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Results of large-eddy simulations of the development of young persistent ice contrails are presented, concentrating on the interactions between the aircraft wake dynamics and the ice cloud evolution over ages from a few seconds to ;30 min. The 3D unsteady evolution of the dispersing engine exhausts, trailing vortex pair interaction and breakup, and subsequent Brunt–Va¨isa¨la¨ oscillations of the older wake plume are modeled in detail in high-resolution simulations, coupled with a bulk microphysics model for the contrail ice development. The simulations confirm that the early wake dynamics can have a strong influence on the properties of persistent contrails even at late times. The vortex dynamics are the primary determinant of the vertical extent of the contrail (until precipitation becomes significant); and this together with the local wind shear largely determines the horizontal extent. The ice density, ice crystal number density, and a conserved exhaust tracer all develop and disperse in different fashions from each other. The total ice crystal number can be significantly reduced due to adiabatic compression resulting from the downward motion of the vortex system, even for ambient conditions that are substantially supersaturated with respect to ice. The fraction of the initial ice crystals surviving, their spatial distribution, and the ice mass distribution are all sensitive to the aircraft type, ambient humidity, assumed initial ice crystal number, and ambient turbulence conditions. There is a significant range of conditions for which a smaller transport such as a B737 produces as significant a persistent contrail as a larger transport such as a B747, even though the latter consumes almost five times as much fuel. The difficulties involved in trying to minimize persistent contrail production are discussed.
Jet- and vortex-regime evolution of contrails behind cruising aircraft is investigated by focusing on the role of aircraft type. Cross-section measurements by ground-based lidar and observational analysis are combined with numerical simulations of fluid dynamics and microphysics in the wake of a two-engine aircraft. Depending on ambient humidity levels, contrail evolution behind short-/medium-range twin-turbofan airliners is classified into two scenarios, which is in contrast to the three scenarios observed for a wide-body four-turbofan aircraft. In the case of ice-subsaturated ambient air, a short visible contrail is formed behind a two-engine aircraft that disappears before the ice is fully entrained into the wingtip vortices (in most cases ≈4 s behind aircraft). The early evaporation of the ice is mainly due to the fast initial jet expansion, mixing the exhaust with the ambient air. Contrails behind a wide-body four-engine aircraft always survive at least until vortex breakdown (i.e., typically 2 min behind aircraft). This is simply due to the larger ice mass in the contrail because of the higher fuel flow rate. Generally, in the case of ice supersaturation, a diffuse secondary wake evolves above the primary vortex wake. For a two-engine aircraft, always the whole contrail persists, while for a four-engine aircraft, the ice inside the primary wake disappears in most cases after vortex breakdown, when the relative humidity is only slightly above ice saturation. In the more rare cases of higher ice-supersaturation the ice in the primary wake survives vortex breakdown and becomes part of the persistent contrail. © 2001 American Geophysical Union
Abstract
A system of multiple continuous-flow condensation nuclei counters (CNC) was assembled, calibrated, and demonstrated on a NASA T-39 Sabreliner jet aircraft. The mission was to penetrate the exhaust plumes and/or contrails of other subsonic jet aircraft and determine the concentrations of submicrometer diameter aerosol particles. Mission criteria required rapid response measurements ( 1 s) at aircraft cruise altitudes (9–12 km). The CNC sampling system was optimized to operate at 160 Torr. Aerosol samples were acquired through an externally mounted probe. Installed downstream of the probe was a critical flow orifice that provided sample to the CNC system. The orifice not only controlled volumetric flow rate, but also dampened probe pressure/flow oscillations encountered in the turbulent aircraft-wake vortex environment. Laboratory calibrations with NaCl particles under representative conditions are reported that indicate small amounts of particle loss and a maximum measurement efficiency of 75% for particles with diameters ranging from 0.01− 0.18 μm Data from exhaust/contrail samplings of a NASA B757 and DC-8 at cruise altitude are discussed. Data include exhaust/contrail measurements made during periods in which the B757 port jet engine burned low-sulfur fuel while the starboard engine simultaneously burned specially prepared high-sulfur fuel. The data discussed highlight the CNC systems performance, and introduce new observations pertinent to the behavior of sulfur in aircraft exhaust aerosol chemistry.
Originally posted by PisTonZOR
I Don't have any pictures of lingering Contrails after a B-17 has left. However, I have shown you a picture of very long Contrails, which look like what you call Chemtrails. If they wern't fine.
Them pictures I linked you to obviously had lasted for much longer than 30 seconds.
Many aircraft also fly the same route, this can produce layers and layers and layers of lingering contrails which may appear to be strange. Wind can blow these 10 minute old contrails sideways. Then a new jet will pass over the same route as the old jet. This pattern of events produces these:
Federal bureaucracies have gotten thousands of phone calls, e-mails and letters in recent years from people demanding to know what is being sprayed and why. Some of the missives are threatening.
It's impossible to tell how many supporters these ideas have attracted, but the people who believe them say they're tired of getting the brush-off from officials. And they're tired of health problems they blame on "spraying."
www.usatoday.com...
Based on my knowledge that the plane wasn't built with Chemspraying equipment and that 777 hasn't gone through any C or D checks which would be required to install something large, such as Chemspraying equipment.
A and B checks are overnight, far to short to add a bunch of tanks to an aircraft then test them.
I don't know who told me about it, but someone did. I beleive it was in another thread when someone showed me that picture of the KLM 777. They suggested that there must be holes in the wings which spray chemicals.
No. But it does mean that Boeing has thousands of people who have an acute understanding of jets.
The few thousand people who work at KPAE and KBFI would most likely know.
Maybe. But the GE-90 is civilian and has no link to defence industries. Also what about RR and PW?
Boeing is far from bankruptcy. There revenue went up $54.845 billion USD last year. This year and last year are both amazing years for Boeing.
Maybe because the FAA is heavily involved in the certification process of all Commercial Airliners.
hey know EVERYTHING about jets and in certification they test ALL parts. They also know what airlines do to maintain them, and what, if any, modifications have taken place
Because KLM 777s land at public airports. MX (maintenance) also aren't just working conformist ants.
Most are heavily interested in jets, and if they discovered strange tanks on jets the whole world would know about it.
How am I deluded? I have never said anything disrespectful here. If I have, point me to it and I will not do it again.
I am not denying what others think is real. I am saying Chemtrails aren't true in reality, not what they beleive in isn't true.
Also what lengths am I going to? Sorry, but you're accusing me being deluded and disrespectful. That's a far greater lengths than doing what I'm doing (Proving a bunch of points wrong).
I will explain them. Give me a moment, we are having blackouts so I will just click post so this won''t be lost.
Originally posted by PisTonZOR
Pilots are constantly monitoring the plane, or scanning for other aircraft.
Also, when on dense airroutes you really have to watch yourself to make sure you aren't on a collision course with another plane.
Although I don't fly Boeing 747's. I have taken control and flown light aircraft into huge airshows. Light aircraft don't usually have TCAS, so you REALLY need to watch where you are.
Watch this: www.flightlevel350.com...
Now all you need is another 747 to be on a collision course, then it's possible for another Uberlingen to happen. Around 50 school gifted children died in that accident. To not scan for other plane sis just plain stupid.
The Uberlingen crash was Europe's third fatal accident in three years caused by errors in air traffic control. It followed collisions on the ground at Paris's Charles de Gaulle airport in 2000 and Milan's Linate airfield in 2001. The sequence ended a 16-year run without any deaths.
Eurocontrol admits it is concerned about the trend. Mr Aguado said: "It worries us a lot when we see two accidents on runways in successive years and a mid-air collision - which is something which Europe has not experienced for many years."
It is working on a new system which will give controllers an 18-minute warning of any potential collision, rather than the present two to three minutes.
At present, one in 10m flights ends with an accident caused by air traffic control. But in the constant congestion at 30,000ft predicted by 2020, that rate could mean two disasters in Europe's skies a year.
www.guardian.co.uk...
That is the norm but under the right rare conditions they might last five or even more minutes.
Which is one again not unexpected but should be far rarer than we observe it to be.
Why would so many thousands of people send emails or letters to their representatives about this phenomenon?
Who said that the equipment have to be installed
or that it is large?
Who suggested this operation uses commercial planes at all?
I know you want to debunk the whole thing as fast as possible but try stick to theories at least proposed?
As i understand it these materials would just be mixed with the fuel itself if the operation were to be carried out by commercial planes
Which would be a silly way to go about installing equipment you do not want people to know about?
Do 'debunkers' like yourself choose the most illogical way to keep a secret operation mostly secret by chance or do you do it out of shear spite? If you do not understand the notion of conspiracy do some research and discover what types of massive conspiracies are possible and have been perpetrated in relative broad daylight.
If there were holes to see and if these people would know about them why assume they would tell us?
"Federal" sums up everything you should know so don't lecture me on what they might know and what they are allowed to disclose to you and me.
but they most certainly do not and that has nothing to do with what they are allowed to disclose publicly.
Once again you focus entirely on the civilian aspect as if that is the main thrust of my argument; why?
I find that people working in fields they love are actually more easily bound by secrecy as they are even more unlikely to risk their jobs.
The assumption that my interest and belief in strange long lasting contrails stems from looking at a few pictures leads me to believe that you consider my absolutely foolish and probably stupid.
All i have seen so far is you appealing to convention and generally suggesting that since you can not imagine a conspiracy there can't be one while going about attacking claims i never made or even supported.
Do you think someone needs to be a aviation expert to realise that contrails that rarely lasted more than a few dozen seconds should not suddenly a few years later last many hours or even days?
At least i have been rather specific in calling only one person deluded and disrespectful while you have used a far broader brush for hundreds of thousands of Americans.
Well you should have said you 'will attempt' but this that statement was as revealing as anything more specfic.
Those would not be very smart pilots as they would have to assume that their flight plans are wrong. What about their cockpit would they be monitoring that would not have a sound or light cue to indicate noticeable deviation from the set norm? I am no expert but what i have described above seems to be norm in the books and material i have read....
And you will do this by staring out the cockpit window in your opinion? This is most certainly not the impression i got from what i have read...
And light aircraft are also very unlikely to fly at the altitudes normally associated with contrail formation....
How do you think staring out the cockpit window during night time would have prevented this accident? Why this sudden spate of 'accidents' anyways and why are they all being attributed to air traffic control and not to pilots failing to spot trouble by desperately peering out of little windows?
Stellar
Originally posted by selfless
magnito i think that some of the things you are saying is not healthy.
If you take time to think about not touching your face in public then that will be what causes you a disease.
Don't be paranoid about anything and simply don't think about it or else you will develope a disease called paranoya.
Are you suggesting that people should be more paranoid? wow that would be much worst then it already is...
Paranoya is not a healthy thing...
Im not trying to argue with you, i just don't agree with you on paranoya.
if you worry too much about something then it will happen in your mind.