socrates wrote, "How come debunkers can't provide proof that chemtrails are contrails. They keep going around in circles. The two links above have nothing to do with chemtrails."
Scientists have proven that contrails can and do persist and morph into cirrus clouds...they even induce cirrus clouds where none were there before...did you actually read any of the papers??
"This guy is piling on the spam. Why couldn't he snip the parts where they say which aircraft emissions turned into what sized cloud cover and for how long. "
Scientific research, peer reviewed and tested is not spam. Because it does not fit your pre-conceived notion of what should be...you deride it and dismiss it...a closed minded debunker if there ever was one.
You want "snips" fine:
"About one half of the study contrails were generated by the sampling aircraft, a Cessna Citation, primarily at times of 3-15 min after generation"
from here: http://cat.inist.fr/?aModele=afficheN&cpsidt=1834780
"The impact of sulfur oxides on particle formation and contrails is investigated in the exhaust plumes of a twin-engine jet aircraft. Different fuels were used with sulfur mass fractions of 170 and 5500 ppm in the fuel, one lower than average, the other above the specification limit of standard Jet-A1 fuel. During various phases of the same flight, the two engines burnt either high- or low-sulfur fuel or different fuels in the two engines. Besides visual, photographic, and video observations from close distance, in situ measurements were made within the plumes at plume ages of 20 to 30 s, at altitudes between 9 and 9.5 km, and temperatures between -49 and -55°C, when the visible contrail was about 2 km long. The data include particle number densities for particles larger than 7 nm, 18 nm, 120 nm, and 1 μm in diameter, together with wind, temperature and humidity measurements. The observations show visible and measurable differences between contrails caused by the different sulfur levels. At ambient temperatures 5 K below the threshold temperature for contrail onset, the plume became visible about 10 m after the engine exit for high sulfur content, but 15 m after the engine exit for low sulfur content. The higher sulfur emission caused a larger optical thickness of the contrail shortly after onset, with slightly brown-colored contrail when the Sun was behind the observer, and more contrast when viewed against the Sun. The high-sulfur contrail grew more quickly but also evaporated earlier than the low-sulfur contrail. At plume ages of about 20 s, each engine plume was diluted to an effective diameter of 20 m. The plumes contained many subvisible particles. Peak number densities were 30,000 cm-3 for particles of diameter above 7 nm and 15,000 cm-3 above 18 nm. The latter is a little larger than the estimated number of soot particles emitted. The high-sulfur plume shows more particles than the low-sulfur plume. The differences are about 25% for particles above 7 nm and about 50% above 18 nm. The results indicate that part of the fuel sulfur is converted to sulfuric acid which nucleates with water vapor heterogeneously on soot or nucleates acid droplets homogeneously which then coagulate partly with soot. During descent through the level of contrail onset, the high-sulfur contrail remained visible at slightly lower altitude (25 to 50 m) or higher temperature (0.2 to 0.4 K). At least for average to high sulfur contents, aircraft generate an invisible aerosol trail which enhances the background level of condensation nuclei, in particular in regions with dense air traffic at northern latitudes and near the tropopause."
from here: http://cat.inist.fr/?aModele=afficheN&cpsidt=3039674
or this one which specifically links particular persistent contrails to commercial air traffic: http://cat.inist.fr/?aModele=afficheN&cpsidt=15775262
"Widespread persistent contrails over the western Great Lakes during 9 October 2000 were examined using commercial flight data, coincident meteorological data, and satellite remote sensing data from several platforms. The data were analyzed to determine the atmospheric conditions under which the contrails formed and to measure several physical properties of the contrails, including areal coverage, spreading rates, fall speeds, and optical properties. Most of the contrails were located between 10.6 and 11.8 km in atmospheric conditions consistent with a modified form of the Appleman contrail formation theory. However, the Rapid Update Cycle-2 analyses have a dry bias in the upper-tropospheric relative humidity with respect to ice (RHI), as indicated by persistent contrail generation during the outbreak where RHI ≥ 85%. The model analyses show that synoptic-scale vertical velocities affect the formation of persistent contrails. Areal coverage by linear contrails peaked at 30 000 km2, but the maximum contrail-generated cirrus coverage was over twice as large. Contrail spreading rates averaged around 2.7 km h-1, and the contrails were visible in the 4-km Geostationary Operational Environmental Satellite (GOES) imagery approximately 1 h after formation. Contrail fall speed estimates were between 0.00 and 0.045 m s-1 based on observed contrail advection rates. Optical depth measurements ranged from 0.1 to 0.6, with consistent differences between remote sensing methods. Contrail formation density was roughly correlated with air traffic density after the effects of competing cloud coverage, humidity, and vertical velocity were considered. Improved tropospheric humidity measurements are needed for realistic simulations of contrail and cirrus development."http://cat.inist.fr/?aModele=afficheN&cpsidt=15775262
"We have reanalyzed some of the best in-situ contrail data collected to date to explore how well
Eq. (3) predicts observations of the IWC within contrails. Some of the most reliable observations
come from the 12 May 1996 SUCCESS case study when the DC-8 generated a contrail while flying
in a racetrack pattern in highly ice supersaturated, cloud-free air (Heymsfield et al., 1998). Some 20
and 40 minutes after the initial contrail pass the DC-8 returned through the contrail, sampling it in a
racetrack pattern. These penetrations occurred long after the times required for the wake vortices to
develop oscillations that mixed the contrail plume with the environmental air, i.e. these samples can
be considered as taken from the later stage of contrail evolution. The DC-8 then sampled the
contrail particles as they grew in the ice supersaturated air (as ascertained from a TDL hygrometer)
for almost two hours following contrail formation. The accuracy of the TDL hygrometer was
established to be +/-5% based on contrail crossings and wave cloud penetrations at temperatures
between -40 and -65C."
from this paper: http://tinyurl.com/42wjzu
"Persistent contrails are a common feature of the upper troposphere. We describe two methods for intercomparing and evaluating RHi measurements in a persistent contrail with calculated or expected values. The methods were applied to measurements made in the upper troposphere on board an NASA WB-57F aircraft while sampling its own contrail. Included in the analysis are measurements of water vapor pressure, temperature, ice particle number and size, and nitric oxide (NO). The systematic use of these contrail-sampling methods in future studies will improve our understanding of contrail microphysics and the performance of fast-response water and temperature measurements."
take from here: http://tinyurl.com/3u92fe
What do you make of this quote: "Bryson and Wendland (1975) estimated that contrails may have increased the cirrus cloud cover over North America by 5%–10% since the early 1960s; their calculations assumed that 50% of all flights produce contrails that persist for at least 2 hours"
from here: http://tinyurl.com/66qouz
Or this one which follows specific contrails for over 2 hours:http://tinyurl.com/3fx7sk
This one isn't sampling contrails but it is measuring aerosols in aircraft exhaust:http://tinyurl.com/4kapyd
Socrates...Please clarify your belief of contrails....is any trail that persists a "chemtrail" ...or is it that some contrails persist but "chemtrails" only come from military airplanes...
Surely, the overwhelming body of research regarding contrails persisting should give you and understanding that even "normal" contrails can and do persist.
"Of course chemtrails are going to take advantage of higher humidity/temperature situations. But the fact that they have chemtrailed into pure blue sky and very warm conditions is proof that chemtrails are not contrails. All these debunker points have been defeated all over the top two sections. These are time wasters and evokers of authority. I really believe it's time for them to go, at least foolsbreath. "
First off, conditions on the ground have NO bearing on conditions aloft...if its 100 degrees on the ground it can still -40 at 35K feet. Moreover, ice supersaturation often occurs in CLEAR AIR...That is why persistent contrail are causing such a concern because they create their own...and additional- cirrus clouds where there were none before.
"As I told may41970, you are not wanted here. Those who spread willing disinfo get permanently banned."
If you think the large body of scientific evidence regarding persistent contrail and contrail cirrus is disinfo...well, I can't help you with that...That is not the talk of an open-mind.
Good luck with that.