Featured Research

from universities, journals, and other organizations

NASA Technology Captures Massive Hurricane Waves

Date:
September 27, 2006
Source:
NASA/Goddard Space Flight Center
Summary:
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.

The Chandeleur Islands, a north-south oriented chain of low-lying islands located east of New Orleans, were severely damaged by recent hurricanes. The first image, taken in July 2001, shows narrow beaches, vegetated dunes, and marshes. The second image is of the same area on August 31, 2005, two days after Hurricane Katrina made landfall. The storm surge submerged the islands, stripped sand from the beaches, and eroded large sections of the marsh.
Credit: USGS

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.


Story Source:

The above story is based on materials provided by NASA/Goddard Space Flight Center. Note: Materials may be edited for content and length.


Cite This Page:

NASA/Goddard Space Flight Center. "NASA Technology Captures Massive Hurricane Waves." ScienceDaily. ScienceDaily, 27 September 2006. <www.sciencedaily.com/releases/2006/09/060926104518.htm>.
NASA/Goddard Space Flight Center. (2006, September 27). NASA Technology Captures Massive Hurricane Waves. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/2006/09/060926104518.htm
NASA/Goddard Space Flight Center. "NASA Technology Captures Massive Hurricane Waves." ScienceDaily. www.sciencedaily.com/releases/2006/09/060926104518.htm (accessed October 1, 2014).

Share This



More Earth & Climate News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: 12 More Bodies Found on Japan Volcano

Raw: 12 More Bodies Found on Japan Volcano

AP (Oct. 1, 2014) — A dozen more bodies were found Wednesday as Japanese rescuers resumed efforts to find survivors and retrieve bodies of those trapped by Mount Ontake's eruption. (Oct. 1) Video provided by AP
Powered by NewsLook.com
Cultural Learning In Wild Chimps Observed For The First Time

Cultural Learning In Wild Chimps Observed For The First Time

Newsy (Oct. 1, 2014) — Cultural transmission — the passing of knowledge from one animal to another — has been caught on camera with chimps teaching other chimps. Video provided by Newsy
Powered by NewsLook.com
Raw: Trapped Scientist Rescued from Cave in Peru

Raw: Trapped Scientist Rescued from Cave in Peru

AP (Oct. 1, 2014) — A Spanish scientist, who spent 12 days trapped about 1300 feet underground in a cave in Peru's remote Amazon region, was rescued on Tuesday. (Oct. 1) Video provided by AP
Powered by NewsLook.com
Earth Has Lost Half Its Vertebrate Wildlife Since 1970: WWF

Earth Has Lost Half Its Vertebrate Wildlife Since 1970: WWF

Newsy (Sep. 30, 2014) — A new study published by the World Wide Fund for Nature found that more than half of the world's wildlife population has declined since 1970. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins