Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NASA Technology Captures Massive Hurricane Waves

27.09.2006
A hurricane's fury can be relentless, from frightening winds, to torrential rains and flooding. These storms also create enormous ocean waves that are hazardous to ships. And through storm surges of up to 30 feet the storms can demolish shoreline structures, erode beaches and wash out coastal roads.

As part of its activities to better understand Earth’s dynamic climate, NASA research is helping to increase knowledge about the behavior of hurricane waves. The NASA Scanning Radar Altimeter (SRA), designed to take measurements of the changing wave height and structure in and around hurricanes, flew through many storms on a National Oceanic and Atmospheric Administration (NOAA) WP-3D aircraft from 1998-2005. It captured unprecedented details on wave behavior that are helping improve sea height forecasts. Strong storms like Hurricane Bonnie in August 1998 - the first to be monitored by SRA - were found to produce severe ocean waves and dramatic changes in wave height and complexity over small distances.

The SRA measures waves by sweeping a radar beam across the ocean and measuring the distance to the sea at many points. Those distances are then subtracted from the aircraft altitude to produce a sea-surface elevation map that is displayed on a monitor in the aircraft.

While the flight portion of the SRA hurricane research program concluded with the 2005 hurricane season, the data gathered continue to help researchers develop and improve ocean wave computer models that simulate hurricane-generated ocean wave height, dominant wavelength, and wave direction.

These computer models allow wave behavior to be predicted at times and places where there are no observations. However, actual observations from SRA are essential because "they tell us how the wave field - the height, length and direction of waves in a given area – actually varies with a hurricane's wind speed, size, and forward motion so that we can improve the performance of the models that disaster managers and structural engineers rely on for guidance," said C. Wayne Wright, NASA Wallops Flight Facility, Wallops Island, Va.

Ongoing research efforts have shown that ocean wave height responds rapidly to changes in a storm's wind speed. But scientists believe the overall wave field is also driven by the size or radius of a storm's strongest winds, and its forward speed. In Hurricane Katrina in August 2005 the largest waves, up to 40 feet, were found near the strongest winds. In September 2004, scientists with the Naval Research Laboratory-Stennis Space Center, Bay St. Louis, Miss., measured a record-size ocean wave - a whopping 91 feet - when the eye wall of Hurricane Ivan passed over sensors in open water over the Gulf of Mexico.

"Ocean depth is another critical factor in wave height," said Edward Walsh, NASA Wallops Flight Facility, Wallops Island, Va. "Our observations from Hurricane Bonnie indicated that as soon as the waves encountered the continental shelf - the underwater extension of the coastal plain - their length began to shorten and they became steeper. As the water became shallow, wave height plummeted."

Similarly, with Hurricane Rita in September 2005, the wave height dropped dramatically and was only 9 feet when wave energy was lost due to the shoaling of water on the continental shelf - the process in which waves coming into shallow waters are slowed by friction and become closer together and steeper.

Fortunately, a storm's most massive waves usually decrease in size when they interact with the ocean's continental shelf and other land forms, like "barrier islands" that form a thin protective wall between the open sea and the mainland. The islands absorb the strongest waves, sheltering the mainland during large storms. But with powerful storms like Katrina, the constant battering of waves can take a toll on the land, leaving the islands reduced or gone altogether.

SRA's detailed and precise information, together with data to be gathered by a new operational SRA being built by NOAA to replace the NASA prototype, promises to provide additional insight into a hurricane's behavior. Such research is increasingly important as areas become more prone to higher storm surges as natural defenses like barrier islands and wetlands disappear.

Rob Gutro | EurekAlert!
Further information:
http://www.nasa.gov
http://www.nasa.gov/mission_pages/hurricanes/archives/2006/hurricane_waves.html

More articles from Earth Sciences:

nachricht NASA's AIM observes early noctilucent ice clouds over Antarctica
05.12.2016 | NASA/Goddard Space Flight Center

nachricht GPM sees deadly tornadic storms moving through US Southeast
01.12.2016 | NASA/Goddard Space Flight Center

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

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...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

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

High-precision magnetic field sensing

05.12.2016 | Power and Electrical Engineering

Construction of practical quantum computers radically simplified

05.12.2016 | Information Technology

NASA's AIM observes early noctilucent ice clouds over Antarctica

05.12.2016 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>