Huge Storms Converge on Jupiter

tpoker writes to tell us NASA is reporting that the two biggest storms in the solar system are about to collide on Jupiter. From the article: "Storm #1 is the Great Red Spot, twice as wide as Earth itself, with winds blowing 350 mph. The behemoth has been spinning around Jupiter for hundreds of years. Storm #2 is Oval BA, also known as 'Red Jr.,' a youngster of a storm only six years old. Compared to the Great Red Spot, Red Jr. is half-sized, able to swallow Earth merely once, but it blows just as hard as its older cousin."

Comments

Re:Nice job, editors!

[raehl]

The summary is spot on! (Ba-dum, chink!)

Except for the whole basic math thing.

If one object is two earths wide, and another object is one earth wide, the 2nd object is one FOURTH the size of the first, not one half.*

* Assumes objects are of the same shape and the shape is uniform in one dimension. Which should be pretty good assumptions in this case.

Collide?

[thePig]

From the article "There won't be a head-on collision. and the storms' outer bands will pass quite close to one another.
I guess the summary was a little bit of a hyperbole. Esp. for an event that happens every two years.

Re:Collide?

[jbrader]

You're right, but they're expected to come closer this time then they have in the past.

Re:Collide?

[helioquake]

No, they aren't closer. It's the same as the last two encounter.

What signifies about this particular encounter is that the small oval is thought to be intensified its strength recently (when its color changed from grey to red) and that just *might* cause a bit more interesting interaction between these two storms (when they pass by closely). It's a pure speculation based none other than intuition of scientists. Not based on a hydrodynamic simulation; just a wild ass guess on their part.

Of course, they wouldn't say that. That'd make this whole thing, well, boring.

Re:Collide?

[ObsessiveMathsFreak]

Not based on a hydrodynamic simulation; just a wild ass guess on their part.

Fluid dynamics, particularly on such a massive scale as storms on a planet like Jupiter, is still largely a matter of wild ass "guess"timates. With good reason.

The basic equations of fluid mechanics, the Navier-Stokes equations, are a second order, non-linear system of partial differential equations. Atmospheric gases are also compressible flows. Couple this with aerosols, rotation of the planet, and mondo awkward boundary conditions due to the surface curvature; it's lack of a crust; and the lack of a defined "end" of the atmosphere, finally sprinkling a generous dose of chaos theory in to account for sensitivity to initial conditions.... and you've got a problem that is to all intents and purposes, completely unsolvable.

And that's "just" the fluid dynamics problem. And the continuum hypothesis isn't the only way to solve it. You could use Lagrangian mechanics if one were so inclined.

And these are just theoretical issues. We haven't even spoken about the practical difficulties. First and foremost, throw hope for an analytic solution out the window, because it's not going to happen. You've got to go with a numerical solution. Which brings up the next question of which numerical techniques to you use, and how accurately do you use them. You've got to factor in time, cost and cpu ability. You'll have to parrallelise the whole deal, and make sure it's accurate enough to remain stable for long enough to predict but you want but quick enough so that you'll get your answer before the actual event happens.

And last, but by no means least, once you've got that data, how do you analyse it? How do you even present it? Remember, we're talking about 3d vortices here, embedded in a globe. How do you make sense of it all. What points are of interest? What events are key? What can you learn from all this? What size font should the image titles have? How will you make a paper out of all this!?

Faced with such an operation, you're often better off performing a simulation when faced with a fluid mechanics problem, or in the case where simulation is impossible such as with Jupiter, just make a wild assed guess, sit back and enjoy the show.

Re:Collide?

[jmichaelg]

Societally, we have alot of collective experience modeling the types of problems you've described, and it would really only be a matter of modifying the initial parameters of our weather simulations to match those of Jupiter.

Codswallop.

Hurricane forecasts on earth diverge the further out you get. None of them called the right turn Katrina pulled in the Gulf of Mexico before she first hit Florida. On 8/25/05, this was the forecast:

This forecast is rather difficult since one of the more reliable models...the GFS...shows that the cyclone barely touches the East Coast of Florida before moving northward....while the outstanding GFDL moves Katrina south of due west across extreme South Florida and the Keys as a very intense hurricane. The GFDL scenario would be very dangerous for South Florida. This appears to be unrealistic at this time but because of the good past performance of this model...we must pay close attention to future model runs.

Notice New Orleans isn't even mentioned?
Those models had thousands of data point samples to work with including multiple flights into the heart of the hurricane and they still couldn't agree, let alone accurately forecast what happened to New Orleans. Those 'initial parameters' you so blithely dismiss have to be very accurate to make 24 hour forecasts, let alone forecast what's going to happen a month from now on a planet for which we have exactly zero weather buoys.

Re:Pretty Sweet "Amateur" Telescope ..?

[Tablizer]

What kind of strength/magnification do you need to see Jupiter in that resolution?

You are not going to get Hubble or Voyager level views. Many amatures now digitally enhence their images such that you see more in the photo than what the eye would see in the scope. One fairly recent technique is to take hundreds of digital images and then digitally average and realign the detail. The Earth's atmosphere wiggles and sometimes acts kind of like a magnifying lens. If you can capture these magnification spots when they occure and add them up, you get a nice photo.

Anyhow, I would guess that you need at least an 8-inch reflector or 5-inch refractor to see the two spots with recognizable detail. It also depends on sky conditions and viewer training. It takes a while to train the eye to see detail on planets thru a scope.

Re:Pretty Sweet "Amateur" Telescope ..?

[alienmole]

The answer is in the article - the photo was taken with an 11-inch telescope. If you're flush with cash, just go get one of these (Meade 12"), although you'll need to use it well outside of any big urban area, light pollution around cities kills viewing conditions. (You can get a similar scope for less money if you take more of a DIY approach, but then you have to learn much more about it. Scopes like Meade and Celestron are for people who just want to spend the money and get the results.)

Re:Pretty Sweet "Amateur" Telescope ..?

[helioquake]

There is a simple rule of thumb about magnification. It goes like this:

If your telescope is 10inch (~ 250mm), then your maximum magnification achievable with your telescope is up to 250 times. You can increase the magnification as much as you like (by the choice of an eyepiece), but it doesn't mean a damned thing when you go beyond 250x for the 10in telescope (it's like examining a photo on a magazine with 10000x magnifying glass; i.e., it's meaningless). For a 6inch telescope (~ 150mm), the max is 150x or so.

A 3in telescope is enough to see the Great Red Spot. For the small oval, it'd take a bigger telescope, I'd guess.

Mod parent up...

[sean.peters]

This is a very important point. We're talking about a simulation of a chaotic system. It has to be fed ground-truth data - lots of it - on a regular and frequent basis, or it will diverge rather quickly from reality. And with no weather stations, etc, on Jupiter, there's no way to gather the data.

Sean