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).

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 July 25, 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 July 25, 2014).

Share This




More Earth & Climate News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Goma Cheese Brings Whiff of New Hope to DRC

Goma Cheese Brings Whiff of New Hope to DRC

Reuters - Business Video Online (July 24, 2014) The eastern region of the Democratic Republic of Congo, mainly known for conflict and instability, is an unlikely place for the production of fine cheese. But a farm in the village of Masisi, in North Kivu is slowly transforming perceptions of the area. Known simply as Goma cheese, the Congolese version of Dutch gouda has gained popularity through out the region. Ciara Sutton reports. Video provided by Reuters
Powered by NewsLook.com
Bill Gates: Health, Agriculture Key to Africa's Development

Bill Gates: Health, Agriculture Key to Africa's Development

AFP (July 24, 2014) Health and agriculture development are key if African countries are to overcome poverty and grow, US software billionaire Bill Gates said Thursday, as he received an honourary degree in Ethiopia. Duration: 00:36 Video provided by AFP
Powered by NewsLook.com
Higgins Breaks Record at Mt. Washington

Higgins Breaks Record at Mt. Washington

Driving Sports (July 24, 2014) Subaru Rally Team USA drivers David Higgins and Travis Pastrana face off against a global contingent of racers at the annual Mt. Washington Hillclimb in New Hampshire. Includes exclusive in-car footage from Higgins' record attempt. Video provided by Driving Sports
Powered by NewsLook.com
Storm Kills Three, Injures 20 at Virginia Campground

Storm Kills Three, Injures 20 at Virginia Campground

Reuters - US Online Video (July 24, 2014) A likely tornado tears through an eastern Virginia campground, killing three and injuring at least 20. Linda So 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:
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