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 Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen

nachricht A new indicator for marine ecosystem changes: the diatom/dinoflagellate index
21.08.2017 | Leibniz-Institut für Ostseeforschung Warnemünde

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: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

Im Focus: Fast, convenient & standardized: New lab innovation for automated tissue engineering & drug

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...

Im Focus: Silencing bacteria

HZI researchers pave the way for new agents that render hospital pathogens mute

Pathogenic bacteria are becoming resistant to common antibiotics to an ever increasing degree. One of the most difficult germs is Pseudomonas aeruginosa, a...

Im Focus: Artificial Enzymes for Hydrogen Conversion

Scientists from the MPI for Chemical Energy Conversion report in the first issue of the new journal JOULE.

Cell Press has just released the first issue of Joule, a new journal dedicated to sustainable energy research. In this issue James Birrell, Olaf Rüdiger,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

IVAM’s LaserForum visits the Swiss canton of St. Gallen with the topic ultrashort pulse lasers

06.09.2017 | Event News

 
Latest News

The Wadden Sea and the Elbe Studied with Zeppelin, Drones and Research Ships

19.09.2017 | Earth Sciences

Digging sensors out of an efficiency hole

19.09.2017 | Materials Sciences

Solar wind impacts on giant 'space hurricanes' may affect satellite safety

19.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>