Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Rapid-scanning doppler on wheels keeps pace with twisters

02.06.2005


A multibeam Doppler radar that can scan tornadic storms every 5 to 10 seconds is prowling the Great Plains through June 30 in search of its first close-up tornado. Engineers at the National Center for Atmospheric Research in Boulder helped build the Rapid-Scan Doppler on Wheels (DOW).



Together with a powerful analysis technique pioneered by NCAR scientist Wen-Chau Lee, the radar--newly enhanced for its first full spring of thunderstorm tracking--promises the most complete picture to date of tornado evolution.

The radar is being deployed this spring, along with another DOW unit, by NCAR scientific visitor Joshua Wurman (Center for Severe Weather Research, or CSWR) from a temporary base in Hays, Kansas.


Most Doppler radars transmit only a single beam, which takes about 5 minutes to make the vertical and horizontal scans needed for a three-dimensional storm portrait. But tornadoes can develop or dissipate in a minute or less. With its 5- to 10-second resolution and close range, the Rapid-Scan DOW can detail these critical steps in tornado behavior.

"The development of the Rapid-Scan DOW is an important advancement for meteorological research," said Steve Nelson, director of NSF’TMs physical and dynamic meteorology program, which funded the radar’TMs development. "The new radar will result in unique measurements of rapidly evolving meteorological phenomena such as tornadoes."

The first DOW was deployed in 1995. Since then, Wurman’TMs group has collected data on roughly 100 tornadoes, intercepted the eyes of eight hurricanes, and profiled forest fires. On May 3, 1999, DOW measured a world-record wind speed of 301 miles per hour just above ground level in an Oklahoma tornado.

As part of a $1.6 million NSF grant, Wurman and Curtis Alexander (University of Oklahoma) are analyzing the entire DOW data set on tornadoes to uncover new information, such as how closely tornado diameters are correlated with top wind speeds. Other scientists at OU and Pennsylvania State University will also carry out DOW analyses through the grant. "We can’TMt answer even the basic questions about typicalTM tornadoes right now, such as how strong their winds are," says Wurman. "By looking at these 100 cases, we hope to understand the distribution of features across many types of tornadoes." These findings could be compared to storm types to help produce better warnings, Wurman adds.

Wurman and Lee plan to select a few tornadoes for more in-depth study. They’TMll use a technique called velocity track display (VTD), originally developed by Lee for hurricane studies, that allows scientists to extract three-dimensional winds using data from a single Doppler radar. The two scientists have already used VTD with DOW data to analyze a large and intense tornado that struck Mulhall, Oklahoma, in 1999. They discovered a central downdraft, similar to the eye of a hurricane, surrounded by a ring of updrafts blowing at near-hurricane force, with multiple small vortices rotating around this ring.

The structure found in the Mulhall tornado had been observed for many years in lab experiments and computer models, but it had never been verified by radar data. Lee expects to find a simpler structure in weak tornadoes, without the central downdraft observed in Mulhall.

"We want to use DOW data to analyze more tornadoes of different sizes and intensities and see how they compare to our laboratory work and our model results," Lee says.

Dubbed ROTATE-05, the field work is supported by the National Geographic Society. Design and construction of the Rapid-Scan DOW is funded by the National Science Foundation, which is also NCAR’TMs primary sponsor.

Opinions, findings, conclusions, or recommendations expressed in this publication do not necessarily reflect the views of the National Science Foundation.

Anatta | EurekAlert!
Further information:
http://www.cswr.org
http://www.ucar.edu

More articles from Ecology, The Environment and Conservation:

nachricht Upcycling 'fast fashion' to reduce waste and pollution
03.04.2017 | American Chemical Society

nachricht Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

NASA's Fermi catches gamma-ray flashes from tropical storms

25.04.2017 | Physics and Astronomy

Researchers invent process to make sustainable rubber, plastics

25.04.2017 | Materials Sciences

Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017

25.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>