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 Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel

nachricht Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)

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: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

'Lipid asymmetry' plays key role in activating immune cells

20.02.2018 | Life Sciences

MRI technique differentiates benign breast lesions from malignancies

20.02.2018 | Medical Engineering

Major discovery in controlling quantum states of single atoms

20.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>