Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Technology that measures sea level, helps predict EL Nino events, improved by new modeling

13.04.2006


A paper published today in the American Geophysical Union’s Journal of Geophysical Research-Oceans shows a method to recover valuable data from the primary tool used for measuring global sea level – satellite radar altimetry. Altimeter data are used, among other benefits, to monitor and predict the occurrence of events such as El Niño and La Niña – a coupled ocean-atmosphere phenomena that can alter global weather patterns.



Some six percent of global altimetry measurements are typically discarded because the instrument can’t get accurate readings in areas of ocean calm or “slicks” caused by a lack of wind and waves, or by surface films created by blooms of phytoplankton or oil spills. Because millions of altimeter measurements are made per year, that six percent translates into a huge amount of unused data.

The improvement comes from a modeling technique developed by scientists that should enhance and expand the number of altimeter measurements that NASA can collect – using the Jason-1 satellite – from the equatorial Pacific Ocean where El Niño events originate. Jason-1, launched in 2001, is a joint NASA/Centre National d’Études Spatiales or CNE (the French government space agency) mission.


Says co-author Doug Vandemark, now a radar engineer/oceanographer and research professor at the University of New Hampshire’s Institute for the Study of Earth, Oceans, and Space (EOS), “Every year our altimeters make something like 10 million ocean measurements so being able to recover at least a portion of that six percent gives us better information on sea-surface height. The percentage is much higher than six for calmer equatorial regions such as the Pacific, which tells us about where the bulge of water is that controls the El Niño.”

Picture the Pacific Ocean as a big bathtub. A bulge in the western end – created by warm water and winds – can set off an El Niño event by creating a wave that propagates very quickly along the equator from Asia towards the Americas, eventually inducing large water temperature changes along the coasts of South and North America. When the bulge makes its inevitable and slower return back, that’s a La Niña event.

Says the JGR paper’s lead author, Jean Tournadre of Laboratoire d’Océanographie Saptiale, Institut Français de Recherche pour l’Exploitation de la Mer, “Satellite altimetry has become a standard tool for ocean modeling and climatology studies.” He adds, “Altimeters provide precise measurements of sea-surface topography, the significant wave height, and the small-scale roughness of the sea surface.” Indeed, a radar altimeter can measure sea height down to one centimeter.

Altimetry works by sending 1,800 separate radar pulses per second down towards Earth from a height of some 800 kilometers and recording how long their echoes take to bounce back. The authors’ work with what Vandemark calls “the problematic subset of echoes from very smooth ocean areas” suggests that altimeters may now be able to estimate the spatial extent of these smooth areas as well and to recover more sea level estimates.

Vandemark notes that having more accurate equatorial Pacific Ocean measurements “provides agencies like NASA and NOAA more measurements for El Niño prediction and tracking.” NOAA, the National Oceanic and Atmospheric Administration, is responsible for forecasting El Niño events, just as its National Weather Service is responsible for weather forecasting and warnings.

Radar altimetry has been around for only 15 years and in that time has revolutionized the study of the ocean. Among its other scientific uses, altimetry is also used to monitor the ocean’s circulation patterns, glaciers, predict the strength of hurricanes, and measure river and lake levels worldwide.

To learn more about ocean surface topography from space, visit http://sealevel.jpl.nasa.gov.

David Sims | EurekAlert!
Further information:
http://sealevel.jpl.nasa.gov
http://www.unh.edu

More articles from Earth Sciences:

nachricht PR of MCC: Carbon removal from atmosphere unavoidable for 1.5 degree target
22.05.2018 | Mercator Research Institute on Global Commons and Climate Change (MCC) gGmbH

nachricht Monitoring lava lake levels in Congo volcano
16.05.2018 | Seismological Society of America

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Research reveals how order first appears in liquid crystals

23.05.2018 | Life Sciences

Space-like gravity weakens biochemical signals in muscle formation

23.05.2018 | Life Sciences

NIST puts the optical microscope under the microscope to achieve atomic accuracy

23.05.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>