Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Hurricane Forecasters Adopt NCAR Radar Technique

11.04.2008
The National Hurricane Center will implement a new technique this summer, developed by researchers at the National Center for Atmospheric Research (NCAR) and the Naval Research Laboratory (NRL), to continually monitor landfalling storms in the United States.

The system, which relies on existing coastal Doppler radars, provides details on hurricane winds and central pressure every six minutes, indicating whether a hurricane is gathering strength in its final hours before reaching shore.

The technique, known as VORTRAC (Vortex Objective Radar Tracking and Circulation), was successfully tested by the National Hurricane Center last year.

"VORTRAC will enable hurricane specialists, for the first time, to continually monitor the trend in central pressure as a dangerous storm nears land," says NCAR scientist Wen-Chau Lee. "With the help of VORTRAC, vulnerable communities can be better informed of sudden changes in hurricane intensity."

Lee collaborated with NRL's Paul Harasti and NCAR's Michael Bell to develop VORTRAC. Funding came primarily from the National Science Foundation and the National Oceanic and Atmospheric Administration. The NHC is part of NOAA's National Weather Service.

One of VORTRAC's strengths is that it can use radar data to estimate the barometric pressure at the center of a hurricane, a key measure of its intensity.

"VORTRAC allows us to take the wind measurements from the radar, turn the crank, and have a central pressure drop out of a calculation," says Colin McAdie, a meteorologist at NHC. "This will be a valuable addition to the tools available to the forecaster."

Avoiding surprises
Rapidly intensifying storms can catch vulnerable coastal areas by surprise. Last year, Hurricane Humberto struck near Port Arthur, Texas, after unexpectedly strengthening from a tropical depression to a hurricane in less than 19 hours. In 2004, Hurricane Charley's top winds increased from 110 to 145 miles per hour (about 175 to 235 kilometers per hour) in just six hours as the storm neared Florida's southwest coast.

Lee and his collaborators applied VORTRAC retroactively to the two hurricanes and found that the technique would have accurately tracked their quick bursts in intensity.

"VORTRAC has demonstrated that it can capture sudden intensity changes in potentially dangerous hurricanes in the critical time period when these storms are nearing land," Bell says.

New data from existing radars
VORTRAC uses the Doppler radar network established by NOAA in the 1990s. About 20 of these radars are scattered along the Gulf and Atlantic coastlines from Texas to Maine. Each radar can measure winds blowing toward or away from it, but no single radar could provide an estimate of a hurricane's rotational winds and central pressure until now.

The VORTRAC team developed a series of mathematical formulas that combine data from a single radar near the center of a landfalling storm with general knowledge of Atlantic hurricane structure in order to map the approaching system's rotational winds. VORTRAC also infers the barometric pressure in the eye of the hurricane, a very reliable index of its strength.

"By merging several techniques, we can now provide a missing link in short-term hurricane prediction," Harasti says.

Forecasters using VORTRAC can update information about a hurricane each time a NOAA Doppler radar scans the storm, which can be as often as about every six minutes. Without such a technique, forecasters would need at least two coastal radars in close proximity to each other in order to obtain the same information. But most of the network's radars are too far apart to qualify.

Each radar can sample conditions out to about 120 miles. This means VORTRAC can track an incoming hurricane for at least several hours, and possibly even as long as a day or more, depending on the storm's speed, trajectory, and size.

To monitor the winds of a landfalling hurricane, forecasters now rely on aircraft to drop instrument packages into the storm that gather data on winds and pressure. Due to flight logistics, the aircraft can take readings no more than every hour or two, which means that a sudden drop in barometric pressure, and the accompanying increase in winds, may be difficult to anticipate.

In time, VORTRAC may also help improve long-range hurricane forecasts by using data from airborne Doppler radars or spaceborne radars to produce detailed information about a hurricane that is far out to sea. Forecasters could input the data to computer models to improve three- and five-day forecasts.

In addition, many nations along the Pacific Rim and Indian Ocean have their own emerging Doppler radar networks. Those nations, which are vulnerable to tropical cyclones, may also be able to make use of VORTRAC.

David Hosansky | EurekAlert!
Further information:
http://www.ucar.edu

More articles from Information Technology:

nachricht Construction of practical quantum computers radically simplified
05.12.2016 | University of Sussex

nachricht UT professor develops algorithm to improve online mapping of disaster areas
29.11.2016 | University of Tennessee at Knoxville

All articles from Information Technology >>>

The most recent press releases about innovation >>>

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

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>