Jump to content

Archived

This topic is now archived and is closed to further replies.

Osbourne One-Nil

A Strange Cloud This Morning

Recommended Posts

I saw this whilst taking the kids somewhere this morning. Taken from a moving car by a boy, so apologies about the quality, but it looked a bit weird to me, and I wondered if it was one of those thingies I read about somewhere that happened some place?

post-717-028705200 1288005722_thumb.jpg post-717-054219300 1288005714_thumb.jpg

The above have been enhanced to bring out the detail.Below are untouched shots.

post-717-027153400 1288005985_thumb.jpg post-717-082801000 1288005951_thumb.jpg

Share this post


Link to post
Share on other sites

That's what I meant!

Wiki says they're quite rare, so I assume they're common as muck? Can't say I've seen one before though.

Share this post


Link to post
Share on other sites

Certainly not as common as muck. I've seen a few over the years but then I'm always on the lookout for such things.

Very rarely you'll see one which is an almost perfectly round hole in a large sheet of cloud.

Share this post


Link to post
Share on other sites

Nice pics but are we certain that's a fallstreak hole? It's not that well defined and I was under the impression that they normally formed in Ac or Cc. which isn't the case here.

Share this post


Link to post
Share on other sites

Those aren't real clouds IMO, they're aircraft pollution. Telltale long, straight lines instead of small "mare's tail" shapes and too far from an approaching front to be natural Ci or Cs types. It was everywhere this morning and could be clearly observed changing from a small line into areas of pseudo-cirrus. Anyone who claim's it isn't a serious environmental issue really is deluded- remember those lovely blue skies when that volcano grounded all the planes? It's even producing some kind of precipitation here.

Share this post


Link to post
Share on other sites

come on mate-I rarely say a post is ridiculous but to say contrails then produce precip is a real fairy story.

Of course contrails have increased over the years,how many more flights are there by jet aircraft then used to be the case?

Not another conspiracy theory? Just what is the conspiracy about then?

The contrails you post about seem aligned n-s or no further back than nnw-sse. Which air corridor would that be then?

Have a look at the civil corridors across and up and down the UK, yes there are a few N-s or thereabouts but not many compared to directions different to that. Again remember how many more aircraft fly at altitude compared to 10 let alone 20 or more years ago.

I'd like solid proof please.

Share this post


Link to post
Share on other sites

I'm not into the chemtrails conspiracy theory John, but I'm 99% sure those are not natural clouds. They're from normal passenger jets, and I've watched clouds like that develop from single exhaust trails.

I don't live under a civil air corridor according to the maps I've seen, but nevertheless I see loads of contrails in all parts of the sky, including ones that seem to be performing turns practically overhead. And because the damn things are so high, they can be seen from much further away than most clouds- a common sight is the Manchester contrails on one horizon, the Birmingham ones on another and even those from the path west from Heathrow right on the southern edge of the sky (I've compared what I see with satellite pics a few times, and it seems contrails that are overhead around Gloucester can be seen from Shrewsbury). And I've looked at sequences showing contrails forming out west of Ireland spreading east and covering the Midlands.

It's certainly my impression that contrails, particularly the persistent spreading types, are far more numerous than even 10-15 years ago, and watching them it's clear they substantially reduce sunshine levels in this part of the world (even thickening at times to the point that they have grey undersides and make the sun invisible). I honestly believe that sometime in the near future it will emerge just what havoc they, normal passenger-jet contrails not "chemtrails", are playing with the weather and something (just a guess- children that turn out to lack Vitamin D or crops that won't grow properly because contrails are reducing sunlight) will be proven that will see contrails given the CFC treatment. Just hope it happens sooner rather than later.

Share this post


Link to post
Share on other sites

Contrails can be predicted by using upper air diagrams. Their appearance depends on a mix of humidity, wind and temperature profiles at high levels. They are higher in summer and lower in winter as the upper air temperature changes.

Aside from that where they occur is governed by aircraft flights both civil and military. Most military flights, particularly training flights are a mix of high-low-high as aircraft get to the flight training areas more efficiently at high level. You live near a major training area, Wales and the Marches for low level flights. Thus some of the trails may be from military aircraft which would account for sharp angles appearing at times. Civil aircraft will fly along specified air lanes and any changes they make are less likely to be sharp.

Contrails have increased simply because of the number of flights by aircraft both civil and military over the years.

There has never been any real evidence by those who believe in the chemtrail idea.

Quite often contrails are an indicator that the upper air is changing thus allowing trails to form. Often after their appearance Ci Cc and Cs are likely to be seen as well. That is even though contrails will normally occur at higher levels than the Cirrus type clouds.

Hope that helps.

Share this post


Link to post
Share on other sites

In the pdf below is the promised explanation of how it is possible to forecast when and where contrails will for. Will they be non persistent or persistent.

Contrails and forecasting them.pdf

I should have added my thanks to Uni of Wyoming and Dundee Uni

both some time ago gave permission for me to use their products in a tutorial type situation.

Share this post


Link to post
Share on other sites

So, was it a fallstreak hole then?

Not in my opinion for what it's worth.:)

Share this post


Link to post
Share on other sites

Contrails can be predicted by using upper air diagrams. Their appearance depends on a mix of humidity, wind and temperature profiles at high levels. They are higher in summer and lower in winter as the upper air temperature changes.

Aside from that where they occur is governed by aircraft flights both civil and military. Most military flights, particularly training flights are a mix of high-low-high as aircraft get to the flight training areas more efficiently at high level. You live near a major training area, Wales and the Marches for low level flights. Thus some of the trails may be from military aircraft which would account for sharp angles appearing at times. Civil aircraft will fly along specified air lanes and any changes they make are less likely to be sharp.

Contrails have increased simply because of the number of flights by aircraft both civil and military over the years.

There has never been any real evidence by those who believe in the chemtrail idea.

Quite often contrails are an indicator that the upper air is changing thus allowing trails to form. Often after their appearance Ci Cc and Cs are likely to be seen as well. That is even though contrails will normally occur at higher levels than the Cirrus type clouds.

Hope that helps.

Most of the ones nearly overhead are definitely commercial- Boeings or something similar, I've pointed binoculars at them on occasion. Anyway, I would have thought the military would be all for eliminating contrails, since it would make their planes a lot harder to spot and track, not to mention giving them better air-ground visibility when they're flying at stratospheric levels.

Since it's possible to forecast when they will form and persist, the obvious answer is to prevent planes flying through parcels of air conducive to trail formation. I remember reading somewhere that flying a few thousand feet lower would reduce contrails by over 75%. However, yesterday morning I saw planes making what I call "grey contrails"- they look and spread just like the well-known white ones, but appear grey like Altostratus and seem to be forming at lower altitudes. It's just a scandal IMO that the authorities can prevent road vehicles from operating if they don't meet strict standards on exhaust emissions (having already taken action to eliminate the London smogs of old), but allow aircraft to block out more and more sunlight, which is after all essential for life on Earth, with goodness knows what implications for the planet's weather.

Share this post


Link to post
Share on other sites

Most of the ones nearly overhead are definitely commercial- Boeings or something similar, I've pointed binoculars at them on occasion. Anyway, I would have thought the military would be all for eliminating contrails, since it would make their planes a lot harder to spot and track, not to mention giving them better air-ground visibility when they're flying at stratospheric levels.

Since it's possible to forecast when they will form and persist, the obvious answer is to prevent planes flying through parcels of air conducive to trail formation. I remember reading somewhere that flying a few thousand feet lower would reduce contrails by over 75%. However, yesterday morning I saw planes making what I call "grey contrails"- they look and spread just like the well-known white ones, but appear grey like Altostratus and seem to be forming at lower altitudes. It's just a scandal IMO that the authorities can prevent road vehicles from operating if they don't meet strict standards on exhaust emissions (having already taken action to eliminate the London smogs of old), but allow aircraft to block out more and more sunlight, which is after all essential for life on Earth, with goodness knows what implications for the planet's weather.

I'll try and answer some of your points

re the military I have posted that they fly high level to their low level training areas of which one is close by you to your west, the Marches and especially Wales. Much of the military training goes into combat flying at very low level; in the UK they are restricted to training in all but, I think 3 very specific areas, to not below 200 above ground level, so no contrails from them.

re the comment about preventing planes flying through areas where contrails are forecast. Have you any idea how on earth the relevant air traffic control centres would be able to change hundreds of flights from say, 39000ft to 35000ft or whatever level. I would recommend you read a fairly general book on how civil aircraft are moved from one place to another that would help you realise its nothing like as simple as you suggest.

As a retired professional meteorologist I would hazard a guess that the amount of sunlight they prevent is a very small %, way below 5%, and is I suppose one penalty we all have to pay for our overall standard of living?

No doubt you buy vegetables and fruit grown thousands of miles away for one example?

Do you not go abroad on your holidays by air?

I'm not getting at you just trying to show that changing things any of us do not agree with is much more complex than we often imagine.

Share this post


Link to post
Share on other sites

What ever they are still great photos :)

Share this post


Link to post
Share on other sites

I'll try and answer some of your points

re the comment about preventing planes flying through areas where contrails are forecast. Have you any idea how on earth the relevant air traffic control centres would be able to change hundreds of flights from say, 39000ft to 35000ft or whatever level. I would recommend you read a fairly general book on how civil aircraft are moved from one place to another that would help you realise its nothing like as simple as you suggest.

As a retired professional meteorologist I would hazard a guess that the amount of sunlight they prevent is a very small %, way below 5%, and is I suppose one penalty we all have to pay for our overall standard of living?

No doubt you buy vegetables and fruit grown thousands of miles away for one example?

Do you not go abroad on your holidays by air?

I'm not getting at you just trying to show that changing things any of us do not agree with is much more complex than we often imagine.

I don't doubt that rerouting all those flights would be challenging, but surely it's time for dialogue between airlines, meteoroligists, government and the general public on this issue. But I have to say that I believe it's way more than 5% of sunlight they are blocking, for the following reasons:

*During the air shutdown in April I didn't see a single Ci or Cs type cloud for the entire time the planes were grounded. But within hours of the flights starting there were huge streaks and layers of milky white cloud everywhere, which noticeably dimmed the sun. Additionally on the Monday (19th) the forecast was for North Sea low cloud to come in overnight, and likely persist all day. Come in overnight it did, but it had gone by 11am. In April. With aircraft it often persists well past midday near the summer solstice. I believe the lack of aircraft enabled the sun to burn it off more rapidly, so we got more sunlight as an indirect result of not having aircraft up there.

*http://contrailscience.com/volcano-clears-the-skies-of-contrails/ These two satellite pictures, on the 10th and 17th. For all the guessing about what the picture(s) on the right would have looked like with aircraft, the fact remains that here we were robbed of at least 8 hours of bright sunshine on Saturday 10th. I remember the day well- the forecast was for a clear day, and we got masses and masses of aircraft-induced clouds that were so thick they made the sun's disk invisible for much of the day. The 17th, on the other hand, was the clearest day I can remember in recent years, and what's more, the sunshine felt a lot stronger than normal. We get, at a conservative guess, 15-20 days per year like April 10th and probably over 100 where 1 hour or more of sunshine is denied us because of aircraft-induced clouds. So thats a bare minimum 220-odd hours of sunshine gone per year, probably more like 300. 15-20% of the annual average.

*Chemtrails may be a conspiracy theory, but "global dimming" is real. It's been measured. I remember when it first hit the news they concentrated on industrial pollution, and only mentioned aircraft in passing. They mentioned that the dimming seemed to reverse in the 1990s as all the laws on pollution at ground level took effect, but I believe that the increase in aircraft has now wiped that out.

*Nowhere has it been considered that aircraft pollution has altered weather patterns on a large, even global scale. I'll set the ball rolling: the mid-latitude jetstream across the

Atlantic has behaved oddly in recent years to say the least. It just doesn't seem to shift as far north in summer allowing the Azores high to extend over Britain. And its route coincides with some of the busiest air routes in the world. One dull, wet summer is due to natural variation. 4 in a row and something's amiss. Yes I know there were lots of pretty bad summers in past decades but to have months as wet as May-July 07 and July 2009, and as dull as August 2008 and July 2010 in such close proximity isn't normal. The sudden change in summers after 2006 was one of the most striking changes in weather patterns I remember (along with the sudden warming of winters from 1988/9); was this the moment the tipping point was reached? (They attributed the African famines of the 70s/80s to dimming not allowing the rainbelts to move north).

I do buy those vegetables on occasion but only because there's no choice most of the time. But strawberries for Christmas and roast parsnips on July afternoons, no thanks. If eating seasonally is a consequence of grounding aircraft, that's fine by me. As is waiting till the planes carrying exotic fruit can make their way here without passing through contrail-friendly air. More sunshine would make growing things here easier anyway. Yes I have travelled by air in the past, but after experiencing those Eyjafjallajokull skies I would be more than willing to look at alternatives in future, especially if there is a worldwide effort to make them more affordable. Apart from giving us a glimpse of the kind of skies our forebears enjoyed, the other thing Eyjafjallajokull reminded us of was that we live on an island. And that Spain is a long way away.

Share this post


Link to post
Share on other sites

*Chemtrails may be a conspiracy theory, but "global dimming" is real. It's been measured. I remember when it first hit the news they concentrated on industrial pollution, and only mentioned aircraft in passing. They mentioned that the dimming seemed to reverse in the 1990s as all the laws on pollution at ground level took effect, but I believe that the increase in aircraft has now wiped that out.

I don't think anyone is arguing that global dimming, or to be more precise the currently occurring, widespread and significant reduction in global irradiance is not important. It is true that in the early days of measuring global irradiance aircraft played a lesser role but that was because air traffic was much lighter then. Who are they (they keep cropping up) that mention the reversal of dimming in the 1990s? I ask because a review of the published information on secular changes in irradiance up to 2000 concluded that globally the decrease averaged 2.7% per decade and now totals 20Wm-2 . This is a very complicated subject and obviously aircraft, and for that matter cars, play a role, but I don't believe the 5% figure for a second unless you have some evidence to back up the statement.

An extract from an article Global Dimming-A new aspect of climate change by G. Stanhill. (Weather Jan. 2005 Vol. 60. No. 1

"The diurnal temperature range (DTR) is closely linked with , and is often used as a proxy measure for calculating global radiation (Bristow and Campbell 1984; Thornton and Running 1999). The physical basis for this linkage is that part of the solar energy absorbed at the earth's surface is convected into the lower atmosphere where it raises the daytime maximum temperature above the night-time minimum. A second factor which controls DTR is the degree of surface wetness which determines the partitioning of solar heating between convective and latent heat fluxes; DTR is greatest at non evaporating desert sites and least at ocean island sites. This effect of surface wetness has been allowed for by including a rainfall term in the equations used to calculate irradiance from DTR"

A striking example of a wide-scale, man induced change in DTR was provided by the 11 September terrorist attacks in New York and Washington when commercial air traffic in the USA was grounded for three days. During this period DTR was 1.8 degC above climatological normal, almost certainly as a result in the observed reduction in contrail trail-induced cirrus cloud cover which presumably led to an increase in irradiance, (Travis et 01. 2002). Another man-made climate change experiment occurs each year in Israel on the Day of Atonement when road traffic ceases. Measurements between 1965 and 2003 at the Israel Meteorological Services Observatory at Bet Dagan, close to two major traffic interchanges, show that DTR increased by an average of 0.3 degC while irradiance, increased by an average of 9.72Wm-2 as compared with the values measured seven days before and after the fast day".

I will leave your comments on changing weather patterns to higher authority except to say the ubiquitous they have cropped up again! (They attributed the African famines of the 70s/80s to dimming not allowing the rainbelts to move north).

Share this post


Link to post
Share on other sites

your comments about Ci or Cs type clouds are in error as contrails are neither of them and, as I tried to point out, are quite often higher than Ci Cs clouds.

The presence of contrails along with Ci Cs simply indicates the temperature and to a lesser extent the humidity, at least for contrails. Both tend to indicate the likely arrival of frontal cloud or an upper trough. Contrails being usually higher will be present before the Ci type clouds.

The idea that the St did not clear because of contrails is interesting but I doubt with any actual fact in it. That on another occasion when the forecast was wrong showed it was contrail lacking that caused it is, as a retired senior forecaster is a non starter. The forecast was wong-full stop nothing to do with the presence or absence of contrails. I quite often post comments about trying to predict when St or Sc type cloud will roll in off the N Sea. Equally trying to predict when it will burn back is just as difficult these days as prior to both large numbers of civil aircraft or computer models which are no more accurate for St Sc changes than basic forecasting 30-40 years ago.

I respect your views about your food and holidays-no problem with that.

Share this post


Link to post
Share on other sites

Something I should have added to last post.but forgot. Global dimming poses a problem to the current consensus explanation of global warming - how can a significant decrease in solar heating of the earh's surface be reconciled with an increase in its surface temperature? Does it centre around the magnitude of aerosol-induced short wave cooling, or, putting it another way, negative radiative forcing? Oh well, something else to add to the mix.

Share this post


Link to post
Share on other sites

So, was it a fallstreak hole then?

Funny coz when I first read that word I had to read it twice again before I could get the word "fail-steak" out of my head :lol:

Share this post


Link to post
Share on other sites

Surprised this never came up during the discourse.

A bank of clouds off North America’s west coast featured a series of white trails in early October 2009. The Moderate Resolution Imaging Spectroradiometer (Modis) on NASA’s Terra satellite captured this true-color image on October 5, 2009. Although the white trails look vaguely like contrails left behind by airplanes, they actually result from ship exhaust.

The exhaust trails’ appearance—whiter than those of the surrounding clouds—results from them having smaller, but more numerous cloud droplets. Compared to the surrounding air, ship exhaust contains more particles, and each particle can act as a nucleus around which water vapor condenses. Because the available water is divided up among a greater number of particles, the resulting ship tracks consist of cloud particles that are smaller and more abundant than those of the surrounding clouds.

The cloud bank shows a fairly sharp boundary along its eastern edge, and the ship tracks end with the other clouds. The cloud-free area to the east apparently holds drier air, which lacks sufficient moisture to lead to cloud formation.

pactracks_tmo_2009278_lrg.jpg

Credit: NASA http://earthobservatory.nasa.gov/

Share this post


Link to post
Share on other sites

×
×
  • Create New...