Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Tracking alien turbulences with Venus Express

05.04.2007
New images and data from ESA’s mission to Venus provide new insights into the turbulent and noxious atmosphere of Earth’s sister planet. What causes violent winds and turbulences? Is the surface topography playing a role in the complex global dynamics of the atmosphere? Venus Express is on the case.
Venus’ atmosphere represents a true puzzle for scientists. Winds are so powerful and fast that they circumnavigate the planet in only four Earth days – the atmospheric ‘super-rotation’ – while the planet itself is very slow in comparison, taking 243 Earth days to perform one full rotation around its axis.
At the poles things get really complicated with huge double-eyed vortices providing a truly dramatic view. In addition, a layer of dense clouds covers the whole planet as a thick curtain, preventing observers using conventional optical means from seeing what lies beneath.

Venus Express is on the contrary capable of looking through the atmosphere at different depths, by probing it at different infrared wavelengths. The Ultraviolet, Visible and Near-Infrared Mapping Spectrometer (VIRTIS) on board is continuing its systematic investigation of Venus’ atmospheric layers to solve the riddle of the causes for such turbulent and stormy atmosphere.
The images presented with this article focus on Venusian atmospheric turbulences and cloud features, whose shape and size vary with planetary latitudes. At the equator, clouds are irregular and assume a peculiar ‘bubble’-shape. At mid latitudes they are more regular and streaky, running almost parallel to the direction of the super rotation with speed reaching more than 400 kilometres per hour. Going higher up in latitude, in the polar region, the clouds end up in entering a vortex shape.

With its multi-wavelength eyes, VIRTIS can observe the atmosphere and the cloud layers not only at different depths, but also both in the day- and night-side of the planet – a characteristic that allows an overall assessment of the ‘environmental’ causes that can be at the origin of such an atmospheric complexity.
At the equator, the extremely violent winds of the super-rotation are in constant ‘battle’ with other kinds of local turbulences, or ‘regional’ winds, creating very complex cloud structures.

One type of regional wind is due to the strong flux of radiation from the Sun reaching the atmosphere of the planet on the day-side. This flux heats up the atmosphere creating convective cells, where masses of warm air move upwards and generate local turbulence and winds.
On the night-side there is obviously no flux from the Sun, but the clouds’ shape and the wind dynamics are somehow similar to that we see on the day-side. So, scientists are currently trying to understand if there is any mechanism other than ‘convection’ responsible for the equatorial turbulences, both on the day- and night-side of Venus.

For instance, VIRTIS imaged clouds over Alpha Regio, an area close to the equator. This area is characterised by a series of troughs, ridges, and faults that are oriented in many directions, with surface features that can be up to 4 kilometres high. There might be a connection between the surface topography and the local atmospheric turbulence which is observed in this area. This and other hypotheses are being investigated by the Venus Express science teams using data from several instruments.

Actually, the Venusian topography may play an important role also in the global atmospheric dynamics. Understanding this surface-atmosphere connection is one of the major objectives of Venus Express - something to be verified in the whole course of the mission.

Håkan Svedhem | EurekAlert!
Further information:
http://www.esa.int/SPECIALS/Venus_Express/SEM9N77DWZE_0.html

More articles from Physics and Astronomy:

nachricht Study offers new theoretical approach to describing non-equilibrium phase transitions
27.04.2017 | DOE/Argonne National Laboratory

nachricht SwRI-led team discovers lull in Mars' giant impact history
26.04.2017 | Southwest Research Institute

All articles from Physics and Astronomy >>>

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

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

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Bare bones: Making bones transparent

27.04.2017 | Life Sciences

Study offers new theoretical approach to describing non-equilibrium phase transitions

27.04.2017 | Physics and Astronomy

From volcano's slope, NASA instrument looks sky high and to the future

27.04.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>