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 Impacts of mass coral die-off on Indian Ocean reefs revealed
21.02.2017 | University of Exeter

nachricht How much biomass grows in the savannah?
16.02.2017 | Friedrich-Schiller-Universität Jena

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Impacts of mass coral die-off on Indian Ocean reefs revealed

21.02.2017 | Earth Sciences

Novel breast tomosynthesis technique reduces screening recall rate

21.02.2017 | Medical Engineering

Use your Voice – and Smart Homes will “LISTEN”

21.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>