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 In times of climate change: What a lake’s colour can tell about its condition
21.09.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)

nachricht Did marine sponges trigger the ‘Cambrian explosion’ through ‘ecosystem engineering’?
21.09.2017 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: LaserTAB: More efficient and precise contacts thanks to human-robot collaboration

At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.

Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

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...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | 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

 
Latest News

Fraunhofer ISE Pushes World Record for Multicrystalline Silicon Solar Cells to 22.3 Percent

25.09.2017 | Power and Electrical Engineering

Usher syndrome: Gene therapy restores hearing and balance

25.09.2017 | Health and Medicine

An international team of physicists a coherent amplification effect in laser excited dielectrics

25.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>