Featured Research

from universities, journals, and other organizations

Excess Water Vapor Near Cirrus Clouds Puzzles Scientists

Date:
December 1, 2006
Source:
University of Washington
Summary:
Researchers in recent years have found water vapor at concentrations as much as twice what they should be in and around cirrus clouds high in the atmosphere, a finding that could alter some conclusions about climate change. A group of European and US scientists is advocating a broad research effort to solve the puzzle.

Cirrus clouds with fog beginning to roll in over the Coast Range. Purisima Creek Redwoods, Bay Area, California, October 2003.
Credit: Photo Captain Albert E. Theberge Jr., NOAA Corps (ret.)

A number of researchers in recent years have reported perplexing findings of water vapor at concentrations as much as twice what they should be in and around cirrus clouds high in the atmosphere, a finding that could alter some conclusions about climate change.

Related Articles


Now a group of European and U.S. scientists is advocating a broad research effort to solve the puzzle and understand just what is occurring in cirrus clouds, wispy sheets of ice crystals 6 to 10 miles above the Earth's surface.

"Based on our current knowledge, it shouldn't exist," said Marcia Baker, a University of Washington professor of Earth and space sciences. She is one of six climate researchers who authored a Perspectives article in the Nov. 30 edition of the journal Science promoting an extensive effort to investigate the dilemma.

Part of the problem is that many atmospheric scientists have dismissed the findings as erroneous because the current understanding of atmospheric conditions and cirrus clouds would make the water vapor anomaly impossible, Baker said. Yet a number of pieces of evidence published in peer-reviewed journals and presented at scientific meetings during the last six years have supported the finding.

Clouds and particles in the atmosphere play a significant role in regulating the Earth's temperature because they help determine how much of the sun's heat and energy is reflected back into space and they trap outgoing radiation from the Earth's surface. Cirrus clouds also are important in regulating the distribution of water vapor, the most important greenhouse gas, in the upper troposphere.

"We have thought our models of the formation and evolution of cirrus clouds are generally adequate in how they portray the role of cirrus clouds in regulating water vapor, but if the recent findings are accurate and high humidities are widespread, our assumptions could need significant adjustment," Baker said.

"The point is to bring this to the more general science audience as a broad puzzle, but also to lay the groundwork for research to solve the puzzle," she said.

Cirrus clouds form in the upper troposphere and modulate the exchange of water between the troposphere and the stratosphere. Vapor in the upper troposphere can rise into the stratosphere but tiny ice crystals can fall back toward the surface.

Outside the clouds, there are water vapor and minute atmospheric particles called aerosols, but no ice crystals. Scientists have come to expect that new ice crystals will begin to form in aerosols when vapor levels rise to the point at which they are 60 percent above equilibrium with the surrounding air. Yet measurements have shown that vapor levels can reach 90 percent to 100 percent above equilibrium without forming new ice particles.

Inside the clouds, it is expected that vapor levels above equilibrium cannot be maintained, yet evidence shows that often vapor levels are as much as 30 percent above equilibrium in large areas of clouds.

Scientists have speculated about what causes these anomalies. It is possible the aerosols might have as-yet undiscovered properties that prevent crystals from forming in some conditions, or there could be some kind of coating on the aerosols that prevents ice from forming, Baker said. There also could be some undiscovered property of ice crystals that prevents them from growing in certain conditions.

"There could be a different phase of ice at the temperatures and pressures in cirrus clouds that has a higher equilibrium for vapor," Baker said. "These are the kinds of questions for which we are trying to find answers."

The lead author of the Science article is Thomas Peter of the Institute for Atmospheric and Climate Science at Eidgenφssische Technische Hochschule of Switzerland. Other co-authors are Claudia Marcolli, Peter Spichtinger and Thierry Corti, also of the climate institute, and Thomas Koop of Bielefeld University in Germany.


Story Source:

The above story is based on materials provided by University of Washington. Note: Materials may be edited for content and length.


Cite This Page:

University of Washington. "Excess Water Vapor Near Cirrus Clouds Puzzles Scientists." ScienceDaily. ScienceDaily, 1 December 2006. <www.sciencedaily.com/releases/2006/11/061130191409.htm>.
University of Washington. (2006, December 1). Excess Water Vapor Near Cirrus Clouds Puzzles Scientists. ScienceDaily. Retrieved April 21, 2015 from www.sciencedaily.com/releases/2006/11/061130191409.htm
University of Washington. "Excess Water Vapor Near Cirrus Clouds Puzzles Scientists." ScienceDaily. www.sciencedaily.com/releases/2006/11/061130191409.htm (accessed April 21, 2015).

Share This


More From ScienceDaily



More Earth & Climate News

Tuesday, April 21, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Going Ape: Sierra Leone Chimpanzees Hail Ebola Retreat

Going Ape: Sierra Leone Chimpanzees Hail Ebola Retreat

AFP (Apr. 21, 2015) — As money runs out at Tacugama Chimpanzee Sanctuary in Sierra Leone, around 85 chimps are facing homelessness. The centre closed when the Ebola epidemic was ravaging the country but now that closure is beginning to look permanent. Video provided by AFP
Powered by NewsLook.com
Wild Weather Lashes Sydney Region

Wild Weather Lashes Sydney Region

AFP (Apr. 21, 2015) — Sydney and surrounding areas are lashed by wild weather with trees felled, power cuts hitting thousands of homes and sand drifts sweeping inland off the iconic Bondi beach. Duration: 00:50 Video provided by AFP
Powered by NewsLook.com
Deepwater And Dolphins: The Oil Spill's Impact 5 Years On

Deepwater And Dolphins: The Oil Spill's Impact 5 Years On

Newsy (Apr. 20, 2015) — Five years on, the possible environmental impact of the Deepwater Horizon spill includes a sustained die-off of bottlenose dolphins, among others. Video provided by Newsy
Powered by NewsLook.com
Pee-Power Toilet to Light Up Disaster Zones

Pee-Power Toilet to Light Up Disaster Zones

Reuters - Innovations Video Online (Apr. 20, 2015) — Students and staff are being asked to use a prototype urinal to &apos;donate&apos; urine to fuel microbial fuel cell (MFC) stacks that generate electricity to power lighting. The developers hope the pee-power technology will light toilet cubicles in refugee camps, where women are often at risk of assault in poorly lit sanitation areas. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins