The relative humidity data from the RUC 40km model are suspect since 18 April, 2002. Forecasts since April 18, 2002 are suspect. To obtain a better estimate of potential contrail formation, examine the 'Individual level (mb)' results. Select a pressure value between 200 and 250 mb for the best estimate. Relative humidity values above 80% are good indicators of contrails in the new RUC data. You can use any pressure level , but the large values may be too warm for contrail formation.
Conditions were not right for contrail formation.
Originally posted by ProudBird
reply to post by pianopraze
Quite normal contrails.
And, I am puzzled because you added the screen shot from Flight Aware, but then said there were "more" airplanes than shown on Flight Aware?
I saw plenty in that screen grab. Since it was not interactive, I can not tell what each airplane's type and altitude was.
Also, keep in mind that Flight Aware, while "real time", does indeed have a slight time delay. I have researched it (by listening to ATC at airports, and then watching the flights that I hear on the radio compared to how they show up on Flight Aware) and found about an 8-minute delay in what's shown on Flight Aware, to actual "real time".
For a jet at cruise altitude, 8 minutes = anywhere from 50 to 60 miles distance.
Originally posted by Afterthought
reply to post by pianopraze
Great catch!
We see so many threads where they have daytime photos, so this is a real treat you've given us. Truly amazing the way the trails dissipate so quickly. I like the way you cross checked them with the radar imaging, too.
Maybe I missed it, but did you say what the wind was like that evening? Did it rain soon after?
Edit to Add: The moon was magnificent, wasn't it?
edit on 10-3-2012 by Afterthought because: (no reason given)
Originally posted by Afterthought
reply to post by pianopraze
Maybe this is a dumb question and I'm not reading your other data properly, but what is making that blue light in the sky in the 9:08 photo and thereafter?
It is possible that this was a military exercise and they did not show on flight aware.
Originally posted by ProudBird
reply to post by pianopraze
It is possible that this was a military exercise and they did not show on flight aware.
While the military flights might not show on Flight Aware, the term "military exercise" is a bit much. Could be as simple as transports en-route to somewhere, and/or tankers also en-route. Where they orbiting nearby? If so, then it would loosely qualify as an "exercise".
This reminds me of the "8 chemtrails" thread from a week or so back. In that case it was found to be the USAF Thunderbirds flying overhead, they had left one Air Show venue and were en-route to someplace else.
Yes, even an F-16 will make a contrail, when conditions are ripe.
All these planes were very high in the sky. They were not f-16, they were very large and very high.
Efficient formation of stratospheric aerosol for climate engineering by emission
of condensible vapor from aircraft
Jeffrey R. Pierce
Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada
effectiveness of stratospheric aerosol climate engineering through emission of non-condensable vapors such as SO2 is limited because the slow conversion to H2SO4 tends to produce aerosol particles that are too large; SO2 injection may be so inefficient that it is difficult to counteract the radiative forcing due to a CO2 doubling. Here we describe an alternate method in which aerosol is formed rapidly in the plume following injection of H2SO4, a condensable vapor, from an aircraft. This method gives better control of particle size and can produce larger radiative forcing with lower sulfur loadings than SO2 injection.
www.agu.org...
edit on 10-3-2012 by burntheships because: (no reason given)
I would wager a bet if those contrails could be tested, we would find some type of
particulate matter....
Originally posted by ProudBird
reply to post by pianopraze
Yes, I used that other thread (with an overly sensationalized title) as an example:
All these planes were very high in the sky. They were not f-16, they were very large and very high.
In that instance, all eight were on the same course, and they too were not orbiting.
Since you said the the flight you saw were not orbiting either, then they were simply large jets at high altitude en-route to somewhere, each on their own course to destination, and forming perfectly normal contrails.
Your link to the radiosonde was data from time 0000Z, 7 March 2012. Your photo session was at between 2030 and 2115 EST, correct? Same date, I presume?
Zulu time (GMT) is five hours later then EST. So, the radiosonde data report from 0000Z means it was 1900 EST.
The atmosphere can change a lot in only one or two hours. But, this isn't even necessary, since the Appleman Chart clearly shows that at the temperatures recorded, contrails were likely.
That applet, I've seen it before, and it seems to need some tweaking.
You cetainly caught quite a few planes off the radar, and they are the ones
that left trails, persistent contrails.
You are correct in your assumptions. March 7, times as noted on photos.
4.1. Airplanes
Existing small jet fighter planes, like the F-15C Eagle (Figure 2a), are capable of flying into the lower stratosphere in the tropics, while in the Arctic, larger planes, such as the KC-135 Stratotanker or KC-10 Extender (Figure 2b), are capable of reaching the required altitude. ......
The Northrop Grumman RQ-4 Global Hawk can reach 20 km without a pilot but costs twice as much as an F-15C. Current designs have a payload of 1-1.5 tons. Clearly it is possible to design an autonomous specialized aircraft to loft sulfuric acid precursors into the lower stratosphere, but the current analysis focuses on existing aircraft.
Options for dispersing gases from planes include the addition of sulfur to the fuel, which would release the aerosol through the exhaust system of the plane, or the attachment of a nozzle to release the sulfur from its own tank within the plane, .......
The military has already manufactured more planes than would be required for this geoengineering scenario, potentially reducing the costs of this method. Since climate change is an important national security issue [Schwartz and Randall, 2003], the military could be directed to carry out this mission with existing aircraft at minimal additional cost. ...
Unlike the small jet fighter planes, the KC-135 and KC-10 are used to refuel planes mid-flight and already have a nozzle installed. In the tropics, one option might be for the tanker to fly to the upper troposphere, and then fighter planes would ferry the sulfur gas up into the stratosphere (Figure 2b). It may also be possible to have a tanker tow a glider with a hose to loft the exit nozzle into the stratosphere.
Fortunately the coldest cirrus have the highest ice supersaturation due to the dominance of homogeneous freezing nucleation. Seeding such cirrus with very efficient heterogeneous ice nuclei should produce larger ice crystals due to vapor competition effects, thus increasing OLR and surface cooling. Preliminary estimates of this global net cloud forcing are more negative than −2.8 W m−2 and could neutralize the radiative forcing due to a CO2 doubling (3.7 W m−2). A potential delivery mechanism for the seeding material is already in place: the airline industry. iopscience.iop.org...
