NASA: All of 1975-1994 warming could be contrails!

NASA scientists have found that cirrus clouds, formed by contrails from aircraft engine exhaust, are capable of increasing average surface temperatures enough to account for a warming trend in the United States that occurred between 1975 and 1994.

Patrick Minnis, Senior Research Scientist at NASA's Langley Research Center in Hampton, VA,
determined the observed one percent per decade increase in cirrus cloud cover over the United States is likely due to air-traffic-induced contrails.

Using published results from NASA's Goddard Institute for Space Studies (New York) general circulation model, Minnis and his colleagues estimated contrails and their resulting cirrus clouds would increase surface and lower atmospheric temperatures by 0.36 to 0.54 degrees Fahrenheit per decade. Weather service data reveal surface and lower atmospheric temperatures across North America rose by almost 0.5 degree Fahrenheit per decade between 1975 and 1994.

Minnis worked with colleagues Kirk Ayers, Rabi Palinkonda, and Dung Phan from Analytical Services and Materials, Inc., of Hampton, VA. They used 25 years of global surface observations of cirrus clouds, temperature and humidity records from the National Centers for Environmental Prediction (NCEP) reanalysis dataset. They confirmed the cirrus trends with 13 years of satellite data from NASA's International Satellite Cloud Climatology Project.

The study was published in the Journal of Climate.

Here is a link to the article I have quoted announcing the study:

http://www.sciencedaily.com/releases/2004/04/040428061056.htm

I'm not sure this helps the AGW skeptics argument. If I'm reading this correctly, contrail induced warming is a regional effect. In that same article you reference it says:

"This result shows the increased cirrus coverage, attributable to air traffic, could account for nearly all of the warming observed over the United States for nearly 20 years starting in 1975, but it is important to acknowledge contrails would add to and not replace any greenhouse gas effect," said Patrick Minnis, senior research scientist at NASA's Langley Research Center in Hampton, Va. The study was published April 15 in the Journal of Climate. [COLOR="Blue"]"During the same period, warming occurred in many other areas where cirrus coverage decreased or remained steady,[/COLOR]" he added.

The NASA page on this is at

http://www.nasa.gov/centers/langley/news/releases/2004/04-140.html


KMM

Hugh Bartlett said:

NASA scientists have found that cirrus clouds, formed by contrails from aircraft engine exhaust, are capable of increasing average surface temperatures enough to account for a warming trend in the United States that occurred between 1975 and 1994.

Patrick Minnis, Senior Research Scientist at NASA's Langley Research Center in Hampton, VA,
determined the observed one percent per decade increase in cirrus cloud cover over the United States is likely due to air-traffic-induced contrails.

Using published results from NASA's Goddard Institute for Space Studies (New York) general circulation model, Minnis and his colleagues estimated contrails and their resulting cirrus clouds would increase surface and lower atmospheric temperatures by 0.36 to 0.54 degrees Fahrenheit per decade. Weather service data reveal surface and lower atmospheric temperatures across North America rose by almost 0.5 degree Fahrenheit per decade between 1975 and 1994.

Minnis worked with colleagues Kirk Ayers, Rabi Palinkonda, and Dung Phan from Analytical Services and Materials, Inc., of Hampton, VA. They used 25 years of global surface observations of cirrus clouds, temperature and humidity records from the National Centers for Environmental Prediction (NCEP) reanalysis dataset. They confirmed the cirrus trends with 13 years of satellite data from NASA's International Satellite Cloud Climatology Project.

The study was published in the Journal of Climate.

Here is a link to the article I have quoted announcing the study:

http://www.sciencedaily.com/releases/2004/04/040428061056.htm