posted 02-14-2003 10:47 PM            

One landmark publication by this publicly funded researcher was a year long survey of contrails across the continent, "Surface-Based Observations of Contrail Occurrence Frequency Over the U.S., April 1993--April 1994 ".

This busy government employee managed to actually publish these data three years later,
http://techreports.larc.nasa.gov/ltrs/refer/1997/NASA-97-rp1404.refer.html

What we learned from this seminal paper was that there was a much higher occurance of persistent contrails in the winter months than in the summer months.

This, of course, stands to reason...colder temperatures aloft coupled with high relative humidity. It is these conditions that promote contrail persistence.

The contradiction that I've observed is this... in the San Francisco Bay Area there has been a greatly reduced occurance of the dramatic horizon-to-horizon contrails compared to the warmer, drier months of last summer.

Now we've been lectured to, by those who claim to know, that it's ALWAYS very cold up there...and that conventional atmospheric soundings consistently UNDER ESTIMATE humidity at low temperatures...and they state that it is for this reason that such persistent trails are perfectly normal during the high pressure, dry summer months.

So OK, lets say that's true.

I'm waiting for these same pundits to provide such a scholarly rationale as to why such persistent trails have virtually disappeared from our skies recently.

It couldn't be that our military is preoccupied in other parts of the world.

Nevertheless, there must be an perfectly sound explanation, grounded in rational, scientific, irrefutable, fact.

posted 02-14-2003 11:33 PM            

Ummmm, they havent. Ive seen these persistant contrails frequently over the past few days.

posted 02-15-2003 12:28 AM            

let's play dramatic change in sea water temps shall we !

JUNE 27 2002

DECEMBER 02 2002

posted 02-21-2003 02:05 PM            

Unusually cold? Nope, actually unusually warm.

Unusually humid? Nope, we're experiencing high pressure right now.

Expanation from the debunkers?

Nope, they are all under their rocks.

posted 02-21-2003 03:46 PM            

Nope, they are all under their rocks.

Just as well.<<

According to the 12 Zulu upper air charts, there is considerable amount of cold air moving into the west coast. The dewpoint depressions have fallen to less than 8 deg C over your area. Hmmm, cooler and relatively more moist? Sounds like ingredients for persistent contrails to me.

posted 02-21-2003 09:46 PM            

What an interesting explanation.

I am so curious as to why we haven't experienced such weather conditions during the past month or more.

Please provide a link for your source of information.

Given that air traffic is relatively constant, it is reasonable to expect that under comparable conditions we should expect the same horizon-to-horizon displays.

So lets see. Atmospheric physics and chemistry should be a constant.

I'll be happy to report as to whether there is any consistency in such observations.

posted 02-21-2003 11:16 PM            

Here is the link. http://www.spc.noaa.gov/cgi-bin-spc/getuadata.spc?MyDate1=030220&Time1=12&MyDate2=&Time2=12&Align=V&Levels=All

Please pay particular attention to 500mb and above.

Just for fun, I went back 15 days to check the analysis:
http://www.spc.noaa.gov/cgi-bin-spc/getuadata.spc?MyDate1=030206&Time1=12&MyDate2=&Time2=12&Align=V&Levels=All

Notice the very wide dewpoint depressions. I only took a short perusal of the maps but I'd say probably no persistent trails over SF that day.

F.K.

posted 02-21-2003 11:57 PM            

s t r e t c h ... the facts to fit your story.

For the record, today's soundings from Oakland:

Pressure_Alt DD Dir Spd ---Temp--- DewPt
(ft) (mb) (kts) (F) (C) (C)

posted 02-22-2003 05:58 AM            

Thanks,

posted 02-22-2003 06:01 AM            

Thanks,

posted 02-22-2003 06:19 AM            

Thanks,

posted 02-22-2003 11:37 AM            

This is the link I use for Oakland, California soundings:
http://www-frd.fsl.noaa.gov/mab/soundings/reply-skewt.cgi?data_sou rce=MAPS&lon=-104.67&lat=39.87&airport=oak

The horizon-to-horizon trails were apparent on my way to work (around 8:00 AM) and continued throughout the day.

Clear blue sky so far today.

Maybe we've gone to Code Red and all flights have been cancelled.

By the way, it's become increasingly difficult to access or post on this site.

posted 02-22-2003 03:43 PM            

One quick observation about your sounding link. These sounding are not generated by actually oberserved conditions. Rather based on the RUC numerical model. The RUC, as I recall has a severe dry bias at upper levels. Now, I have not looked at a rawinsonde observation from the 21st yet so I haven't drawn a conclusion yet.

Try this link for a start: http://enso.larc.nasa.gov/sass/contrail_forecast/contrail_prediction.html#REALTIME

The only upper air data I would trust to give a reasonably good representation of the atmosphere is rawinsonde data (weather balloon). Oakland does have an upper air site.

Here is one link to see that latest Skew-T diagrams. I can explain how to read it if you need.
http://meteora.ucsd.edu/wx_pages/upper_air.html

posted 02-22-2003 06:44 PM            

Thank you for the links.

I assume that your offer to provide guidance and interpretation is sincere.

Using the archives at the link:
http://enso.larc.nasa.gov/sass/contrail_forecast/contrail_prediction.html#REALTIME

Please provide the parameters that would indicate the formation of persistent contrails in the San Francisco Bay Area on Friday, February 21, 2003.

and then, compare this to today, Saturday February 22nd, when there weren't horizon-to-horizon trails.

We're talking science here...reproducible data...and the laws of atmospheric chemistry and physics.

Either it makes sense or it doesn't.

If not, it's reasonable to ask why.

posted 02-23-2003 12:24 AM            

Here are some other links that may help you in the explanation as to why there were horizon-to-horizon persistent contrails in the San Francisco Bay Area on Friday, February 21 and none today, Saturday, February 22nd.

What objective, measureable data can account for the dramatic difference the the persistence of contrails in our sky between these two days?

Here is some vapor data, 9:00 AM each day:

Friday, February 21, 2003 http://www.atmos.washington.edu/images/wv_enhanced/2003022109.gif

posted 02-23-2003 01:12 PM            

Feeling Kocky's nap will be greatly extended.

No helpful debunker will respond specifically to the above questions.

Within a week or so the vapor satellite shots of the West Coast will beome stale and no longer available.

I guess it's difficult to get out from under those rocks.

Then again, given current atmospheric conditions, maybe that's the safest place to be these days.

Especially if it is one of those taxpayer funded, luxuriously equipped government burrows for members of the ruling regime.

Nevertheless, despite a professed offer to help interpret data, Feeling Kocky is AWOL...as are other prominent debunkers who frequent this board.

posted 02-23-2003 07:38 PM            

>>Please provide the parameters that would indicate the formation of persistent contrails in the San Francisco Bay Area on Friday, February 21, 2003.<<

If you read Dr. Minnis's papers you will see that development of persistent contrails is not always a yes/no question. Surely you don't want me to rehash all the stuff that was posted by him(See the thread "Contrail Factors/Canex which has excellent information on how to predict perstent contrails). Canex most definately has a clue about contrails. I would probably only quote his words since it is obvious that he knows what he is talking about. I am an operations meteorologist. I forecast the weather, so I can't call myself an official "expert" on persitent contrails becuase they generally don't have any affect on the forecast.

>>Nevertheless, despite professed offer to help interpret data, Feeling Kocky is AWOL...as are other prominent debunkers who frequent this board.<<

If you want me to give you my opinion on whether or not contrials are possible at a given time, I will give you my opion. AWOL? Whatever. Some of us lowly stupid "debunkers" actually have a life outside this message board.

posted 02-23-2003 08:33 PM            

ST must be AWOL.

Sorry, bud, I couldn't resist.