Japanese Spacecraft Spots Massive Gravity Wave In Venus' Atmosphere (theverge.com)

← Back to Stories (view on slashdot.org)

Japanese Spacecraft Spots Massive Gravity Wave In Venus' Atmosphere (theverge.com)

Posted by BeauHD on Monday January 16, 2017 @07:00PM from the surf's-up dept.

An anonymous reader quotes a report from The Verge: The Japanese probe Akatsuki has observed a massive gravity wave in the atmosphere of Venus. This is not the first time such a wave was observed on the Solar System's second planet, but it is the largest ever recorded, stretching just over 6,000 miles from end to end. Its features also suggest that the dynamics of Venus' atmosphere are more complex than previously thought. An atmospheric gravity wave is a ripple in the density of a planet's atmosphere, according to the European Space Agency. Akatsuki spotted this particular gravity wave, described in a paper published today in Nature Geoscience, when the probe arrived at the planet on December 7th, 2015. The spacecraft then lost sight of it on December 12th, 2015, because of a change in Akatsuki's orbit. When the probe returned to a position to observe the bow-shaped structure on January 15th, 2016, the bright wave had vanished. What sets the huge December wave apart from previously discovered ones is that it appeared to be stationary above a mountainous region on the planet's surface, despite the background atmospheric winds. The study's authors believe that the bright structure is the result of a gravity wave that was formed in the lower atmosphere as it flowed over the planet's mountainous terrain. It's not clear how the wave exactly propagates to the planet's upper atmosphere, where clouds rotate faster than the planets itself -- four days instead of the 243 days it takes Venus to rotate once.

84 comments

Min score:

Reason:

Sort:

Note: Gravity wave != Gravitational wave by xyrw · 2017-01-16 19:19 · Score: 5, Informative

It's worth pointing out that the article talks about a gravity wave, which is a material wave that arises out of a disturbance due to gravity. This should not be confused with gravitational waves, which are ripples in spacetime due to the movement of masses. (The article and summary aren't wrong, but the terminology itself is confusing.)
The effect observed on Venus is in fact quite massive, while gravitational waves are tiny and difficult to observe.
1. Re:Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-16 20:05 · Score: 1
  
  Also, gravity wave != wind, it seems.
  But can someone explain the difference? Reading the wikipedia article on "gravity wave", it still sounds like a wind to me.
2. Re:Note: Gravity wave != Gravitational wave by ASDFnz · 2017-01-16 20:24 · Score: 3, Informative
  
  It is a bit of a picky difference since a gravity wave can be caused by wind.
  It is essentially the same thing as a wave on the sea which is also caused by wind (primarily) but can be caused by other things, for example, an explosion could cause waves in the sea and it could also cause a wave like this in an atmosphere.
  It is the difference between cause and effect.
  The odd thing about these waves (they have been seen before) no wind process (or any other process) that we are familiar with can cause a wave of this magnitude yet here they are.
3. Re: Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-16 20:55 · Score: 1
  
  It's misleading to say that gravity waves are caused by gravity. Yes, gravity is required for gravity waves, but it's more complex. Gravity waves are named as such because gravity is the force that restores a vertically displaced parcel of air in a statically stable atmosphere to its original position. In reality, the parcel will overshoot its original location and will oscillate, creating a wave.
  If I force a parcel of air upwards, it will expand and cool, though the total energy of the parcel is conserved. If the atmosphere is stable, the parcel that has been forced upward will be cooler than its surroundings, and will experience a downward acceleration. Eventually the parcel will descend and acquire enough momentum to overshoot its original location. This occurs as a result of gravity, which causes the denser parcel to descend. When the parcel descends, it heats adiabatically, and will experience an upward acceleration after overshooting its original position. Thus the process repeats, and the parcel oscillates about its original position. Gravity is the restoring force, which is why it's called a gravity wave. If the atmosphere is unstable, the parcel will accelerate away from its original position, and a gravity wave will not occur.
  There is nothing remarkable about the presence of gravity waves on Venus, especially in the lower atmosphere. Gravity waves are very common in the Earth's atmosphere, too. In the presence of terrain, or anything else to vertically displace parcels of air in a statically stable atmosphere, there should be gravity waves. As I understand it, what's remarkable is the massive size of the gravity wave, the wave being stationary amidst the strong upper-level winds, and the vertical propagation of the wave into the upper atmosphere of Venus.
4. Re:Note: Gravity wave != Gravitational wave by silentcoder · 2017-01-16 21:04 · Score: 3, Informative
  
  Your conspiracy theory is flawed on a number of points.
  - The terms come from different sciences. Gravitational waves is from relativistic physics (and were first predicted by Einstein over a century ago). Gravity waves come from fluid dynamics and has an entirely different history.
  - Their sources differ. Gravity waves were observed, then named in the theories that explained them. Gravitational waves were predicted by a theory but not observed for another 110 years despite constant attempts along the way.
  
  --
  Unicode killed the ASCII-art *
5. Re:Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-16 21:04 · Score: 0
  
  THis is why I still come to slashdot.
  Wish I still had an account. THanks xyrw!
6. Re:Note: Gravity wave != Gravitational wave by nadaou · 2017-01-16 21:05 · Score: 4, Informative
  
  The odd thing about these waves (they have been seen before) no wind process (or any other process) that we are familiar with can cause a wave of this magnitude yet here they are.
  The basic phenomena is equivalent to a hydraulic in a river downstream of a rock. Kayakers have lots of fun playing in them. If the vertical density gradient in the atmosphere is small enough the waves can grow quite large without too much trouble. With a softly defined upper Venetian atmosphere I'd view it more as an internal wave than a surface wave, then it isn't too surprising.
  I am surprised at the apparent lack of Coriolis and no sign of something similar to Hadley cells at latitudes less than 60 degrees, but then again IANAPAP.
  
  --
  ~.~
  I'm a peripheral visionary.
7. Re: Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-16 21:13 · Score: 0
  
  Venus takes 243 days to rotate so coriolis effects would be much less
8. Re: Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-16 21:29 · Score: 1
  
  As I understand it, Venus has Hadley cells. Owing to the approximately spherical nature of the planet, there is a difference in the isolation between the equator and poles. This should create a temperature gradient, which then requires a poleward transport of heat. It lacks the three cells that are characteristic of Earth's general circulation due to the very weak Coriolis acceleration.
9. Re: Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-16 21:42 · Score: 0
  
  Actually, the name comes from the restoring force. In the case of gravity waves, gravity is the force that restores a displaced parcel back to its original location. There are other types of waves such as inertial waves, for which the restoring force is the Coriolis acceleration.
10. Re:Note: Gravity wave != Gravitational wave by Hognoxious · 2017-01-16 22:06 · Score: 2
  
  upper Venetian atmosphere
  
  Is it full of gondolas and red pigment?
  
  --
  Confucius say, "Find worm in apple - bad. Find half a worm - worse."
11. Re:Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-16 22:44 · Score: 0
  
  Indeed, the effect of gravitational waves is tiny, but the energy/area at earth of the recent LIGO observation(s) are really rather large. :)
12. Re: Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-16 23:35 · Score: 0
  
  Diseased sexual parts, too
13. Re:Note: Gravity wave != Gravitational wave by Warma · 2017-01-17 00:44 · Score: 2
  
  But they are. It's called a gravity wave because the force of gravity is supplying the force trying to restore equilibrium.
14. Re:Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-17 00:54 · Score: 0
  
  Do you know the difference in the ocean between a current and a wave? Same thing.
15. Re: Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-17 01:06 · Score: 0
  
  I think you can use Legos to detect gravity waves.
16. Re: Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-17 01:35 · Score: 5, Informative
  
  I'm the same AC who tried to explain the concept of gravity waves. Parcel theory is a common assumption in meteorology (see http://www.srh.noaa.gov/jetstream/upperair/parcels.html as one of a huge number of examples), even though its conditions are usually violated to some degree in the real atmosphere. Sure, parcel theory isn't perfect, but it does a pretty good job of explaining a lot of things in the atmosphere. It's also extremely common to use it in meteorology to determine things like the amount of instability in the atmosphere or to estimate vertical motions resulting from isentropic upglide and downglide. Anyone who has ever looked at a skew-t diagram from computer model forecast (extremely common in thunderstorm and severe weather forecasting) is applying parcel theory. There area a lot of things we do in meteorology that simplify how the atmosphere works to make forecasting easier. Parcel theory is one of those things, and yet it does a pretty damn good job when we apply it to the real atmosphere.
  Yes, the conditions of parcel theory are violated in the real atmosphere. Yes, mixing is one of the ways parcel theory is violated. However, it still works quite well and is extremely common in forecasting. So, although you're technically correct that parcel theory is violated in the real atmosphere, it's usually a close approximation. Entrainment usually isn't significant enough to make a big difference most of the time. That's because usually large volumes of air are displaced, and entrainment generally only occurs around the edges. For example, in a growing cloud, there's entrainment of dry air at the edges, but the interior of the cloud is unlikely to experience much impact from entrainment. The cloud is large enough that the entering is mostly insulated from the effects of entrainment.
  As for your cows comment, fuck you.
17. Re: Note: Gravity wave != Gravitational wave by drinkypoo · 2017-01-17 01:48 · Score: 0
  
  As for your cows comment, fuck you.
  Thanks for making my day.
  
  --
  "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
18. Re:Note: Gravity wave != Gravitational wave by Maritz · 2017-01-17 02:01 · Score: 3, Insightful
  
  By calling it a gravity wave, you just look stupid and ignorant of the topic of discussion.
  From here:
  
  "By studying how the atmospheric densities changed and were perturbed over time, we found two different types of wave: Atmospheric gravity waves and planetary waves," explained co-author Sean Bruinsma of the Centre National D'Etudes Spatiales (CNES), France."
  I'm sure he'll be heartbroken that BitZtream from Slashdot thinks he stupid. But then, armchair blowhard slashdot experts truly do know everything, so how can he compete?
  
  --
  I do not want your cheap brainburning drugs. They are useless for work. And I am a working man today.
19. Re: Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-17 02:06 · Score: 2, Interesting
  
  Gravity waves depend on the stability of the fluid (in this case, the atmosphere). If the fluid is unstable, the displaced air will accelerate away from its original location. It's the difference between a wave (stable) and a parcel (unstable). In meteorology, we usually discuss stability in terms of parcels because, although imperfect, the assumptions of parcel theory are close enough to be useful in explaining a lot of processes in the atmosphere.
  For those who are genuinely interested, here are a couple of links that explain gravity waves:
  http://www.theweatherprediction.com/habyhints/64/
  http://www.physics.uwo.ca/~whocking/p103/grav_wav.html
  Both links, of course, use parcels to help explain gravity waves. The second link is more detailed and introduces the related concept of the Brunt-Vaisala frequency (the period of a gravity wave oscillation; it is infinite or NaN for neutral stability and not purely real for unstable conditions), which is useful in meteorology.
  Would you like to contribute to the discussion, or are you just here to troll me, as your most recent post implies?
20. Re: Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-17 02:15 · Score: 4, Informative
  
  A gravity wave is not a compression wave. It is either called a gravity wave or, occasionally, a buoyancy wave. Such waves arise from the vertical displacement of a fluid in stable conditions. Gravity is the restoring force, causing the displaced fluid to return to and overshoot its original location, causing the wave. That's why it's called a gravity wave, a term that is extremely common in meteorology. Your post is factually incorrect.
21. Re: Note: Gravity wave != Gravitational wave by drinkypoo · 2017-01-17 02:33 · Score: 1, Troll
  
  In meteorology, we usually discuss stability in terms of parcels because, although imperfect, the assumptions of parcel theory are close enough to be useful in explaining a lot of processes in the atmosphere.
  I suppose my problem with it is the name. A parcel is a package. It's wrapped up in a container, by definition, even if that container is just paper. Why are scientists forever picking the most shit name for something? I guess this is a corollary to the saying about never letting software developers name anything. It seems that nerds in general should have their naming powers revoked.
  
  Would you like to contribute to the discussion, or are you just here to troll me, as your most recent post implies?
  I was actually just being snarky and making a funny, but once you started to rant, it did make me happy that you weren't enjoying it.
  
  --
  "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
22. Re:Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-17 02:47 · Score: 1
  
  It's like you think every time a scientist needs to name something he convenes the global Science Naming Convention with all scientists in all fields as members and in attendance. And there, they have a careful voting process to choose the best term.
  Instead of what really happens: some post doc who barely has enough time to read all of the papers in his own super narrow sub-sub-field hurriedly chooses a name he thinks is descriptive and sounds cool.
  And no one needs to disprove your conspiracy theory. The proof onus is on whoever's making the conspiracy theory claims. Until they've pulled some seriously hard evidence to back it up, us sane people can go on safely dismissing without evidence what has been stated without evidence and leave the proving and disproving of conspiracy theories to the crazies and the crackpots.
23. Re:Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-17 03:24 · Score: 0
  
  Or you could look into it before looking like and idiot considering the term gravity wave dates back to at least the 1840s with Airy's and Stoke's theoretical work on water waves.
24. Re: Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-17 03:32 · Score: 0
  
  Gravity waves don't involve much net vertical movement of air. The restoring force is gravity, and involves air just oscillating up and down in a particular layer, much like gravity waves in water. The rippling of a particular layer causes higher layers to ripple, and the effects can extend very high in the atmosphere until nonlinearities stop it. The effects can involve vertical transport of momentum and energy over an order of magnitude further in altitude than the actual distance a particular parcel of air oscillates.
25. Re: Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-17 03:38 · Score: 0
  
  Overshoot of air masses is something that a person can see for themselves by just looking for a dome on top of a large thunderstorm anvil. Such effects occur in both up and down directions. The whole reason we have things like weather fronts is because different temperature air masses don't simply just convect, mix, and smooth out any gradients.
26. Re: Note: Gravity wave != Gravitational wave by dpidcoe · 2017-01-17 04:48 · Score: 1
  
  I was actually just being snarky and making a funny, but once you started to rant, it did make me happy that you weren't enjoying it.
  Eh? The guy was sharing some good information that's highly relevant to the discussion on a subject he's clearly knowledgeable about. I find it kind of sad that on a site supposedly for nerds, you confuse an infodump for a rant.
27. Re:Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-17 05:00 · Score: 0
  
  PAP?
28. Re:Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-17 05:06 · Score: 1
  
  Its worth pointing out that its not a 'gravity way' at all.
  No, it is not worth pointing that out, since it is wrong.
  
  Its a simple compression wave. Gravity has exactly 0 to do with it.
  Wrong.
  
  By calling it a gravity wave, you just look stupid and ignorant of the topic of discussion.
  Wrong. Because it is a gravity way.
  It is not a gravitational wave. But nobody has said so, either.
  
  Thats typical for slashdot submissions and editors, but generally the comments have higher standards.
  Yes, except for yours, of course. Your comments tend to have lower standards, by quite some margin.
  Now, take your arrogance and fuck off. Please.
29. Re: Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-17 05:21 · Score: 0
  
  Planetary astrophysicist
30. Re: Note: Gravity wave != Gravitational wave by drinkypoo · 2017-01-17 05:23 · Score: 1
  
  I find it kind of sad that on a site supposedly for nerds, you confuse an infodump for a rant.
  No, I appreciated the informative part. But that wasn't the whole nature of the comment, either.
  
  --
  "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
31. Re:Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-17 05:40 · Score: 0
  
  Just insinuate something about really good cheese pizza, and you're set.
32. Re:Note: Gravity wave != Gravitational wave by poofmeisterp · 2017-01-17 05:46 · Score: 2
  
  Also, gravity wave != wind, it seems.
  But can someone explain the difference? Reading the wikipedia article on "gravity wave", it still sounds like a wind to me.
  Wind is driven by pressure delta. I have no idea why they focus on gravity wave unless it involves a massive amount of material in the atmosphere of the mentioned medium area, that gravity has such a powerful visible effect on due to its density, that we have to play with words because the density is so high we have to give it a new term to paint a picture in someone's head of the magnitude of the effect. Sort of like "fucking awesome" -vs- "pretty cool"....? *shrug*
33. Re: Note: Gravity wave != Gravitational wave by poofmeisterp · 2017-01-17 05:47 · Score: 1
  
  I was actually just being snarky and making a funny, but once you started to rant, it did make me happy that you weren't enjoying it.
  Eh? The guy was sharing some good information that's highly relevant to the discussion on a subject he's clearly knowledgeable about. I find it kind of sad that on a site supposedly for nerds, you confuse an infodump for a rant.
  Now everyone is an "Aspie".
34. Re:Note: Gravity wave != Gravitational wave by wonkey_monkey · 2017-01-17 05:54 · Score: 2
  
  Its worth pointing out that its not a 'gravity way' at all. Its a simple compression wave. Gravity has exactly 0 to do with it.
  Gravity has plenty to do with it. Perhaps you should have at least checked the Wikipedia page on the subject before making an arse out of yourself. Again.
  
  --
  systemd is Roko's Basilisk.
35. Re:Note: Gravity wave != Gravitational wave by nadaou · 2017-01-17 06:40 · Score: 3, Funny
  
  Two possible explanations here:
  1) auto-correct typo.
  2) a subtle reference to Giovanni Schiaparelli's Martian canali.
  You'll never know.
  
  --
  ~.~
  I'm a peripheral visionary.
36. Re: Note: Gravity wave != Gravitational wave by nadaou · 2017-01-17 06:50 · Score: 1
  
  Close, planetary atmospheric physicist
  
  --
  ~.~
  I'm a peripheral visionary.
37. Re:Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-17 07:34 · Score: 0
  
  For future reference: venusian, veneric, venerean, venerian, venereal, ... Cf mercurial, martial, jovial, saturnine
38. Re:Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-17 09:31 · Score: 0
  
  Its worth pointing out that its not a 'gravity way' at all. Its a simple compression wave. Gravity has exactly 0 to do with it.
  By calling it a gravity wave, you just look stupid and ignorant of the topic of discussion.
  Thats typical for slashdot submissions and editors, but generally the comments have higher standards.
  It's worth pointing out that Bitztream is an incestuous fuckwit that just pwned himself by yet again posting is idiotic dribblings! A-HA!
39. Re: Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-17 10:09 · Score: 0
  
  Go die in a Martian canale, you Schiaparelli faggot.
40. Re:Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-17 14:09 · Score: 0
  
  Its worth....
  " It's "
41. Re:Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-17 16:04 · Score: 0
  
  Thats typical for ...
  " That's "
42. Re:Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-18 03:15 · Score: 1
  
  you just look stupid and ignorant of the topic of discussion.
  Says the idiot that doesn't know how presidential pardons work.
43. Re: Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-18 04:33 · Score: 0
  
  Ahh, so you had to spell it out anyway, so why didn't you just fucking do it in the first place?
44. Re: Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-18 07:36 · Score: 0
  
  Don't pay any attention to drinky. This is his only "social" interaction, so he can't play well with others.
45. Re:Note: Gravity wave != Gravitational wave by Anonymous Coward · 2017-01-18 07:36 · Score: 0
  
  So, then, it's a density wave.
46. Re: Note: Gravity wave != Gravitational wave by RockDoctor · 2017-01-20 08:13 · Score: 1
  
  What? Only if it's in a balloon. Otherwise it will mix with other air through convection, and it won't be a parcel of air any more.
  Actually, it's a sufficiently good approximation to use. And you can see it for yourself any day when there are cumulus clouds in the sky - the border in the sky that you can see between the cooler cloud (where the water vapour has condensed out to make tiny droplets - which we see as the "white" of the cloud) and the (close to) transparent air-with-water-vapour, is the border of a "parcel" of air that has risen, as a parcel, after being heated over a source such as a forest, or bright field of flowering oilseed rape.
  If you'd flown a glider, or been attentive when landing a conventional plane in turbulence, you'd have felt the impact of those different "parcels" of air. Yes, they can rip lumps off aircraft.
  
  Go back to your spherical cows and let us be.
  Stop being a fuckwit. You can be better than that. The AC provided good information about a complex phenomenon which most people don't understand at all well.
  
  --
  Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
Not to be confused with... by Anonymous Coward · 2017-01-16 19:20 · Score: 0

A gravitational wave; which, makes this substantially less interesting.
Note that what's large... by Rei · 2017-01-16 20:01 · Score: 3, Informative

.... is the size, not the intensity. The air moves only slightly faster or slower than the surrounding atmosphere as one passes through the wave.
They weren't expected on Venus, though. Venus's surface is dozens of kilometers down, thick and "soupy" there, transitioning to thinner layers above. It was surprising to see that surface features that far away, in a fluid that can compress, would still make clear phenomena like gravity waves in the high atmosphere.

--
Dear Diary...today I was pompous and my sister was crazy.
1. Re: Note that what's large... by Anonymous Coward · 2017-01-16 21:12 · Score: 1
  
  I'm not very familiar with the structure of the Venusian atmosphere, so maybe there's something I don't understand here. In the Earth's atmosphere, the tropopause acts a bit like a flexible lid. For example, if you have a thunderstorm that ascends to the tropopause, you will get an overshooting top as the updraft parcels are carried past their equilibrium level by the momentum they andcquired in the updraft. They will then oscillate as gravity waves along the thunderstorm anvil, which has been observed in satellite images. The equilibrium level is generally pretty close to the tropopause and it behaves as a lid, but one that's not rigid. That is, its high static stability dampens waves quickly, but is not completely rigid. Winds flowing over a mountain range will create gravity waves, but will also propagate upward to some degree, especially in conditions that are less statically stable. For example, winds flowing over the Rocky Mountains in Colorado create gravity waves that propagate downstream but also upward. You can actually feel the effects of those waves in the lower stratosphere, if you encounter turbulence as you fly over the Front Range. Even though the stratosphere is very statically stable, it flexes upward while dampening the upward propagation of the waves. As I understand it, Venus does not have a stratosphere. On Earth, a significant part of the vertical dampening is due to the stratosphere, but it seems that Venus lacks such a statically stable layer. Is it simply the extreme viscosity that should limit the upward propagation of the waves, then?
2. Re: Note that what's large... by Rei · 2017-01-17 00:34 · Score: 4, Informative
  
  Venus has multiple "tropopauses" and "stratospheres", depending on how you define them. The atmosphere is like a layer cake with multiple convection zones (like Earth's troposphere) separated by areas of dynamic stability (like Earth's stratosphere). And again, ~50-70km is an awfullly long way from the surface, and surface winds are weak. But, there's a lot about Venus that we don't understand.
  
  --
  Dear Diary...today I was pompous and my sister was crazy.
3. Re: Note that what's large... by Anonymous Coward · 2017-01-17 05:08 · Score: 0
  
  Overshoot and the boundary and the tropopause are not directly related to gravity waves. Gravity waves will form in air layers that are already at the correct height for their buoyancy, such that any perturbation has gravity restoring it back to where it was before. That gives you a simple oscillator, so it will ring up and down simply from trying to get back to the correct altitude, without any need for say cooling from expansion that is more relevant to an overshooting of a thunderstorm. Gravity waves expand to other layers of air by simply disturbing the layers above them, and since the temperature gradient isn't needed in a certain direction, the gravity wave can expand pass the tropopause without much difficulty.
  That said, temperature and velocity gradients can contribute to nonlinear effects. If the waves were completely linear, the gravity wave would cover the entire vertical extent of the atmosphere. Even with nonlinear dampening, the effects can extend into the mesosphere.
4. Re:Note that what's large... by cwsumner · 2017-01-18 07:52 · Score: 1
  
  It sounds like a "standing wave" in the winds over the mountains. Which could maintain pressure differences that extend much higher and remain for a time.
  Such waves can even have their own internal circulation, such as a horizontal rolling wind that is like a "tube" downwind from the mountains. I have seen such things near where I live, and I have seen videos available online.
  But when the wind at lower levels changes, the standing wave could dissipate quite quickly.
  Have such waves been seen in earth's upper atmosphere levels, from the ISS?
Re:Stop already by Anonymous Coward · 2017-01-16 20:43 · Score: 0

I can correct people on the difference between gravitational waves and gravity waves and
jack off in my mom's basement at the same time, thank you very much!
Re:Stop already by Anonymous Coward · 2017-01-16 20:46 · Score: 0

retard
Move along, nothing to see by r1348 · 2017-01-16 20:57 · Score: 2, Funny

Just the protomolecule building the Ring...
1. Re:Move along, nothing to see by TheDarkMaster · 2017-01-16 22:28 · Score: 1
  
  Uh oh...
  
  --
  Religion: The greatest weapon of mass destruction of all time
new lens sees rt wave by Anonymous Coward · 2017-01-16 21:27 · Score: 0

of the sun but its venus and mars shine
No mention on NHK in Japan? by shanen · 2017-01-17 00:12 · Score: 1

Just watching another news program and sort of disappointed it didn't get any coverage. The last few days had quite a bit of coverage about a new and quite small orbit-capable rocket, though the payload is quite small, on the order of 3 kg. There were several stories before the launch, and then some reports of the failure. (The early reports suggest a telemetry failure?)

--
Freedom = (Meaningful - Coerced) Choice != (Speech | Beer^2), and sad sock puppets' bad mods avail them naught.
Why always miles?! by Tomahawk · 2017-01-17 00:32 · Score: 1

"Here we report the detection of an interhemispheric bow-shaped structure stretching 10,000km across at the cloud-top level of Venus..."
from the original article, for those of us that don't know archaic measurements.
1. Re:Why always miles?! by Anonymous Coward · 2017-01-17 01:47 · Score: 0
  
  "Here we report the detection of an interhemispheric bow-shaped structure stretching 10,000km across at the cloud-top level of Venus..."
  from the original article, for those of us that don't know archaic measurements.
  Because you're clearly smart enough to do conversions yourself.
2. Re:Why always miles?! by Anonymous Coward · 2017-01-17 01:57 · Score: 0
  
  And because people in the three remaining non-metric countries (Liberia, United States, Myanmar) are not.
I spotted a wave by Anonymous Coward · 2017-01-17 01:41 · Score: 0

I spotted a wave near Uranus. It stinks!!!!
1. Re:I spotted a wave by dcw3 · 2017-01-18 07:42 · Score: 1
  
  I spotted a wave near Uranus. It stinks!!!!
  Please remove your proboscis from the sphincter to correct your problem.
  
  --
  Just another day in Paradise
Mexican Gravity wave on Venus... by Oswald+McWeany · 2017-01-17 02:12 · Score: 1

Next it passes to Earth... then Mars... until it goes all around the solar system and returns back to Mercury.

--
"That's the way to do it" - Punch
1. Re:Mexican Gravity wave on Venus... by RockDoctor · 2017-01-20 08:19 · Score: 1
  
  To pass "around" the Solar system, you'd need to get at least the Kuiper belt involved.
  
  --
  Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
It's bitztream... by Anonymous Coward · 2017-01-17 02:22 · Score: 1

the autism-hating, custom EpiPen-hating, Musk-hating Slashdot troll that can't stand Slashdot or its stories or its editors or commenters so always insults everybody.
1. Re: It's bitztream... by Anonymous Coward · 2017-01-17 04:04 · Score: 0
  
  It's Butters!!!
  That's meeeeee!!!
That's just a belter conspiracy theory by thesandbender · 2017-01-17 02:34 · Score: 1

You've been listening to that Holden guy too much :-)
So, by BitztreamNotARealNam · 2017-01-17 16:01 · Score: 2

How's life in the hypocrite lane?
(Not too well today I see...)