Featured Research

from universities, journals, and other organizations

Detecting clouds from both sides now

Date:
March 13, 2012
Source:
American Institute of Physics
Summary:
Researchers have developed a more precise method to detect the boundary between clouds and clear air, by exploiting the swinging motions of a weather balloon and its payload.

"Bows and flows of angel hair, and ice cream castles in the air;" we've looked at clouds that way. But the interface between clouds and clear air isn't as well-defined as these imaginative shapes might lead us to believe. Detecting that hazy line can help scientists to better understand the processes that lead to cloud formation, which is important for good weather forecasts and climate modeling. Now atmospheric scientists from the University of Reading in the United Kingdom have designed a sunlight-measuring tool that uses the natural swinging and spinning of a rising weather balloon to distinguish clouds from clear air and may provide higher-resolution measurements of cloud boundaries than is currently possible.

The researchers describe their device in a paper published in the American Institute of Physics' journal Review of Scientific Instruments.

Traditional cloud detection using weather balloons relies on measurements of temperature and relative humidity. The Reading researchers reasoned that they could sense clouds optically, using a simple and inexpensive design: a light sensor carried on a weather balloon. This sensor responds to the intensity of light, producing a maximum reading when pointing directly at the Sun in clear air but reduced readings at oblique angles to the Sun. As the sensor swings beneath a moving balloon, its orientation to the Sun changes continually, resulting in large fluctuations in the sensor's light intensity readings in cloudless conditions. But inside a cloud -- where light intensity is roughly the same in all directions -- the fluctuations become much smaller. The team showed that cloud edges could be detected by looking for an abrupt change in the size of these fluctuations.

Laboratory experiments demonstrated that the new instrument worked consistently over the wide range of temperatures that weather balloons encounter. In test flights, the optical technique was able to detect cloud boundaries with greater precision than traditional relative humidity measurements alone. Though this method works best to detect the upper boundaries of clouds, the researchers say that the new system could also be used to determine lower boundaries of clouds in broken cloud conditions or for high-level clouds.


Story Source:

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


Journal Reference:

  1. Keri A. Nicoll and Giles Harrison. Balloon-borne disposable radiometer for cloud detection. Review of Scientific Instruments, 2012

Cite This Page:

American Institute of Physics. "Detecting clouds from both sides now." ScienceDaily. ScienceDaily, 13 March 2012. <www.sciencedaily.com/releases/2012/03/120313092056.htm>.
American Institute of Physics. (2012, March 13). Detecting clouds from both sides now. ScienceDaily. Retrieved July 29, 2014 from www.sciencedaily.com/releases/2012/03/120313092056.htm
American Institute of Physics. "Detecting clouds from both sides now." ScienceDaily. www.sciencedaily.com/releases/2012/03/120313092056.htm (accessed July 29, 2014).

Share This




More Earth & Climate News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Climate Change Could Cost Billions, According To White House

Climate Change Could Cost Billions, According To White House

Newsy (July 29, 2014) A report from the White House warns not curbing greenhouse gas emissions could cost the U.S. billions. Video provided by Newsy
Powered by NewsLook.com
Climate Change Could Cost Billions According To White House

Climate Change Could Cost Billions According To White House

Newsy (July 29, 2014) A report from the White House warns not curbing greenhouse gas emissions could cost the U.S. billions. Video provided by Newsy
Powered by NewsLook.com
Jane Goodall Warns Great Apes Face Extinction

Jane Goodall Warns Great Apes Face Extinction

AFP (July 29, 2014) The world's great apes face extinction within decades, renowned chimpanzee expert Jane Goodall warned Tuesday in a call to arms to ensure man's closest relatives are not wiped out. Duration: 00:58 Video provided by AFP
Powered by NewsLook.com
Rat Infestation at Paris' Tuileries Garden

Rat Infestation at Paris' Tuileries Garden

AFP (July 29, 2014) An infestation of rats is causing concern among tourists at Paris' most famous park -- the Tuileries garden next to the Louvre Museum. Duration: 00:54 Video provided by AFP
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