Earth Simulator Now Predicting Hurricanes?

GeoGreg writes "The BBC is reporting that the Japanese Earth Simulator supercomputer is producing results showing that it is possible to model climate down to the level of severe weather events such as hurricanes. This computer has been discussed on Slashdot previously, and it sounds like at least some of the hype around this beastie was justified."

Earthsim do cool things

[lingqi]

Saw a TV program on it a while back; they showed research on researchers using EarthSim to see shockwave propogation if a large earthquake was to occur in Kanto, or more specifically within a short distance to Tokyo (which is probably the biggest worry to the entire Japanese seismelogical and to a lesser extent meterological bodies).

The conclusion was basically that Japan would be f***'ed if such was to happen, but that's rant for another day.

So, earthsimulator simulates a lot of things. I am surprised that they don't model nuclear blasts on them, because it certainly CAN. Or at least we just don't know about it.

One thing is for sure, though - I will attest that NEC definitely made a bundle over this =)

btw, for ppl who are in japan, you can schedule tours to the place. I havn't tried yet, but in case anyone is interested... (now that I think about it, wasn't there a story about this a while back?) but here is a link just for fun: visitor information [jamstec.go.jp].

and if you are brave enough for the same page in japanese, click here [jamstec.go.jp]. (The japanese page has a japanese map, which shows station names in kanji. I always found kanji station names to be more help, but that might be just me...

Re:Output

[girouette]

Each run of the model only offers one solution (called a deterministic forecast).

There is a technique called ensemble forecasting, whereby you run multiple instances of the model with slightly disturbed initial conditions and/or slightly tweaked model parameters. You can then examine the statistics of the ensemble to try and obtain information a deterministic forecast might not be able to give you.

Note that the goal in this particular case is not hurricane forecasting as such. The newsworthy information is that this is the first time that a climate model can be run at a resolution high enough that hurricanes become possible within the simulation. Short term models used for the daily weather forecast do this reasonably well already.

Re:Earthsim do cool things

[Raveolution]

Take a look to the authorized projects list for 2003 Here [jamstec.go.jp].

Re:Model

[Davak]

Really?

dictionary.com gives me...

Insure - To make sure, certain, or secure. (See Usage Note at assure)
Ensure - To make sure or certain; insure: Our precautions ensured our safety. (See Usage Note at assure.)

Usage Note: Assure, ensure, and insure all mean "to make secure or certain." Only assure is used with reference to a person in the sense of "to set the mind at rest": assured the leader of his loyalty. Although ensure and insure are generally interchangeable, only insure is now widely used in American English in the commercial sense of "to guarantee persons or property against risk."

I'm still not sure who is correct here. Please don't make me diagram the sentence. :)

Davak

Not really predicting per se...

[OneOver137]

but rather

"This means that we potentially have the capability to predict whether storms like Hurricane Isabel will be on the increase in future."

Just a trending or probability, not "a Cat 5 hurricane will form at this lat/lon and go here". Good start though, and we'll get there someday.

Re:No pussy-footing for NEC

[DrMindWarp]

The NEC EarthSimulator has been top of the Top500 list since the June 2002 edition. The main reason for its maintained top ranking is that it is a highly specialised, purpose-built machine. As far as I am aware, all the other listed machines come off a production line or are built from off-the-shelf, commodity parts. That's not to suggest one couldn't buy an EathSim off NEC if you made a suitable offer :-) If my memory serves me, a similar, highly specialised machine, the Japanese 'Numerical Wind Tunnel', was top of the list for quite a while too. It was also a vector processor based machine.

Re:10km resolution

[Katchina'404]

A cubic kilometer is the volume of a cube of 1km*1km*1km = 1km^3.

Therefore 10 cubic kilometers is the volume of 10 such cubes. For example, a volume of 10km*1km*1km is 10 cubic kilometers.

If you want a cube of 10 cubic kilometers, it would have a height (and width and depth, of course) of [cubic-root of 10]km, which is about 2.15km.

Re:10km resolution

[imsabbel]

actually, the 10km are not hight. A modern simulation uses 30-70 layers, spread across the 15-25km height they simulate

Re:Nonsense in article

[Anonymous Coward]

This isn't quite true.

The tracks in the UK aren't cheap and lightweight - the defining characteristic that causes them to buckle is that the rail sections are longer than those on the continent, and have less in the way of inter-section spacing for the rails to expand into when they heat up.

These measures were, as I understand it, introduced to reduce maintenance time on tracks and carriages, improve ride quality and increase efficiency generally.

The decision to base the tolerances round a (relatively) low maximum temperature is the mistake, if there is one. That said, rail buckling problems due to ambient temperature are quite predictable, and in the grand scheme of things, all it meant was some delays in hot weather, comparable to those we already had on the roads.

Not the end of the world, I think, and it's not entirely fair to imply rail buckling is a negligent planning issue (cheap and lightweight).

Now, on all the other negligence, you will get significantly less argument from me...

Re:Model

[91stst]

Meteorologist HAVE been doing this type of research for many years now. Here is the data you requested, the computed skill score of all current NCEP [noaa.gov] Operational weather models.

NCEP Skill Scores [noaa.gov]

If this doesn't convince you that much research is currently being done to improve weather prediciton, here is the fields most recent effort, the WRF model, a collaborative Operational/Research model.

WRF Model [wrf-model.org]

Keep in mind, the model can only resolve a solution near that of the actual resolution of the input data, i.e. observed conditions. This is why weather prediction is still an evloving science. Not only must these supercomputers solve the non-linear multivariate/ multidimenional equations governing the atmosphere, but scientist must also devise methods to quickly, and more importantly, accurately input the most recent data so the products can be made in a reasonable time for the public.

Re:Model

[Glock27]

the Japanese Earth Simulator supercomputer is producing results showing that it is possible to model climate down to the level of severe weather events

First of all, that is already happening with current weather models...those are the ones that predict hurricane paths and such. There were already predictions that this would be an unusually heavy hurricane season before it started - those were due to climate models that showed the ocean area responsible would be warmer than normal.

Predicting where hurricanes will appear and where they will go ahead of time (that is without looking at the current weather patterns while it is happening) involves that pesky chaos thing and good luck with that.

Perhaps what the person was trying to say is that this is the first time researchers have been able to run 10 km. (or 5, or 1) resolution models on a global scale all at once - and that is quite an achievement if so.

BTW, the point of all this is not to predict individual hurricanes or tracks. It is primarily to identify long-term climate trends. From the article:

"This means that we potentially have the capability to predict whether storms like Hurricane Isabel will be on the increase in future." - Professor Julia Slingo. (Hmmm, I guess she's from Soviet Russia;)

Re:Who needs a supercomputer?

[4of12]

small differences in the initial data manifest themselves as large-scale phenomena down the road.

A good point to emphasize when people are blindly clamoring for more computer power.

Lyapunov exponents [mpipks-dresden.mpg.de] for portions of phase space for a nonlinear system will cause this divergence.

So, yes, no matter how many bits of floating point mantissa you carry, or how precise your measure your initial conditions, exp(at) will inevitably grow if a > 0.

And, just in case anyone's proud of their accurate code and precise initial conditions, there's still Heisenberg to prevent you from measuring too much accurate information at the same time.

IIRC, someone once determined that a pencil, balanced on its point, would always fall within 22 seconds because of the inherent uncertainty in position and momentum that could be established initially.

Americans DO know the least about the climate

[Phronesis]

Americans are phenomenally ignorant about climate. Most do not even know why summer is hotter than winter. As the AAAS Project 2061 [project2061.org] describes it,

A classic video made at a Harvard University graduation illustrates what I mean (

Private Universe Project [learner.org], 1989). In the video, young graduates and faculty--still in their caps and gowns-- answer this question: Why is it warm in the summer and cold in the winter? Twenty-two out of 25 got the answer wrong. The typical answer was that it's warmer in the summer because the earth is closer to the sun. (The correct answer is that it's warmer then because the tilt of the earth, which remains constant as the earth orbits the sun, puts each hemisphere at an angle to receive maximum sunlight during the summer. The distance from the earth to the sun varies very little--actually, the earth is a little closer to the sun in January.)

More than half of the US population doesn't know that the earth orbits the sun or how scientists figured out that it does. Almost no one can explain what the phrase "orbits the sun" even means. Worse still, few can distinguish between an evidence-based explanation of how the physical world works and an opinion-based one.