World's biggest jet engine about to get bigger, quieter ..and make more contrails

a reply to: luxordelphi

Again, you have honest to God proof, right? Not just some website saying so, or a misunderstanding of a study, but honest to God real proof that thousands of atmospheric scientists around the world have no idea what they're taking about.

a reply to: Zaphod58

No,that would be impossible. But as with a court of law, even if your idea is immensely stupid, as long as you say it and the jury hears it, then the seed is planted. It's just a game the chemtrail folks play. She has neither proof or a clue.

a reply to: Zaphod58

Again, you have honest to God proof, right? Not just some website saying so, or a misunderstanding of a study, but honest to God real proof that thousands of atmospheric scientists around the world have no idea what they're taking about.

Of course there will be no honest to god proof, because just like usual chemtrail believers when they see something they don't understand they find it much easier to throw crap against the wall and then use whatever sticks as evidence.

a reply to: network dude

She has neither proof or a clue.

That was shown when the comment about atmospheric humidity was posted.

a reply to: Phage

Lack of humidity information actually begins with the OP study. (The 14 year old study that the OP and thread title are based on.)

Experimental Test of the Influence of Propulsion Efficiency on Contrail Formation

You, deftly, previously, took the focus off that line of discussion (which was headed down a slippery slope) by waving the humidity flag.

However, throwing out 3 and 4 letter abbreviations (RUC = Rapid Update Cycle) (ARPS = Advanced Regional Prediction System) to prove humidity data is dotty. (NWA - numerical weather analyses.)

Relating observations of contrail persistence to numerical weather analysis output

NWAs, however, often underestimate upper tropospheric relative humidity (UTH) due to large dry biases in the balloon soundings used to construct the analyses and to internal adjustments made to meet the model's physical constraints (Minnis et al., 2005b).

To repeat: humidity, in this pseudo science of persistence, is determined by occurrence. There is no humidity data except for isolated cylinders of air measured by rising radiosondes spaced very far apart and large averages from satellites. Read:

Measurement...Determination of humidity

a reply to: luxordelphi

You, deftly, previously, took the focus off that line of discussion (which was headed down a slippery slope) by waving the humidity flag.

I said more efficient engines can produce contrails more often than older engines. I also said persistence is determined by humidity. For some reason you then started claiming that upper air humidity data was being provided by school children.

Relating observations of contrail persistence to numerical weather analysis output

Yes, the known dry biases in radiosonde data are known. It is known that humidity levels tend to show on the low side.

There is no humidity data except for isolated cylinders of air measured by rising radiosondes spaced very far apart and large averages from satellite

True. But models are accurate enough to correlate with corrected radiosonde data and the observation of persistent contrails, which is what the paper you posted is about.

This paper evaluates the potential for using the RUC and ARPS models to diagnose and predict persistent contrail formation conditions using a variety of datasets.

www.atmos-chem-phys.net...

a reply to: luxordelphi

Really. You need to start telling the atmospheric scientists then.

They clearly state here that atmospheric samples were taken on aircraft, as well as with other sampling methods, and all clearly showed high humidity levels in contrail areas.

Visible contrails observed during SUCCESS persisted longer than a few minutes only when substantial ambient supersaturations with respect to ice existed over large regions. On some occasions, contrails formed at relatively high temperatures (≥−50°C) due to very high ambient supersaturations with respect to ice (of the order of 150%). These warm contrails usually formed in the presence of diffuse cirrus. Water vapor from sublimated ice crystals that entered the engine was probably necessary for contrail formation in some of these cases. At temperatures above about −50°C, contrails can only form if the ambient air is supersaturated with respect to ice, so these contrails should persist and grow.

onlinelibrary.wiley.com...

Again, expected conditions.

I could go on. There are literally dozens of studies that all show high humidity levels when contrails persist, with levels sampled from aircraft and other methods in the area of the contrails.

originally posted by: Phage
I said more efficient engines can produce contrails more often than older engines.

And as proof......

A340 and 707 side by side

On the left is an Airbus A340, with newer high bypass turbofans, which are much more efficient than older engines. On the right, a Boeing 707, using much older turbofans (military designation is TF33).

a reply to: network dude

But as with a court of law, even if your idea is immensely stupid, as long as you say it and the jury hears it, then the seed is planted.

It wasn't my idea to have elementary school children determine persistence parameters. It was the idea of the researchers listed as authors on this paper:

Relating observations of contrail persistence to numerical weather analysis output

However 'immensely stupid' it was/is or wasn't/isn't is irrelevant. What does matter is that no humidity data other than the same hit and mostly miss stuff was gathered. And that in order to gather no data on persistence parameters, school children and satellites were called in.

(The school children take up 1.5 pages of this 8 page document. Another page is mostly credits while the first page is mostly preamble and build-up.)

a reply to: Zaphod58

Your proof:

Experimental Test of the Influence of Propulsion Efficiency on Contrail Formation

consists of 2 (two) jets; one old and one new. They flew up and then they flew down. They produced contrails within 50 seconds of each other. They never achieved cruise because the research craft (Falcon) wasn't able to follow. One of the jets produced a contrail out of the engines on one wing but not the other - they think the pilot was fiddling with it but they're not sure. Oh and, of course, the newer jet was on autopilot while the older one was not and this caused inefficiencies in the newer jet they think.

Almost forgot...what do they have to say about humidity?

The accuracy of the humidity is less than usual (4%) in this case, because of some uncertainty in the calibration factors.

originally posted by: luxordelphi
Atmospheric humidity, at large, is determined by elementary school children and then backed into models so that if a contrail persists, it is assumed that the humidity is conducive.

Can you propose another reason for contrail persistence?

originally posted by: luxordelphi
a reply to: network dude

But as with a court of law, even if your idea is immensely stupid, as long as you say it and the jury hears it, then the seed is planted.

It wasn't my idea to have elementary school children determine persistence parameters. It was the idea of the researchers listed as authors on this paper:

Relating observations of contrail persistence to numerical weather analysis output

You could try to expand your knowledge past that one paper and find some others.

By clicking on this link.

The ambient temperatures and humidities required for contrail formation and persistence are determined from in situ measurements during the Subsonic Aircraft: Contrail and Cloud Effects Special Study (SUCCESS) experiment.

And these studies used scientific instruments instead of kids. Imagine that.

a reply to: luxordelphi

They never achieved cruise because the research craft (Falcon) wasn't able to follow.

Did you even pay attention to what was written under the picture?

Fig. 3 Airbus A340 with contrails (left) and the Boeing B707 without contrails (right) taken from the Falcon research aircraft at about  flight level
344 hft at 7:40 UTC, 15 Sept. 1999.

So then how do you get a flight level test done if the Falcon isn't able to follow.

Also please let me show you something about the Falcon...

Performance

Altitude [ft]
10 000

20 000

31 000

41 000

max. Range [NM]
1150

1500

1700

2000

max. Endurance [h:min] 04:10
04:15

04:45

05:00


max. Altitude
42 000 ft

12 800 m

max. Speed (VMO / MMO)
380 KCAS

0,865 Mach
Long Range Speed
410 KTAS

0,720 Mach
Takeoff Distance (MTOM, ISA, MSL)
2000 m

6562 ft

www.dlr.de...

So please show me where this jet that is specifically set up to test plane contrails at flight altitude couldn't get up there to test these contrails?

I must ask do you understand what you read or do you just decide to not understand on purpose?

a reply to: luxordelphi

They flew up and then they flew down. They produced contrails within 50 seconds of each other.

Both of them? An A340 has high bypass turbofans. How can that be when no less an authority than Wiggington claims the high bypass turbofan engines are nearly incapable of producing condensation trails? Wiggington said "Only under the most extreme conditions can they create the smallest, most short-lived almost transparent trail".
That is from the interview available here- itsrainmakingtime.com...

You argued in support of Wiggington's claims. An explanation would be welcomed.

a reply to: DenyObfuscation

I am not sure they still stand by all that, as the claim kind of backs them into a corner. If they stick to that, and we find just one plane flying and leaving an "outrageously persistent contrail" and the plane can be identified as a commercial flight with passengers, the whole chemtrail theory (as I understand it) will be smashed to tiny little bits.

a reply to: network dude
If only it were that easy. The "chemtrail" theory is like the Hydra.

Hercules attacked the many heads of the hydra, but as soon as he smashed one head, two more would burst forth in its place!

www.perseus.tufts.edu...

Myths aren't hampered by 'silly' notions of truth and such.

a reply to: mrthumpy

Can you propose another reason for contrail persistence?

Yes I can: "...a tragically altered atmosphere." That's a quote from Carnicom.

The RH Deception

a reply to: network dude

The bulk of your search returns and the document you quoted are all from the late 1990's. In 2009, we all were still on the hunt for humidity values, with kids in tow. Imagine that.

a reply to: tsurfer2000h

Oh for heaven's sake! Read the article before you start typing.

Experimental Test of the Influence of Propulsion Efficiency on Contrail Formation

The maximum cruise speed of the Falcon (about 220 m s -1, Mach 0.74) is considerably smaller than those of the two other aircraft. Therefore, the B707 and A340 flew at reduced power to let the Falcon follow at constant distance. At lower power, the engine efficiencies are smaller than at nominal cruise conditions.

The observations took place over southern Germany at 48.27N (ascent) and 48.56N (descent), between 10.5E and 12E, from 7:20 to 7:42, 15 September 1999 [all times are universal time, co-ordinated (UTC)]. The aircraft ascended from 310 to 350 hft while flying eastward, turned, and then descended westward. The aircraft ascended until 7:31 and descended after7:37 at a rate of 300 ft min -1 (100 m min -1).