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 Hundreds of bubble streams link biology, seismology off Washington's coast
22.03.2019 | University of Washington

nachricht Atmospheric scientists reveal the effect of sea-ice loss on Arctic warming
11.03.2019 | Institute of Atmospheric Physics, Chinese Academy of Sciences

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: The taming of the light screw

DESY and MPSD scientists create high-order harmonics from solids with controlled polarization states, taking advantage of both crystal symmetry and attosecond electronic dynamics. The newly demonstrated technique might find intriguing applications in petahertz electronics and for spectroscopic studies of novel quantum materials.

The nonlinear process of high-order harmonic generation (HHG) in gases is one of the cornerstones of attosecond science (an attosecond is a billionth of a...

Im Focus: Magnetic micro-boats

Nano- and microtechnology are promising candidates not only for medical applications such as drug delivery but also for the creation of little robots or flexible integrated sensors. Scientists from the Max Planck Institute for Polymer Research (MPI-P) have created magnetic microparticles, with a newly developed method, that could pave the way for building micro-motors or guiding drugs in the human body to a target, like a tumor. The preparation of such structures as well as their remote-control can be regulated using magnetic fields and therefore can find application in an array of domains.

The magnetic properties of a material control how this material responds to the presence of a magnetic field. Iron oxide is the main component of rust but also...

Im Focus: Self-healing coating made of corn starch makes small scratches disappear through heat

Due to the special arrangement of its molecules, a new coating made of corn starch is able to repair small scratches by itself through heat: The cross-linking via ring-shaped molecules makes the material mobile, so that it compensates for the scratches and these disappear again.

Superficial micro-scratches on the car body or on other high-gloss surfaces are harmless, but annoying. Especially in the luxury segment such surfaces are...

Im Focus: Stellar cartography

The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.

A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...

Im Focus: Heading towards a tsunami of light

Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.

"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Solving the efficiency of Gram-negative bacteria

22.03.2019 | Life Sciences

Bacteria bide their time when antibiotics attack

22.03.2019 | Life Sciences

Open source software helps researchers extract key insights from huge sensor datasets

22.03.2019 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>