Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Stay south of thunderstorm paths, says Purdue scientist

18.11.2003


Damaging winds can occur in previously overlooked places within a thunderstorm, according to a Purdue University earth scientist. The finding could help meteorologists save lives and reduce injuries by issuing more accurate storm warnings.



Based on new data on the behavior of winds in developing storms, Purdue’s Robert J. "Jeff" Trapp has found that the north side of a storm front can host cyclonic winds that are more intense than those at the storm’s "apex," or leading point, which is generally thought to usher in the strongest winds. These newly found whirlpools of wind can be miles wide and create gusts reaching 100 miles per hour.

"On average, whatever lies in the path of the apex suffers wind damage," said Trapp, who is an associate professor of earth science in Purdue’s School of Science. "However, it’s not the whole story. Meteorologists should be aware of these other vortices in order to present the full picture of a storm front."


The study appears in this month’s Monthly Weather Review. It was co-authored by Morris Weisman of the National Center for Atmospheric Research (NCAR) in Boulder, Colo., where the team conducted computer simulations that contributed to their research.

Using a supercomputer at NCAR, the team initially set out to look at the tornadoes that can form along a front’s leading edge, often called the squall line. These tornadoes are particularly dangerous because of how difficult they are to predict. But what the researchers found in their simulations were much larger vortices that can form at the squall line north of the apex.

"If you’ve watched a weather program’s time-lapse animation of a storm’s development, you’ve seen a squall line as a long, generally north-to-south bank of precipitation," Trapp said. "While the edges of these fronts can resemble straight lines at first, as storms grow in strength a front can look more like a boomerang, with the storm’s apex forming the ’point.’"

Trapp said it is north of this "point" that the vortices generally develop.

"These strong, spinning winds can do great damage over large areas," Trapp said. "They are not tornadoes themselves, but tornadoes can develop from them. We plan to research how this happens as well."

The vortices form only on the north side of the apex because of the spinning of the earth, which tends to deter vortices from forming on the south side.

"The effect of this force, called the Coriolis force, is usually neglected in discussions of thunderstorms," Trapp said. "But out work shows that it is critical to the formation of the damaging vortices in squall lines."

After seeing the vortices form in the simulation, Trapp, Weisman and numerous colleagues across the country observed them in many storms in the Midwest during a recent field program called BAMEX. Trapp said he thinks the reason these vortices have been overlooked in the past is because tracks of storm damage are seldom related back to weather radar images, particularly Doppler radar images, which can indicate the presence of vortices. Special data collected during the BAMEX program will provide Trapp and his colleagues the opportunity to do just that.

Trapp said existing technology could be modified to predict this newly found danger.

"The Doppler radars in use around the U.S., known as ’Nexrads,’ can be used to detect these vortices," he said. "It’s just a matter of adapting the computer software that sorts through the Nexrad data to this problem."

The next step for Trapp and Weisman is to head back to the simulator and attempt to create more sophisticated computer models of the vortices.

"We still have a lot to learn," he said. "Our explanations need to be modified to take into account all the possible real-world factors that we neglected in our initial models. Until we have more specific answers, the most useful thing we can do is simply make meteorologists aware of what could happen and tell them to be on the lookout for it."

This study was funded in part by a grant from the National Science Foundation and by the National Severe Storms Laboratory.


Writer: Chad Boutin, (765) 494-2081, cboutin@purdue.edu
Source: Robert "Jeff" Trapp, (765) 496-6661, jtrapp@purdue.edu

Chad Boutin | Purdue News
Further information:
http://news.uns.purdue.edu/UNS/html4ever/031117.Trapp.vortex.html

More articles from Earth Sciences:

nachricht Large-Mouthed Fish Was Top Predator After Mass Extinction
26.07.2017 | Universität Zürich

nachricht Strength of tectonic plates may explain shape of the Tibetan Plateau, study finds
25.07.2017 | University of Illinois at Urbana-Champaign

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

 
Latest News

CCNY physicists master unexplored electron property

26.07.2017 | Physics and Astronomy

Molecular microscopy illuminates molecular motor motion

26.07.2017 | Life Sciences

Large-Mouthed Fish Was Top Predator After Mass Extinction

26.07.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>