Featured Research

from universities, journals, and other organizations

Dual radar storm analysis technique works even with one

Date:
July 29, 2013
Source:
University of Alabama Huntsville
Summary:
Scientists can study how supercell thunderstorms work by using the data from just one Doppler radar unit and an analysis technique called synthetic dual-Doppler (SDD) that normally requires two.

Scientists may be able to better study how supercell thunderstorms work by using the data from just one Doppler radar unit and an analysis technique called synthetic dual-Doppler (SDD) that normally requires two, according to research done by a doctoral candidate at The University of Alabama in Huntsville (UAH).

Related Articles


Student Todd Murphy teamed with UAH atmospheric science professor Dr. Kevin Knupp to make one of the first comprehensive analyses of cold season supercells using only one Doppler radar with the application of the SDD analysis technique. The SDD technique allows researchers to examine the winds inside supercells in three dimensions.

Doppler radar works by sending a beam of electronic radiation that is tuned to a precise frequency at an object. The beam is then reflected back to a receiver. By using a phenomenon known as the Doppler effect, the frequency of the beam when it went out and the altered frequency of it when it returns can be used to calculate the movement of the object.

When developed in the late 1960s and refined in the 1970s, the SDD analysis used one such radar unit for the data needed to provide insights into the dynamic and thermodynamic quantities of a storm and measure wind speed and direction.

However, the ability of SDD to peer inside super-cells can be limited because the storms first must be close enough to radar facilities to be detectable.

"This is certainly a technique that will only work in certain cases," Murphy said. He has personally experienced the limitations when attempting to position UAH's Mobile Alabama X-band (MAX) truck to collect data on approaching storms.

"In the Southeast, with our topography and the trees we have, it is really difficult to position MAX."

Data from the widespread outbreak of cold season supercell storms on Super Tuesday in 2008 provided an opportunity for Murphy and Dr. Knupp to examine using the SDD technique with readings from single Doppler radar facilities.

Nighttime supercells on Super Tuesday 2008 were so widespread that in Tennessee, one in near Memphis and one near Nashville were close enough to single Doppler radar facilities for information about the storms to be obtained. Murphy and Dr. Knupp subjected the data from those single radar facilities to the SDD analysis technique.

"We were trying to find a new way to look at storms," said Murphy. "We feel like with this research, we proved that you can use just one radar source and the synthetic dual-Doppler radar technique to retrieve the winds in supercell thunderstorms.

"The SDD technique allows us to retrieve the three-dimensional wind components of a storm," he said. "It provides us with a lot more insight into what makes up a storm, including data on the vorticity (spin) of a supercell."

Researchers can see what's going on inside storms from about 500 meters off the ground and higher, so SDD provides information on the mid- and upper-level factors that are in turn spawning tornadoes on the ground.

"What we are really looking at is the mesocyclone, or the large movements occurring in the storm," Murphy said. Mesocyclones are huge vortexes of air moving around a vertical axis within a thunderstorm.

Because the radar got better data from the Nashville storm, it was the primary focus of the study. Its structure was very similar to low-top supercells that commonly are spawned as bands surrounding hurricanes, Murphy said.

Murphy's data also affirmed the importance of strong rear flank downdraft (RFD) in the formation of tornadoes. RFDs are the downdraft winds that occur in the trailing portion of the comma-like hook that is typical of storms that spawn tornadoes.

"Some previous research had shown RFD to be important in tornadogenesis," Murphy said. "The findings here do agree with the previous research that RFD is important."

Next, Murphy plans to publish a paper that is a large-scale view of the contributing factors of the Super Tuesday 2008 event as a whole.


Story Source:

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


Cite This Page:

University of Alabama Huntsville. "Dual radar storm analysis technique works even with one." ScienceDaily. ScienceDaily, 29 July 2013. <www.sciencedaily.com/releases/2013/07/130729082727.htm>.
University of Alabama Huntsville. (2013, July 29). Dual radar storm analysis technique works even with one. ScienceDaily. Retrieved December 21, 2014 from www.sciencedaily.com/releases/2013/07/130729082727.htm
University of Alabama Huntsville. "Dual radar storm analysis technique works even with one." ScienceDaily. www.sciencedaily.com/releases/2013/07/130729082727.htm (accessed December 21, 2014).

Share This


More From ScienceDaily



More Earth & Climate News

Sunday, December 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Lava on Track to Hit Hawaii Market

Raw: Lava on Track to Hit Hawaii Market

AP (Dec. 19, 2014) Lava from an active volcano on Hawaii's Big Island slowed slightly but stayed on track to hit a shopping center in the small town of Pahoa. (Dec. 19) Video provided by AP
Powered by NewsLook.com
Birds Might Be Better Meteorologists Than Us

Birds Might Be Better Meteorologists Than Us

Newsy (Dec. 19, 2014) A new study suggests a certain type of bird was able to sense a tornado outbreak that moved through the U.S. a day before it hit. Video provided by Newsy
Powered by NewsLook.com
Navy Unveils Robot Fish

Navy Unveils Robot Fish

Reuters - Light News Video Online (Dec. 18, 2014) The U.S. Navy unveils an underwater device that mimics the movement of a fish. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
Arctic Warming Twice As Fast As Rest Of Planet

Arctic Warming Twice As Fast As Rest Of Planet

Newsy (Dec. 18, 2014) The Arctic is warming twice as fast as the rest of the planet, thanks in part to something called feedback. 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