Supercomputers Race to Predict Storms 184
pillageplunder writes "CNN has an interesting article on how different supercomputers from around the world are working to predict large storms tracks. The 3 days it takes now has been cut in half. Cool read."
Earth Simulator (Score:1, Redundant)
Re:Earth Simulator (Score:3, Informative)
Earth Simulator does - Atmosphere & Ocean Simulation, Solid Earth Simulation, Multiscale Simulation, and Advanced Precipitation Simulations. (And other cooperative projects).
Re:Earth Simulator (Score:4, Informative)
Re:Earth Simulator (Score:5, Informative)
A snip at $430 million...
Re:Earth Simulator (Score:2, Funny)
Re:Earth Simulator (Score:3, Interesting)
The place even looks cool http://www.ncar.ucar.edu/eo/what/arch1 [ucar.edu]
Can it predict the Presidential Election??? (Score:5, Funny)
Re:Can it predict the Presidential Election??? (Score:2)
Re:Can it predict the Presidential Election??? (Score:4, Funny)
Yes, the public demands finance disclosure (Score:2)
I'd like a little warning if Michael Eisner or Bill Gates is going to be our next president through a suprize number of "write-ins".
Re:Can it predict the Presidential Election??? (Score:2)
Re:Can it predict the Presidential Election??? (Score:2)
Twister (Score:5, Funny)
Re:Twister (Score:4, Interesting)
A talk I just gave a few days ago on this is found at the below link. Both in OpenOffice and PPT format. Note: the mpegs in that directory are BIG (1024x768) but they are very cool animations of supercells (raytraced with POV-Ray) and tornado-like circulations.
http://research.orf.cx/uw2004 [research.orf.cx]
Leigh Orf
Electrical Effects? (Score:2)
I'm modeling supercells that produce tornadoes
[Pardon me for taking advantage of your expertise]...So two questions have bugged me for a while.
Q1: Once I read where there seemed to be the possibility that tornadoes could be driven by magnetohydrodynamic forces [Nalivkin, 1963]. Is that plausible, credible, or are density variations due to thermal buoyancy enough to account for the observable physics of tornadoes?
Q2: What is it - really - that causes lightning? I've heard hand waving arguments about ice
the 3 days it takes? (Score:5, Informative)
I guess we should read articles before submitting them...
Re:the 3 days it takes? (Score:5, Funny)
Re:the 3 days it takes? (Score:2, Insightful)
And much less free on weather.com. Who decided to do that anyway? Charge for a best-guess on a 5-day forecast? I can see that for free on my rabbit ears on the TV.
Re:the 3 days it takes? (Score:2)
Just plug in your zip code [weather.com]
Re:the 3 days it takes? (Score:2)
Re:the 3 days it takes? (Score:2, Interesting)
Personally living in New Orleans (10 feet below sea level) it's comforting to know that the forecasts are only off by 400 miles now.
/SARCASM
Re:the 3 days it takes? (Score:2)
My thesis is that the confusion came from the last sentence that: "If we took three days to do a three-day forecast, it wouldn't be relevant."
Re:the 3 days it takes? (Score:3, Informative)
When a tropical system is moving very slowly, it is prone to wobble a bit, so on a time scale as short as 1 hour, there will be a considerable spread in possible movements.
The forecasts for Frances were in fact EXTREMELY accurate.
Stating the obvious (Score:3, Funny)
Way to pitch to the high-tech crowd CNN
But....... imagine a beowulf cluster of these weather predicting supercomputers.
Chris
More details on Fleet Numerical's iron (Score:5, Interesting)
Fleet Numerical's Previous iron (Score:2)
Pretty fast... (Score:3, Funny)
Re:Pretty fast... (Score:2)
Re:Pretty fast... (Score:2)
Re:Pretty fast... (Score:3, Informative)
Re:Pretty fast... (Score:2)
Fortran? Eyew. (Score:5, Funny)
Well no wonder weather prediction is so off!
I kid, I kid
Fortran, yay! (Score:5, Interesting)
Re:Fortran, yay! (Score:2)
Re:Fortran? Eyew. (Score:4, Informative)
Re:Fortran? Eyew. (Score:2)
Re:Fortran? Eyew. (Score:3, Insightful)
legacy algorithms, legacy programmers (Score:2)
Re:legacy algorithms, legacy programmers (Score:2)
I think the major reason Fortran is used is because of legacy algorithms (and legacy programmers!)
This is a common misconception, that Fortran is somehow a dead, legacy language. However, it so happens that this myth is even easier to dispel today, than on most other days. Why? Because news has just been posted to the comp.lang.fortran newsgroup that the Fortran 2003 standard has just been ratified.
Re:Fortran? Eyew. (Score:2)
Many of the most famous Fortran computational libraries have long since been translated into C and other languages, but when you have millions of lines of perfectly functional (and reasonably complicated) Fortran production code, moving to something like C is a difficult decision, especially when you have limited value in the move.
As someone else pointed out: C is close to
Cool distributed computing idea. (Score:2, Interesting)
Re:Cool distributed computing idea. (Score:2, Insightful)
Re:Cool distributed computing idea. (Score:2, Informative)
I'll save them the trouble... (Score:5, Funny)
Using Fortran, eh? (Score:2)
Re:Using Fortran, eh? (Score:2)
They're also primarily concerned with performance over other things; this would definitely influence their opinion if they were to adopt a new language (as opposed to maintainability and/or portability).
Re:Using Fortran, eh? (Score:2)
True, yup, that's usually the case.
> primarily concerned with performance
Hm. I'm not familiar with supercomputers... does Fortran have some sort of built-in support for being run on them? Like some sort of special internal JIT compiler or something?
Re:Using Fortran, eh? (Score:2)
Re:Using Fortran, eh? (Score:2)
Hm. I'm not familiar with supercomputers... does Fortran have some sort of built-in support for being run on them?
Yes, it does. There is a Fortran 95 language variant known as High-Performance Fortran (HPF), specifically targetted at coding for parallel computers. Fortran also sits very well with OpenMP [openmp.org].
Fortran does not need a JIT, since it compiles straight to machine code rather than intermediate bytecode.
Re:Using Fortran, eh? (Score:2)
What's more difficult is continually optimizing for the various machine architectures. The processor clocks are generally improving faster than the memory latency or network latency. So mitigating those is becoming a much bigger part of the puzzle.
Re:Using Fortran, eh? (Score:2)
> in about a day
Cool.
> What's more difficult is continually
> optimizing for the various machine architectures
Hm, that's interesting. Is that something that would be done in Fortran using some sort of pragma-ish hints? Or is it something the Fortran interpreter writers would be mostly concerned with?
Googling a bit reveals a couple of Fortran compilers [google.com]... seems like that's where the per-architecture optimization would happen. But maybe the "end-user"
Re:Using Fortran, eh? (Score:2)
> What's more difficult is continually
> optimizing for the various machine architectures
Hm, that's interesting. Is that something that would be done in Fortran using some sort of pragma-ish hints? Or is it something the Fortran interpreter writers would be mostly concerned with?
Googling a bit reveals a couple of Fortran compilers... seems like that's where the per-architecture optimization would happen.
Yes, most of the optimizations for specific hardware concern only compiler writers. Just like
Re:Using Fortran, eh? (Score:2)
I hope you understand now why Fortran is still used in scientific and banking computing.
Re:Using Fortran, eh? (Score:2)
What's the maintenance burden like for a large body of Fortran code?
Roughly speaking, about half that of a comparable C program.
Speed-wise, Fortran is about as good as it gets unless you want to go into asm. Fortran aliasing rules allow more aggresive optimization than C/C++ (although in this regard C99 achieves the same thing with restricted pointers). Also, the current Fortran version, Fortran 95, has a slightly matlab-like array language, where you can express many computations directly as whole arr
Re:Using Fortran, eh? (Score:5, Informative)
i) because most numerical weather codes are already written in Fortran. This means that people with the right scientific knowledge tend to be Fortran programmers, and makes porting a whole lot easier.
ii) Fortran compilers are the ones where the most work has gone into optimising the hardcore mathematical routines. Thus, the compiled code has traditionally been faster. This may no longer be true.
Re:Using Fortran, eh? (Score:2, Interesting)
HAL, where will the storm land HAL? (Score:3, Funny)
Re:HAL, where will the storm land HAL? (Score:2)
Except for the Butterfly effect where one little change can cause something major to happen elsewhere.
All that extra weight will change the butterflies flight pattern, causing all sorts of screwy weather conditions, the end of the world, Dogs and cats living together and mass tifoil hat wearng hysteria.
if you can find the joke above you aren't smart enough to read it to begin wit
Re:HAL, where will the storm land HAL? (Score:2)
Re:HAL, where will the storm land HAL? (Score:2)
Maybe we could terraform Mars this way.
Hmm, maybe I should be posting this to the USPTO instead of /., after all, I have an idea AND the implementation!
Best line (Score:5, Funny)
Journalism (Score:2)
Re:Journalism (Score:2)
But so so so right as well. I agree... but then, when is there ever NOT some kind of error in slashdot stories?
NOAA (Score:5, Interesting)
Re:NOAA (Score:2)
My long term goal is to have a PhD in CS and meteorology, probably combining both theses into one big project.
Relevant links from weather geek bookmarks (Score:5, Interesting)
http://www.weatherunderground.com/tropical/tracki
The NHC discussion of the model guidance for each storm is here, under 'discussion' for each storm:
http://www.nhc.noaa.gov/ [noaa.gov]
They explain why they're agreeing with or discounting each model in their overall forecasts.
Generally, it's difficult to find much prediction of hurricane tracks that doesn't come somehow from the NHC. This isn't because there aren't independent analysists, but because they try not to send mixed signals, which might lead to people not evacuating when they should. The raw information from the computer models is the closest you get to dissenting opinions, afiak.
You have to wonder.. (Score:4, Interesting)
Re:You have to wonder.. (Score:3, Insightful)
Re:You have to wonder.. (Score:3, Insightful)
Re:You have to wonder.. (Score:3, Insightful)
The boarding-up problem can probably be simplified with rigid mount points and locks on pre-fitted panels. I'm sure a solution can be designed for second story windows where it can be ins
There used to be a word for this. (Score:2)
Fortran and IDL (Score:2)
Re:Fortran and IDL (Score:2)
See the models (Score:5, Interesting)
Ivan [wunderground.com]
Jeanne [wunderground.com].
Since the pages auto-refresh, I've just been leaving them up in a tab in Mozilla and checking them every once and a while. Though the models aren't always accurate and tend to change a lot, they kind of give you a feel for where the storm is probably going to go.
Re:See the models (Score:2, Funny)
Re:See the models (Score:2)
A long way to go... (Score:2, Interesting)
Re:A long way to go... (Score:2)
Interestingly, they've still been off (100 mi. east w/ Charley, 300 mi. west w/ Ivan) and that's just because hurricanes a
Previous NY Times story (Score:2)
elment of improved prediction (Score:2)
Land seem chaotic (Score:2, Insightful)
Charley swerved just before landfall, Frances stopped dead in the water 60 miles off Florida, and Ivan "bounced" off Jamaica, shifting its path by 500 miles, none of which were predicted. Possibly, none of which are predictable. If you can't warn people where landfall will occur when it takes some non-obvious path, then what's really the
Re:Land seem chaotic (Score:4, Informative)
So, with land, you leave the realm of an initial value problem with relatively well-understood boundary conditions that you have with a storm over the ocean to a realm that has much-less-well-understood boundary conditions. The problem becomes much harder to close, much less solve. And with a system like the hurricane which REQUIRES good knowledge of the boundary (after all, the hurricane is fueled by latent heat release by condensation of water vapor which comes from the ocean), not knowing the boundary as well as you can makes prediction much much harder.
Charley's swerve was forecast by a good number of models, but NHC played the worse case scenario card a little too long by persisting on a landfall near Tampa Bay.
Frances' stop was due to a very irregular pattern, much like a saddle point. If you are pushed any direction, you get very different behavior. You can see that on the following model ensemble plot... there's a small cluster of 48 hour predictions that are slower than the others.
http://euler.atmos.colostate.edu/~vigh/g
Ivan's bounce off Jamaica is a seriously cool research topic, since Jamaica is a mountainous island. That big elevation change could make it more "visible" to the core of the storm (unlike the plains of Florida). This will be a serious research topic for decades to come. Many of the models did not handle it well (which isn't too surprising since Jamaica is a relatively small island and the models that are used frequently are global or near-global models). And some previous storms (Gilbert, 1988) didn't even notice Jamaica as they passed over, so experience is a split decision.
So, hopefully that sheds a little insight on this issue. Land is a BIG problem for track forecasting, and we're just starting to work out the kinks.
-Jellisky
Re:Fortran? (Score:3, Insightful)
There are a lot of existing, hightly tuned fortan algorithms out there and plenty of scientists to keep the code running.
Re:Fortran? (Score:4, Interesting)
Re:Fortran? (Score:2, Informative)
I saw in another post regarding my parent post that part of the reason is the tweaks for the fortran compilier being released.
I'm just trying to understand why they aren't moving to a more object oriented method of design for weather modeling. So they can drop in objects that don't require the entire code base to be recompile
Re:Fortran? (Score:3, Insightful)
As the old saying goes... (Score:2)
Pure and simple, as had been taught in my CS minor, OO-programming is very good. Except in numerical calculations, because you'll sit there and try to figure out these cutesy algorithms and objects and stuff that makes everything more complicated than it needs to be.
You're talking about, at its simplest level, integrating the following groups of equations in time:
http://amsglossary.allenpress.com/glossary / browse? s=e&p=30
It's a straightforward problem that re
Re:Fortran? (Score:2)
Despite some interest at Sun, in the end this was rebuffed and compute-intensive scientific Java never happened, unfortunately. It subverted some of their run-time requirements.
Basically all Java Grande wanted was a set of "relax this constraint" flags at compil
Re:Fortran? (Score:3, Interesting)
Even academic hpc facilities employ teams of experts to optimize code for the scientists.
You're right that there is a l
Fortran is faster (Score:5, Insightful)
Re:Fortran is faster (Score:2, Interesting)
Re:Fortran? (Score:2)
Fortran 95 offers a number of facilities unavailable in C, C++, or most other languages. This includes some built-in support for parallelism, simplified and powerful array processing, and a lack of aliasing problems. Fortran 95 is structured and modular, and can take advantage of a vast Fortran library comprised of tested, certified, and trusted numerical code.
It's a matter of using the right tool for the job.
Re:Fortran? (Score:2)
Many of the largest applications in the world are written in Fortran, both in the past and continuing today. I'd say that this would be presumptive evidence for scalability.
And there is nothing that is more open than Fortran. There are
Re:Fortran? (Score:2)
But I'm still puzzled by your original comments. I'm not interested in arguing about what lan
Re:Fortran? (Score:2)
I'm sorry, but you are flat wrong about its portability. I know because I myself write programs that I have myself ported to probably more different kinds of machines than still exist
Re:Just Distribute the Load... (Score:2, Insightful)
- dharhas
Wouldn't work. (Score:4, Insightful)
If you're waiting for those results at Internet (Latency: 100ms) speeds instead of intra-system speeds (latencyL 1 us) it takes you 100,000 times as long to get your data.
With SETI, all you do is get the data once, compute, and send back the answer.
Re:Just Distribute the Load... (Score:2)
SETI works really well because a measurement from one quadrant of the sky doesn't affect the measurement taken in another.
A one degree change in one quadrants prediction affects all the quadrants immediately surrounding it. This data has to be communicated to the surrounding areas, which in turn affect them, and ripple through the entire model. This communication burden flattens even beowulf levels of connectivity, let alone a desktop on a broadband connection. This is why IBM still mak
Re:WOW Hong long (Score:2, Insightful)
Re:storm tracking doesnt prevent storms huge impac (Score:2, Insightful)
Did you ever consider that things happen for a reason? Like balancing global heat loads and adjusting the water vapor cycle?
So instead of having a bunch of light to heavy storms, we'll end up with having ONE BIG MONSTER that we *can't* stop.