Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Three ESA satellites reveal Etna’s complexity

31.10.2002


As detected by ESA satellite sensors, the recent eruptions of the Mount Etna volcano in Sicily are throwing huge amounts of ash and trace gases into the atmosphere. Working with data from the Global Ozone Monitoring Experiment (GOME) sensor onboard ESA’s ERS-2 spacecraft, scientists at the German aerospace centre (DLR) report that levels of sulphur dioxide from the eruptions on Sunday and Monday are at least 20 times higher than normal.


A plume of smoke and ash from Sicily’s Mount Etna is seen in this image acquired 28 October 2002 by the Medium Resolution Imaging Spectrometer (MERIS) instrument onboard ESA’s Envisat Satellite
Credits: ESA



As detected by ESA satellite sensors, the recent eruptions of the Mount Etna volcano in Sicily are throwing huge amounts of ash and trace gases into the atmosphere. Sensors onboard three different ESA spacecraft have acquired imagery of the eruptions that shed new light on the event and its impact on the Earth’s environment.
Working with data from the Global Ozone Monitoring Experiment (GOME) sensor onboard ESA’s ERS-2 spacecraft, scientists at the German aerospace centre (DLR) report that levels of sulphur dioxide from the eruptions on Sunday and Monday are at least 20 times higher than normal.

This latest activity from Mt. Etna, the second in a little over a year, marks the beginning of another period of activity of Europe’s largest volcano, says Werner Thomas, an atmospheric scientist with DLR’s Remote Sensing Technology Institute.



“As in July and August 2001 eruptions of Etna, dense ash clouds and gaseous emissions were again detected by several space-borne sensors,” he said.

The normal background level of sulphur dioxide is typically below 0.5 Dobson Units (DU), a measure of atmospheric gas concentrations from ground level to the top of the atmosphere, about 70 km in altitude.

"In the plume, we measured atmospheric content of sulphur dioxide of about 10 DU, at least 20 times higher than normal," Thomas said.

Sulphur dioxide in the troposphere, the lowest part of the atmosphere where most weather changes occur, is known to be responsible for the so-called "acid rain" phenomenon. Stratospheric sulphur dioxide, from about 11 km to 50 km above the Earth’s surface, causes the formation of sulphate aerosol particles that may have a serious impact on the global climate. Mt. Etna is one of the most prominent sources of natural sulphur dioxide worldwide.

The ERS’ GOME instrument is dedicated for remote sensing of the atmosphere and can detect a variety of atmospheric trace gases, including sulphur dioxide. The first GOME data after the beginning of the eruptions was recorded and analysed on 29 October around 10:15 UTC. As seen in the accompanying chart, enhanced levels of sulphur dioxide are evident in the southeast of Sicily, indicating that the tropospheric sulphur dioxide was carried away from the volcano by the winds in that direction.

The Italian government declared a state of emergency yesterday in Sicily in the wake a series of earthquakes, measuring between 3.6 and 4.3 on the Richter scale, that forced the evacuation of approximately 1 000 homes, according to reports from BBC and Italian newspapers. Meanwhile, three streams of lava from the eruption flowed down the south, northeast and northwest slopes of the mountains, media reports stated.

Europe’s highest and most active volcano (3370 m) hurled lava and ash from several craters into the sky with a speed between 350 and 450 metres per second, exceeding the speed of sound. According to data from volcanologists, the lava and ash were ejected from the main crater and from at least nine new craters that developed in the mountain between 2300 to 2700 metres in altitude.

As seen in the image acquired Monday by the Medium Resolution Imaging Spectrometer (MERIS) onboard ESA’s Envisat satellite, the eruptions spewed significant amounts of ash, along with sulphur dioxide, into the atmosphere The plume from the volcano can be seen in the image stretching south and west from Sicily to the north African coast. The larger volcanic ash particles are expected to settle out in a short period of time, but the sulphuric acid aerosols produced by the sulphur dioxide will persist for several years.

These aerosols will impact the Earth’s energy budget, both regionally and on a global scale. Aerosols containing black graphite and carbon particles are dark, thus absorbing sunlight. As these atmospheric particles reduce the amount of sunlight reaching the planet’s surface, they increase the amount of solar energy absorbed in the atmosphere, thus simultaneously cooling the surface and warming the atmosphere.

The capability of the MERIS instrument to observe the spatial distribution of these aerosol plumes can be exploited to measure the amounts of airborne particles and to examine the role of these aerosols as cloud condensation nuclei and their impact on the hydrologic cycle through changes in cloud cover, cloud properties and precipitation.

Today’s images from Proba

Just 60x60x80 cm and weighing only 94 kg, ESA’s Project for On-Board Autonomy satellite, better known as Proba, is one of the most advanced small satellites ever flown in space.

Since its launch last year, Proba’s high-performing computer system and technologically advanced instruments have enabled it to demonstrate and evaluate onboard operational autonomy, new spacecraft technology both hardware and software, and to test Earth observation and space environment instruments in space.

The imagery captured today by Proba demonstrate the capabilities of CHRIS, the Compact High Resolution Imaging Spectrometer, which is providing important information on the Earth and its environment, and will be a valuable tool in remote sensing during the extended mission.

The instrument acquired the accompanying Etna images in four standard bands, although the instrument is capable of image acquisition in up to 19 different bands.

Erica Rolfe | ESA

More articles from Earth Sciences:

nachricht Large-Mouthed Fish Was Top Predator After Mass Extinction
26.07.2017 | Universität Zürich

nachricht Strength of tectonic plates may explain shape of the Tibetan Plateau, study finds
25.07.2017 | University of Illinois at Urbana-Champaign

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Physicists Design Ultrafocused Pulses

Physicists working with researcher Oriol Romero-Isart devised a new simple scheme to theoretically generate arbitrarily short and focused electromagnetic fields. This new tool could be used for precise sensing and in microscopy.

Microwaves, heat radiation, light and X-radiation are examples for electromagnetic waves. Many applications require to focus the electromagnetic fields to...

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

 
Latest News

Programming cells with computer-like logic

27.07.2017 | Life Sciences

Identified the component that allows a lethal bacteria to spread resistance to antibiotics

27.07.2017 | Life Sciences

Malaria Already Endemic in the Mediterranean by the Roman Period

27.07.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>