.


I think the prevailing view on that is that the frogs were probably
swept up into the air by a tornado or waterspout.

Yes. How far could they be thrown?

Although I have to
admit that most such accounts have aspects that are hard to explain, IF
you take them at face value.


Recall the crop circle "mystery" -- it eventually was

acknowledged to be a hoax -- by the hoaxers themselves - after countless
"experts" had been quoted as saying, "it can't be a hoax."


Ha ha, yes. It became quite a hobby of the `sceptics' or pranksters to show
how it could be done. How did they hoax the real crop circles in which the
bent over wheat is said to keep growing - it is not trampled? Enlightenment
please.

That's precisely one of the arguments the "experts" used. And then the
hoaxers showed that it's really not that hard to bend the stems without
breaking them.

Do you a ref? It seems the bend looks more like the sort in a plant which
has been grown in a pot then turned on its side. Though I cannot verify
that except pass the ref, which also gives they are produced very rapidly,
and the confusion engendered by "sceptics"' film arrangements.


Linkname: Discovery Channel Crop Circles
URL: http://www.oregonuforeview.com/discchancrop.html
Last Mod: Tue, 14 Aug 2001 02:22:04 GMT
size: 122 lines

Brian Sandle wrote:

Recall the crop circle "mystery" -- it eventually was
acknowledged to be a hoax -- by the hoaxers themselves - after
countless "experts" had been quoted as saying, "it can't be a hoax."

Ha ha, yes. It became quite a hobby of the `sceptics' or pranksters
to show how it could be done. How did they hoax the real crop circles
in which the bent over wheat is said to keep growing - it is not
trampled? Enlightenment please.

The same way the %#&$ lawn keeps growing no matter how many "mow rows"
you apply to it? =)

The crop circle crowd seem to be awfully good at looking at something
not all that overly impressive and instantly deciding it was humanly
impossible. Others might call this "wishful thinking" or "delusion" -
kinda like the "Rods" scam from a few years back.

"Bob Harrington" wrote in message news:yW%Pb.103902$5V2.398094@attbi_s53...
Brian Sandle wrote:
Recall the crop circle "mystery" -- it eventually was
acknowledged to be a hoax -- by the hoaxers themselves - after
countless "experts" had been quoted as saying, "it can't be a hoax."

Ha ha, yes. It became quite a hobby of the `sceptics' or pranksters
to show how it could be done. How did they hoax the real crop circles
in which the bent over wheat is said to keep growing - it is not
trampled? Enlightenment please.

The same way the %#&$ lawn keeps growing no matter how many "mow rows"
you apply to it? =)

The crop circle crowd seem to be awfully good at looking at something
not all that overly impressive and instantly deciding it was humanly
impossible. Others might call this "wishful thinking" or "delusion" -
kinda like the "Rods" scam from a few years back.

Sorry to drop in out of lurking, but I always found it amusing to
watch ET cropcircle proponents squirm when I pointed out at
sci.skeptic that;

During the foot and mouth disease outbreak in the UK in 2001 the
government closed all countryside footpaths, effectively blocking any
but the farmer from crop fields.

During the ban no crop circles were recorded in the English
countryside.

The first crop circle in England to be recorded was the day after the
walking ban was lifted in that county.

Very community minded is our ET.

--
Eric Hocking
www.twofromoz.freeserve.co.uk
"A closed mouth gathers no feet"
"Ignorance is a renewable resource" P.J.O'Rourke