posted 10-09-2002 03:29 PM
Well, today's comments by local meteorologists have been particularly annoying. Their forecasts for the Boston area repeatedly refer to "limited sunshine" for the next few days, and this morning we heard that "today is the last time we're going to see the sun for the next 3-4 days." Given the rather rapid build-up of "pretty clouds" over the last two days - the OBVIOUS result of the trailing that's been going on here - I don't doubt for a second that the now-completely obliterated sky is probably going to stay that way until at least this Saturday. It's HARDLY the first time we have directly witnessed this very graphic progression.
The junked-up sky over south-central Maine, in the photo submitted by "eyesopen" this morning under "Trails Reports", was commented on by "Canex", who said, "Nice looking cirrus clouds."
I found this rather annoying, too. It's one of those days if you know what I mean.
I hereby submit that what the __sleazebag debunkers__ are REALLY about is an agenda to deliberately create as much confusion as possible where the issue of CONTRAILS and their effects is concerned.
I'm going to leave it at that for the time being and let people come to their own conclusions after taking a few minutes to read through the material below. I would be interested in hearing what people think.
And, by the way, I HIGHLY DOUBT that "Canex" is Dr. Patrick Minnis, as the debunker crowd would have the rest of us believe.
Thank you.
-------------------------=>
National Aeronautics and Space Administration
Langley Research Center
Hampton, Virginia 23681-2199
For Release May 13, 2002
RELEASE NO. 02-035
NASA Scientists Use Empty Skies to Study Climate Change
http://www.larc.nasa.gov/news_and_events/inside_pages/2002/02-035.html
When the tragic events of September 2001 temporarily halted U.S. commercial air traffic, it created an opportunity to study the relationship between aviation and clouds.
From satellite observations taken during the air traffic shutdown, NASA scientists gained insight into the atmospheric conditions that govern the formation of contrails -- clouds caused by aircraft emissions.
"Because air traffic is expected to grow over the next 50 years, contrail coverage will also increase and may significantly impact the Earth's radiation budget by 2050," said Patrick Minnis, a senior research scientist at NASA's Langley Research Center in Hampton, Va.
The Earth's radiation budget -- the balance between the planet's incoming sunlight and outgoing heat energy -- drives climate change. Contrails can spread into extensive high, thin cirrus clouds that tend to warm the Earth because they reflect less sunlight back to space than the amount of heat they trap.
Tracking the formation of contrails is key to determining their contribution to cirrus clouds and their effect on the energy balance. But contrails typically form in large numbers from overlapping commercial flights, making it difficult for scientists to follow their development.
The air traffic shutdown gave Minnis and his team the chance to track individual, persistent contrails from military aircraft on September 12..... [more]
News In Science
9 August 2002
http://www.abc.net.au/science/news/enviro/EnviroRepublish_643595.htm
The Contrail Effect
US researchers have calculated that the water vapour exhaust trails, or contrails, left by cruising jet planes have a small effect on daily temperatures.
Dr Andrew Carleton at Pennsylvania State University and colleagues measured the effect of contrails during the three-day grounding of commercial aircraft after September 11 last year, when the terrorist attacks on the World Trade Centre and the Pentagon occurred.
Though the circumstances were tragic, the clear skies granted a unique opportunity to tease out the impact of contrails. Previously it was virtually impossible to measure their effect on climate because air traffic, especially over regions like Europe and North America, never stopped.
The researchers compared the average daily highest and lowest temperatures over North America for this period with records for the same interval between 1971 and 2000. Their results appear in this week's Nature..... [more]
Nature
8 August 2002
http://www.nature.com/nsu/020805/020805-7.html
Vapour trails' effects confirmed
Clouds formed by the water vapour in the exhaust from jet planes have a small but significant effect on daily temperatures, a new study confirms.
The grounding of commercial flights for three days after last September's terrorist attacks in the United States gave David Travis at the University of Wisconsin-Whitewater and colleagues a chance they never thought they'd have: to study the true impact that contrails from jet engines have on our climate1.
"It was a tarnished golden opportunity," recalls Patrick Minnis, an atmospheric scientist at NASA'a Langley Research Center in Hampton, Virginia. Despite a wealth of experiments, it had been virtually impossible to gauge the effect of contrails because air traffic, particularly over regions such as Europe and North America, never stopped. Until 11 September 2001, that is.
Contrails left high in the atmosphere spread out into cirrus-like clouds under the right atmospheric conditions. Natural cirrus clouds - thin layers of wispy water vapour that often resemble fish scales - trap heat being reflected from the ground and, to a lesser extent, reflect some of the Sun's rays..... [more]
Bradenton.com
11 August 2002
http://www.bradenton.com/mld/bradenton/news/nation/3842899.htm
Trails above fueling weather changes below, researchers say
(KRT) - Fluffy rows of cirrus clouds created by the increasing number of jet contrails can sometimes fill half the sky and may significantly affect ground temperatures, according to a report in Thursday's issue of the British science journal Nature.
Using a unique opportunity to study the effect of contrails on temperature after all commercial planes were grounded for three days after the Sept. 11 terrorist attacks, a team of researchers found that clouds spawned by jets lower peak daytime temperatures and raise the lowest nighttime readings.
Such temperature changes could have a profound impact, affecting growing patterns of some major crops and increasing the likelihood of larger insect populations, according to the researchers.
It may also be the clearest indication that human activity can alter the climate.
"We know for a fact that because of the contrails there are less clear days in the U.S. than there have ever been," said David Travis, a University of Wisconsin climatologist who headed the study. "We believe that human activity has much greater potential to change regional climate than it does to change global climate."..... [more]
Excerpted researchers' commentary:
*** From "NASA Scientists Use Empty Skies to Study Climate Change":
DR. PATRICK MINNIS: "Because air traffic is expected to grow over the next 50 years, contrail coverage will also increase and may significantly impact the Earth's radiation budget by 2050,".....
DR. PATRICK MINNIS: "Six aircraft were responsible for the formation of cirrus clouds that covered more than 20,000 square kilometers within an area between Virginia and central Pennsylvania,".....
Very revealing comment by DR. PATRICK MINNIS: "If scientists determine that contrails are negatively impacting climate change, we could minimize their formation by predicting where they will occur and then suggesting alternate flight altitudes accordingly, when feasible,".....
*** From "The Contrail Effect":
DR. ANDREW CARLETON: "Most researchers, however, believe that contrails will make global warming worse because they tend to spread out and become thin over time. It is these persisting contrails that have a climatic impact; not the transient ones that form and disappear within a few minutes.".....
*** From "Vapour trails' effects confirmed":
DR. ANDREW CARLETON: "It's obviously a significant effect,".....
DR. ANDREW CARLETON: "But locally, contrails are equally as significant as greenhouse gases,".....
DR. PATRICK MINNIS: "The discovery is important, especially when you consider that air traffic is expected to increase at about five per cent a year".....
*** From "Trails above fueling weather changes below, researchers say":
DR. DAVID TRAVIS: "We know for a fact that because of the contrails there are less clear days in the U.S. than there ever have been. We believe that human activity has much greater potential to change regional climate than it does to change global climate.".....
DR. DAVID TRAVIS: "During the three-day period when there were no commercial flights and only a few contrails from military planes, we got this sudden increase in the [diurnal] temperature range due to the fact that we suddenly had clearer skies across the country,".....
DR. PATRICK MINNIS: "This result, if it is corroborated by additional studies, represents the first large-scale evidence of the effect of contrails on climate,".....
DR. PATRICK MINNIS: "Six to eight contrails can grow to form a cloud cover the size of Massachusetts. These clouds now make up 4 to 6 percent of the cloud cover on any given day, a huge increase from the 1 to 2 percent previously estimated.".....
DR. DAVID TRAVIS: "Our winters have not been as dramatically cold in recent years as they have been historically. Some of what has been attributed to global warming may be due to contrails that throw down a blanket of clouds to warm the nights."
DR. DAVID TRAVIS: "Reducing the extremes of day and night temperatures could have a subtle impact on ecosystems. It may, for instance, increase insect populations that thrive better in moderate temperatures."
Final commentary by Dr. Travis:
Travis said he has mixed feelings about contrails. On the one hand they have been a prime focus of his research interest for the last 10 years. On the other hand they almost spoiled a recent vacation in the Pacific Northwest.
"There were so many contrails in the sky we weren't having any nice days," he said. "The contrails were making the days kind of gloomy and overcast. There aren't as many sunny days as we had when we were kids.