Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

ERS-2 has ringside view of Hurricane Wilma’s violent winds

25.10.2005


As Hurricane Wilma barrels towards the Florida coast, a last-minute acquisition by a unique instrument aboard ERS-2 is helping strengthen weather forecasters’ final predictions of its future course and strength.



The ERS-2 radar scatterometer data shown here was acquired by the satellite on 04:30 UTC this morning (06:30 CEST), then relayed via the ground station of the Center for Southeastern Tropical Advanced Remote Sensing (CSTARS) at the University of Miami to be speedily processed by the Royal Netherlands Meteorological Institute (KNMI), being made available to forecasters to analyse within the hour.

"ERS scatterometer data are very useful to correct position and strength of tropical cyclones in numerical weather analyses and prediction," said Ad Stoffelen of the KNMI. "For its application one must note that each scatterometer wind is measured in a wind cell of about 50 by 50 km.


"For this case the maximum mean wind measured over such extended area is about 100km/hour. Given a tropical cyclone model, meteorologists know that local sustained winds are typically 50% larger, and gusts may reach speeds even three times larger."

Dr Hans C. Grabar of CSTARS added that as Wilma has yet to make landfall, the scatterometer data would be swiftly passed to the US National Hurricane Center "which will aid in their advisories setting marine conditions and predicting the strength of winds at landfall".

The payload of ERS-2 – ESA’s veteran Earth Observation satellite launched back in 1995 - includes the only radar scatterometer currently flying capable of peering through the thick clouds and rain swirling around Wilma to chart the underlying wind fields powering the storm.

This instrument works by firing a trio of high-frequency radar beams down to the ocean, then analysing the pattern of backscatter reflected up again. Wind-driven ripples on the ocean surface modify the radar backscatter, and as the energy in these ripples increases with wind velocity, so backscatter increases as well. Scatterometer results enable measurements of not only wind speed but also direction across the water surface.

What makes ERS-2’s scatterometer especially valuable is that its C-band radar frequency is almost unaffected by heavy rain, so it can return useful wind data even from the heart of the fiercest storms – and is the sole scatterometer of this type currently in orbit.

As well as being processed by KMNI, scatterometer data are also routinely assimilated by the European Centre for Medium-Range Weather Forecasting (ECMWF) into their advanced numerical models used for meteorological predictions.

Wilma struck the Mexican coast on Friday, but dampened down from a Category Four storm on the Saffir-Simpson Hurricane Scale down to a Category Two. Back over the open sea, the storm strengthened and sped up to a Category Three.

ESA’s scatterometer future

To maintain future continuity of scatterometer coverage, a new more advanced scatterometer instrument called ASCAT is part of the payload for ESA’s MetOp mission, currently due to launch in 2006.

Mariangela D’Acunto | alfa
Further information:
http://www.esa.int/esaEO/SEMBWW3J2FE_planet_0.html

More articles from Earth Sciences:

nachricht New research calculates capacity of North American forests to sequester carbon
16.07.2018 | University of California - Santa Cruz

nachricht Scientists discover Earth's youngest banded iron formation in western China
12.07.2018 | University of Alberta

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Machine-learning predicted a superhard and high-energy-density tungsten nitride

18.07.2018 | Materials Sciences

NYSCF researchers develop novel bioengineering technique for personalized bone grafts

18.07.2018 | Life Sciences

Why might reading make myopic?

18.07.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>