Featured Research

from universities, journals, and other organizations

Researchers develop technique to help pollution forecasters see past clouds

Date:
July 10, 2012
Source:
University of Iowa
Summary:
Scientists have created a technique to help satellites "see" through the clouds and better estimate the concentration of pollutants, such as soot.

This image shows two MODIS-Aqua products for Oct. 17, 2008, over the persistent Southeast Pacific stratocumulus deck, off the coasts of Chile and Peru. UI researchers and their colleagues have developed a new technique to evaluate how aerosol pollutants affect clouds, thereby giving scientists the ability to examine clouds and determine particle concentrations in the atmosphere below.
Credit: Satellite retrievals courtesy of NASA Goddard Space Flight Center; image courtesy of Pablo Saide, Greg Carmichael, Scott Spak, Matthew Janechek, and Nicholas Thornburg, University of Iowa.

Until now, scientists who study air pollution using satellite imagery have been limited by weather. Clouds, in particular, provide much less information than a sunny day.

University of Iowa scientists have created a technique to help satellites "see" through the clouds and better estimate the concentration of pollutants, such as soot. The finding is important, because, like GPS systems, clouds block remote-sensing satellites' ability to detect, and thus calculate, the concentration of pollution nearer to the ground. This includes particles (commonly known as soot) that reduce air quality and affect weather and climate.

The results of the study are published July 9 in the online early edition of the journal Proceedings of the National Academy of Sciences (PNAS).

This image shows two MODIS-Aqua products for Oct. 17, 2008, over the persistent Southeast Pacific stratocumulus deck, off the coasts of Chile and Peru. UI researchers and their colleagues have developed a new technique to evaluate how aerosol pollutants affect clouds, thereby giving scientists the ability to examine clouds and determine particle concentrations in the atmosphere below. Satellite retrievals courtesy of NASA Goddard Space Flight Center; image courtesy of Pablo Saide, Greg Carmichael, Scott Spak, Matthew Janechek, and Nicholas Thornburg, University of Iowa.

"Particles in the atmosphere (aerosols) interact with clouds changing their properties. With this technique, we can use remote sensing observations from satellites to estimate these cloud properties in order to correct predictions of particle concentrations. This is possible due to a numerical model that describes these aerosol-clouds interactions," says Pablo Saide, environmental engineering doctoral student and researcher at the UI Center for Global and Regional Research (CGRER).

Scott Spak, co-author and assistant professor of civil and environmental engineering in the UI College of Engineering, adds that the new technique is expected to find immediate application across a wide range of activities. Examples include air quality forecasting, numerical weather prediction, climate projections, oceanic and anthropogenic emissions estimation, and health effects studies.

But the ability to see pollution "through the clouds" is also expected to have "on the ground" health results.

"Unlike previous methods, this technique can directly improve predictions of near-surface, fine-mode aerosols -- such as coal-fired electric generating plants and wood-fueled cooking fires -- responsible for human health impacts and low-cloud radiative forcing (solar heating)," says Greg Carmichael, co-author, professor of chemical and biochemical engineering, and CGRER co-director. "This technique is also complementary to previous methods used, allowing the observing system to 'see aerosols' even under cloudy conditions."

Here's how the technique works:

  • Existing weather satellites observe warm, single-layer clouds, such as the stratocumulus clouds that form off the west coasts of Africa, North America, and South America. These clouds are thought to be the main factors contributing to climate cooling.
  • Researchers calculate the number of droplets in the clouds using the satellite data, which are compared to a model estimate provided by the UI program.
  • As airborne particles interact with clouds changing their properties, model estimates of particles are corrected so that the model will generate a better agreement with the satellite number of droplets.
  • Particles interacting with clouds are usually below clouds, thus, in some cases, the model corrections can be attributed to humanmade emissions.

The researchers conducted their study using National Science Foundation (NSF) aircraft measurements to make simultaneous cloud and particle observations, which verified satellite observations and the mathematical formulas used to determine the pollution concentrations in the air.

All three UI researchers agree that their new technique for seeing through clouds to make ground observations is likely to generate growing interest as the need to infer ground air pollution levels, and the need to mitigate the human hazards posed, grows larger.

In addition to UI researchers, paper co-authors include Patrick Minnis of NASA Langley Research Center, Hampton, Va., and Kirk Ayers of Science Systems and Applications Inc., Hampton, Va.

The PNAS article is titled "Improving aerosol distributions below clouds by assimilating satellite-retrieved cloud droplet number."

The research was funded by NSF and NASA.


Story Source:

The above story is based on materials provided by University of Iowa. The original article was written by Gary Galluzzo. Note: Materials may be edited for content and length.


Journal Reference:

  1. P. E. Saide, G. R. Carmichael, S. N. Spak, P. Minnis, J. K. Ayers. Improving aerosol distributions below clouds by assimilating satellite-retrieved cloud droplet number. Proceedings of the National Academy of Sciences, 2012; DOI: 10.1073/pnas.1205877109

Cite This Page:

University of Iowa. "Researchers develop technique to help pollution forecasters see past clouds." ScienceDaily. ScienceDaily, 10 July 2012. <www.sciencedaily.com/releases/2012/07/120710172156.htm>.
University of Iowa. (2012, July 10). Researchers develop technique to help pollution forecasters see past clouds. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2012/07/120710172156.htm
University of Iowa. "Researchers develop technique to help pollution forecasters see past clouds." ScienceDaily. www.sciencedaily.com/releases/2012/07/120710172156.htm (accessed October 22, 2014).

Share This



More Earth & Climate News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

San Diego Zoo's White Rhinos Provide Hope for the Critically Endangered Species

San Diego Zoo's White Rhinos Provide Hope for the Critically Endangered Species

Reuters - Light News Video Online (Oct. 22, 2014) — The pair of rare white northern rhinos bring hope for their species as only six remain in the world. Elly Park reports. Video provided by Reuters
Powered by NewsLook.com
Trick-or-Treating Banned Because of Polar Bears

Trick-or-Treating Banned Because of Polar Bears

Buzz60 (Oct. 21, 2014) — Mother Nature is pulling a trick on the kids of Arviat, Canada. As Mara Montalbano (@maramontalbano) tells us, the effects of global warming caused the town to ban trick-or-treating this Halloween. Video provided by Buzz60
Powered by NewsLook.com
Traditional Farming Methods Gaining Ground in Mali

Traditional Farming Methods Gaining Ground in Mali

AFP (Oct. 20, 2014) — He is leading a one man agricultural revolution in Mali - Oumar Diatabe uses traditional farming methods to get the most out of his land and is teaching others across the country how to do the same. Duration: 01:44 Video provided by AFP
Powered by NewsLook.com
How Detroit's Money Woes Led To U.N.-Condemned Water Cutoffs

How Detroit's Money Woes Led To U.N.-Condemned Water Cutoffs

Newsy (Oct. 20, 2014) — The United Nations says water is a human right, but should it be free? Detroit has cut off water to residents who can't pay, and the U.N. isn't happy. Video provided by Newsy
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