Featured Research

from universities, journals, and other organizations

Laser-brightened cirrus clouds

Date:
June 5, 2013
Source:
Karlsruhe Institute of Technology
Summary:
Intense laser light pulses increase the brightness of high cirrus clouds. Scientists have been investigating the interactions of laser light and ice clouds using a unique AIDA aerosol and cloud chamber.

At the AIDA facility on KIT’s Campus North, researchers investigate aerosol and cloud processes under atmospheric conditions.
Credit: Markus Breig, KIT

Intense laser light pulses increase the brightness of high cirrus clouds. Together with colleagues from Berlin and Geneva, climate researchers from Karlsruhe Institute of Technology (KIT) have been investigating the interactions of laser light and ice clouds using the unique AIDA aerosol and cloud chamber on KIT's Campus North. The results of these studies have been published in the journal Proceedings of the National Academy of Sciences.

Can cloud formation, precipitation or thunderstorms be influenced by laser light irradiation? This issue has been investigated by researchers from KIT's Institute for Meteorology and Climate Research -- Atmospheric Aerosol Research (IMK-AAF), Freie Universitδt Berlin, and the University of Geneva. The objective of the studies conducted by head of IMK-AAF Professor Thomas Leisner was to find out whether and in how far laser light and plasma can influence cloud formation.

For their investigations, the researchers used the facility AIDA (Aerosol Interactions and Dynamics in the Atmosphere) on KIT's Campus North and the mobile laser lab "Teramobile" developed in Geneva and Berlin. AIDA offers unique possibilities of studying aerosol and cloud processes under atmospheric conditions and can simulate all temperature and pressure conditions occurring in the lower and middle atmosphere.

The "Teramobile" generates high-intensity laser light pulses. Unlike normal laser light, these pulses propagate in a specific way in the atmosphere. "Due to nonlinear optical effects, these laser pulses kind of produce their own light guides, thus remaining sharply focused over long distances even if they would normally be dissipated by airborne particles and atmospheric opacity," explains Professor Thomas Leisner. A current-conducting plasma channel forms as the air gets ionized along the laser beam.

Effects of plasma channels on ice formation or precipitation processes could not be proved in typical storm clouds, where ice crystals and subcooled water droplets coexist. In high cirrus clouds, which consist purely of ice crystals, the researchers, however, came across a surprisingly strong reaction to laser irradiation: As described in PNAS, the laser pulses increase the number of ice particles by up to a factor of 100 within only a few seconds. The fact that, in that way, the optical density of the cirrostratus clouds is intensified by up to three orders of magnitude makes the clouds look much brighter. "The effect exerted on a typical thin sheet of cirrostratus clouds can be imagined to resemble laser-written contrails," Leisner says.

According to Professor Leisner, however, this laser effect on the atmosphere presently can only be applied in scientific cloud research. "Until clouds can be manipulated from the ground," the KIT climate researcher explains "much progress is required in laser technology."


Story Source:

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


Journal Reference:

  1. T. Leisner, D. Duft, O. Mohler, H. Saathoff, M. Schnaiter, S. Henin, K. Stelmaszczyk, M. Petrarca, R. Delagrange, Z. Hao, J. Luder, Y. Petit, P. Rohwetter, J. Kasparian, J.-P. Wolf, L. Woste. Laser-induced plasma cloud interaction and ice multiplication under cirrus cloud conditions. Proceedings of the National Academy of Sciences, 2013; DOI: 10.1073/pnas.1222190110

Cite This Page:

Karlsruhe Institute of Technology. "Laser-brightened cirrus clouds." ScienceDaily. ScienceDaily, 5 June 2013. <www.sciencedaily.com/releases/2013/06/130605104254.htm>.
Karlsruhe Institute of Technology. (2013, June 5). Laser-brightened cirrus clouds. ScienceDaily. Retrieved September 21, 2014 from www.sciencedaily.com/releases/2013/06/130605104254.htm
Karlsruhe Institute of Technology. "Laser-brightened cirrus clouds." ScienceDaily. www.sciencedaily.com/releases/2013/06/130605104254.htm (accessed September 21, 2014).

Share This



More Earth & Climate News

Sunday, September 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Climate Change Rally Held in India Ahead of UN Summit

Climate Change Rally Held in India Ahead of UN Summit

AFP (Sep. 20, 2014) — Some 125 world leaders are expected to commit to action on climate change at a UN summit Tuesday called to inject momentum in struggling efforts to tackle global warming. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
New Music With Recycled Instruments at Colombia Fest

New Music With Recycled Instruments at Colombia Fest

AFP (Sep. 19, 2014) — Jars, bottles, caps and even a pizza box, recovered from the trash, were the elements used by four musical groups at the "RSFEST2014 Sonorities Recycling Festival", in Colombian city of Cali. Duration: 00:49 Video provided by AFP
Powered by NewsLook.com
Raw: Wildfires in CA Burn Forest Asunder

Raw: Wildfires in CA Burn Forest Asunder

AP (Sep. 18, 2014) — An out-of-control Northern California wildfire has nearly 2,800 people from their homes as it continues to grow, authorities said Thursday. Authorities said a man has been arrested on suspicion of arson for starting the fire on Saturday. (Sept. 18) Video provided by AP
Powered by NewsLook.com
Raw: Elephant Undergoes Surgery in Tbilisi Zoo

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

AP (Sep. 18, 2014) — Grand the elephant has successfully undergone surgery to remove a portion of infected tusk at Tbilisi Zoo in Georgia. British veterinary surgeons used an electric drill to extract the infected piece. (Sept. 18) Video provided by AP
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:
from the past week

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