Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

World Ocean Day: how satellites safeguard our waters

09.06.2005


Earth’s oceans are what make this a Blue Planet. Our seas influence the climate, produce most of the oxygen we breathe, serve as a means of transport and a major source of food and resources. Today’s World Ocean Day is a chance to learn more about the seas that surround us – and how satellite monitoring helps protect them.



Wednesday 8 June is the 13th annual World Ocean Day. Created in 1992 at the Earth Summit at Rio de Janeiro, World Ocean Day is an opportunity to celebrate our world ocean, its abundant life, and the ways we are all connected to the sea, no matter how far we live from its edge. More than 600 aquariums, zoos, museums and conservation organisations are participating in global activities today.

The ocean is no longer so abundant and clean as it once was: many of the world’s fisheries are in decline, coral ecosystems are deteriorating and fragile coastal habitats being choked by pollution. But today and every day, Earth Observation spacecraft continuously acquire data across the seven tenths of our planet covered by the sea.


These data increase our scientific understanding and support a range of environmental monitoring services in support of ocean conservation.

Global ocean temperature measurements

Space-based instruments measure sea surface temperature, which is important because it helps improve weather forecasting and is also a key indicator of the likely extent of future climate change – the oceans working like batteries that store incoming solar energy.

For example, the family of Along Track Scanning Radiometer (ATSR) sensors carried on ESA’s ERS and Envisat satellites have compiled a continuous dataset of ocean temperatures that stretches back 14 years that could be used to prove a heating trend beyond the range of natural variation.

An ambitious plan aims at merging all available sea surface temperature data including satellite sources into a worldwide high-resolution product known as the Global Ocean Data Assimilation Experiment (GODAE) High-Resolution Sea Surface Temperature Pilot Project (GHRSST-PP).

The European component of this global effort is an ESA activity called Medspiration, producing daily-updated high-resolution heat maps of European waters including the Mediterranean Sea.

Three-dimensional ocean mapping

The ever-changing topography of the ocean is also monitored from orbit. Radar imagery and scatterometer data reveal ocean waves and sea surface wind fields. Sea surface height is acquired with the Radar Altimeter (RA) family of sensors - as carried aboard the ERS and Envisat spacecraft - which function by measuring the precise time a radar pulse takes to bounce back to its satellite.

The French firm CLS (Collecte, Localisation Satellites), with support from French space agency CNES, processes altimetry data from the satellites ERS-2, Envisat, GFO, TOPEX/Poseidon and Jason-1 in the frame of a project called SSALTO/DUACS (Segment for ALTimetry, Orbitography and precise localisation/ Developing Use of Altimetry for Climate Studies). Mercator Ocean, the French contribution to GODAE, assimilates those data in its three-dimensional forecasting model of the global ocean, updated weekly.

Slight centimetre-scale height variations in sea height provide information on ocean currents and temperature – warm currents can stand around half a metre higher than colder surrounding waters – plus salinity, the current surface state, the underlying bathymetry of the seabed and even variations in the planet’s gravity field.

Additional, operational applications include marine routing, ensuring safety at sea, laying marine cables and optimising fishing fleet performance.

Altimetry also provides authoritative global measurements of sea level change – one of the most important ocean-related variables, because a large enough upward shift (due to polar melting or other factors) might erode human habitats and alter the very face of our planet. The evidence from space so far suggests a steady average rise of 0.3 millimetres a year.

Monitoring water quality

With around a third a third of EU territory covered by seas, the ocean is an important area of activity within Global Monitoring for Environment and Security (GMES) - a joint initiative of ESA and the European Union (EU) to integrate all available space- and ground-based information sources to yield accurate portraits of the current state of our planet.

ESA’s initial portfolio of Earth Observation-based services known as the GMES Services Element (GSE) includes a focus on water quality monitoring, with a focus on two important applications: the detection and tracking of oil spills – both chemically and physically hazardous to the marine environment - and forecasting toxic algae blooms, which threaten costly contamination of Europe’s growing aquaculture – fish or shellfish farming - industry.

Ocean colour satellite sensors such as Envisat’s Medium Resolution Imaging Spectrometer (MERIS) can reveal a lot about the contents of seawater: the ocean tint seen from space can be run through specialised algorithms to pinpoint its suspended contents, including marine phytoplankton, sediment loading and pollution.

Identifying oil spills

For detecting oil pollution, radar sensors such as Envisat’s Advanced Synthetic Aperture Radar (ASAR) are effective. Oil has a dampening affect on the water it floats on, returning less signal backscatter to show up blacker in a radar image.

Radar surveillance of accidental oil spills has shown its worth repeatedly, notably during the Prestige tanker accident off Spain’s Galician coast in November 2002. An Envisat image revealed the spill had split in two, providing a novel insight into the extent of coastline in danger.

However 90% of oil pollution at sea is not accidental but actually due to deliberate dumping. Systematic wide-area surveillance foreseen as part of GMES promises to help deter such illegal activity.

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

More articles from Ecology, The Environment and Conservation:

nachricht Upcycling 'fast fashion' to reduce waste and pollution
03.04.2017 | American Chemical Society

nachricht Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>