Featured Research

from universities, journals, and other organizations

Venus vortices go for chaotic multi-storey strolls around the poles

Date:
March 24, 2013
Source:
Europlanet Media Centre
Summary:
A detailed study of Venus' South Polar Vortex shows a much more chaotic and unpredictable cyclone than previously thought. The analysis reveals that the center of rotation of the vortex wanders around the pole differently at different altitude levels in the clouds of Venus. In its stroll around the Pole, in layers separated by 20 km, the vortex experiences unpredictable changes in its morphology.

The South Polar Vortex of Venus changes its shape day-to-day. The upper panels of the figure show the upper clouds at 63km above the surface and the lower panels present the vortex as observed in the lower clouds at 42km altitude level.
Credit: ESA/VIRTIS/INAF-IASF/Obs. de Paris-LESIA/Universidad del Paνs Vasco (I. Garate-Lopez)

A detailed study of Venus' South Polar Vortex shows a much more chaotic and unpredictable cyclone than previously thought. The analysis reveals that the center of rotation of the vortex wanders around the pole differently at different altitude levels in the clouds of Venus. In its stroll around the Pole, in layers separated by 20 km, the vortex experiences unpredictable changes in its morphology.

The results of this study are published online in Nature Geoscience today.

The study, entitled 'A chaotic long-lived vortex at the southern pole of Venus', used infrared images from VIRTIS instrument onboard the European Space Agency's Venus Express spacecraft. VIRTIS provides spectral images at different levels of the atmosphere and allows the observation of the lower and upper clouds of Venus.

Atmospheric vortices are common in the atmospheres of different planets of the Solar System, although they have different behaviors. Venus is a planet similar to Earth in size, but very different in other aspects. It rotates slowly around its axis, with a day on Venus lasting 243 Earth-days, and it spins in the opposite direction to Earth. Its dense carbon dioxide atmosphere, with surface pressures of 90 times that of Earth, causes a runaway greenhouse effect that raises the surface temperatures up to 450ΊC. Between 45 and 70km above the surface there is a dense layer of sulfuric acid clouds that completely covers the planet and moves at speeds of 360km/h in a phenomenon named superrotation, where the atmosphere rotates much faster than the surface of the planet. The origin of this effect is still unknown.

At the poles of Venus, the atmospheric circulation forms intense and permanent vortices that change shape and size on a daily basis. In the new analysis published today, researchers report that the winds in the vortex, which were tracked by studying images obtained by the Venus Express orbiter, change chaotically from day-to-day. This unpredictable nature of the Venus polar vortices make them different from polar vortices found on other planets, like Earth or Saturn, which are much more stable and predictable.

The large-scale cyclone extends vertically in Venus' atmosphere over more than 20 kilometers, through a region of highly turbulent, permanent clouds. However, the centers of rotation at two different altitude levels (42 and 62 km above the surface) are not aligned and both wander around the south pole of the planet with no established pattern at velocities of up to 55km/h. The study also finds that even when averaged cross-winds are roughly the same at both altitudes, there is still a strong vertical gradient, with winds increasing by as much as 3km/h for every kilometer of height and leading to possible atmospheric instabilities.

The vortices are fed by the atmospheric superrotation and are trapped in polar regions by a wide, shallow collar of cold air in subpolar latitudes. The eye at the centre of the vortex covers an average area of 2200 kilometres by 1400 kilometres. Despite several years of observations, it is not possible to explain why the vortex is variable enough to alter its shape in just one day, or remain stable for weeks. Thus, along with the origin of the superrotation of the atmosphere, identification of a mysterious source of ultraviolet absorption in the clouds, Venus polar vortices are one of the great mysteries of our twin planet. This study will help for a more precise explanation of the vortex and its relationship with the atmospheric superrotation.


Story Source:

The above story is based on materials provided by Europlanet Media Centre. Note: Materials may be edited for content and length.


Journal Reference:

  1. I. Garate-Lopez, R. Hueso, A. Sαnchez-Lavega, J. Peralta, G. Piccioni, P. Drossart. A chaotic long-lived vortex at the southern pole of Venus. Nature Geoscience, 2013; DOI: 10.1038/NGEO1764

Cite This Page:

Europlanet Media Centre. "Venus vortices go for chaotic multi-storey strolls around the poles." ScienceDaily. ScienceDaily, 24 March 2013. <www.sciencedaily.com/releases/2013/03/130324152140.htm>.
Europlanet Media Centre. (2013, March 24). Venus vortices go for chaotic multi-storey strolls around the poles. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2013/03/130324152140.htm
Europlanet Media Centre. "Venus vortices go for chaotic multi-storey strolls around the poles." ScienceDaily. www.sciencedaily.com/releases/2013/03/130324152140.htm (accessed July 25, 2014).

Share This




More Space & Time News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Space to Ground: Coming and Going

Space to Ground: Coming and Going

NASA (July 25, 2014) — One station cargo ship leaves, another arrives, aquatic research and commercial spinoffs. Questions or comments? Use #spacetoground to talk to us. Video provided by NASA
Powered by NewsLook.com
Raw: ISS Cargo Ship Launches in Kazakhstan

Raw: ISS Cargo Ship Launches in Kazakhstan

AP (July 23, 2014) — The Progress 56 cargo ship launched from the Baikonur Cosmodrome in Kazakhstan Wednesday. NASA says it will deliver cargo and crew supplies to the International Space Station. (July 23) Video provided by AP
Powered by NewsLook.com
Raw: Cargo Craft Undocks from Space Station

Raw: Cargo Craft Undocks from Space Station

AP (July 22, 2014) — A Russian Soyuz cargo-carrying spacecraft undocked from the International Space Station on Monday. The craft is due to undergo about ten days of engineering tests before it burns up in the Earth's atmosphere. (July 22) Video provided by AP
Powered by NewsLook.com
NASA Ceremony Honors Moon Walker Neil Armstrong

NASA Ceremony Honors Moon Walker Neil Armstrong

AP (July 21, 2014) — NASA honored one of its most famous astronauts Monday by renaming a historic building at the Kennedy Space Center in Florida. It now bears the name of Neil Armstrong, the first man to walk on the moon. (July 21) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

    Health News

      Environment News

        Technology News



          Save/Print:
          Share:  

          Free Subscriptions


          Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

          Get Social & Mobile


          Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

          Have Feedback?


          Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
          Mobile iPhone Android Web
          Follow Facebook Twitter Google+
          Subscribe RSS Feeds Email Newsletters
          Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins