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NASA's Hurricane Model Resolution Increases Nearly 10-Fold Since Katrina
zdburke writes: Thanks to improvements in satellites and on-the-ground computing power, NASA's ability to model hurricane data has come a long way in the ten years since Katrina devastated New Orleans. Their blog notes, "Today's models have up to ten times the resolution than those during Hurricane Katrina and allow for a more accurate look inside the hurricane. Imagine going from video game figures made of large chunky blocks to detailed human characters that visibly show beads of sweat on their forehead." Gizmodo covered the post too and added some technical details, noting that, "the supercomputer has more than 45,000 processor cores and runs at 1.995 petfalops."
It's a five fold reproductive tube
But really, it was the accuracy that was the problem all along.
Nice and all, but the model resolution was never the problem. E.g. Katrina was going to hit whatever model we had, with not much warning. The problem was the response.
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They didn't say they accuracy of their predictions had increased 10-fold. Only that their computing power has. Unless the accuracy of the input data has increased, all we know for sure is that their electricity bill is going to be higher.
Now all their predictions are simply: It's gonna Rain Sideways!
rewriting history since 2109
How fast can 45K cores do auto-correct?
What the hell is a petfalop?
HAHAHA!
Hooray beer!
Why are typos so much funnier when drunk?
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It's been estimated that if you had temperature, pressure, and humidity readings for every cubic foot of atmosphere, you could only predict weather to about a month...if you had the computer power, which you wouldn't.
That's the problem with the famous butterfly effect. The tiniest deviation of a single molecule changes the weather patterns months down the road. The microscopic movements dictate large scale events down the road. The error scientists made was assuming small changes dissolved into statistical irrelevance, and that statistics of large masses of air drove particular day-to-day weather patterns. They drive climate, not weather (though particularly severe weather events can shift climate to other strange attractor basins, too. A bad volcano or two and a summer where snow doesn't clear and an ice age can come on in a year or two.)
Weather is the pattern of glitter on the water, not a statistical analysis of the pattern.
(-1: Post disagrees with my already-settled worldview) is not a valid mod option.
I was wondering about that. I don't do mathematical modeling, and my wife, who actually does mathematical modeling is currently on an airplane over the Atlantic coming home so I can't ask her.
Does higher resolution in the model necessarily translate to more accurate predictions? Let's even say that the input data increases. In highly unstable systems, where boundary conditions, stability and error correction are going to have outsized impact on the model, does higher resolution mean more accurate predictions. Or, as you say, does it just mean they've got more powerful computers.
If anyone can answer this, please, no Math. It will be like casting pearls before swine, with me as the swine.
You are welcome on my lawn.
The school buses didn't belong to the school district, much less the city. These free-market idiots who believe in privatizing everything to make it more expensive and less efficient had ensured that there were no school buses available to move people. Nagin was an idiot, but that was one failure that can't be laid at his feet.
More disturbing to me was that Cuba had sent a ship full of doctors and Venezuela had sent a tanker full of fuel for hospital generators, and both were turned back by the Navy. Most of the hospitals stayed staffed by nurses and candy stripers (the doctors could afford to evacuate) until the All Clear, and the generators ran out of fuel until Halliburton trucks could get to them (even domestic trucks of donated fuel were turned back because only authorized vendors selling at elevated prices were allowed in).
"Think about how stupid the average person is. Now, realise that half of them are dumber than that." - George Carlin
Thats where the eye of the storm went over. Gulfport/Biloxi was completely destroyed but lets keep posting information about just New Orleans because.. ya know.
Actually we can predict pretty damn well. It depends on what you compare to: perfection, or what we could predict thirty years ago, or seventy-five years ago.
We're living in an era of rapid improvements in weather forecasting in terms of accuracy, precision and scope. Back in the 70s there was a perennial science fair project in which the student compared the accuracy of tomorrow's weather forecast to simply assuming that tomorrow would be like today. The answer back then was, it was about equally accurate. Today would be a totally different story. The forecasts we get for three days out is better than the forecast we used to get for tomorrow back in the 70s; people just haven't updated their thinking.
It's not surprising when you realize that the difference is satellite tracking, meteorological data networks, and incomprehensibly more powerful computers. Today's smart phones are roughly as powerful as the supercomputers of the 1980s.
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If one is approaching, be sure to stock up on plenty of munchies, beer and weed. Use a bunch of car batteries through an inverter to avoid the clanking, rattling generator.
What else is there to know? I mean, besides not building matchstick homes so close to the open seas where there are hurricanes? And certainly not below sea level! What were they thinking? Trying to save a few pennies? You don't need high resolution to know that doing stuff on the cheap is pretty risky business. Though I'm sure the pictures look nice.
“He’s not deformed, he’s just drunk!”
What was wrong with Katrina-era models? We knew several days before it hit shore how bad Katrina was going to be... The issue was the pitiful evacuation, not the lack of advance notice.
Ken
It's only 1.995 pet falops because one of the falops got its tail caught in a closing screen door and lost the tip. Maybe it'll grow back.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
I'll bite.
With a higher resolution you can begin to resolve some of the dynamics of the eye wall, which gives you a much better idea about how the storm's intensity will develop.
There was a very good wunderground blog post about this last week with a /. story about it.
~.~
I'm a peripheral visionary.
I'm going to agree with the AC above me and say yes, increasing the resolution will generally result in a better forecast. There are two areas that generally can improve weather models: better initial conditions for the model and higher resolution.
Hurricane tracks are primarily influenced by large areas of high and low pressure and the accompanying upper-level winds. Even a coarse model with grid points every 50 km will probably produce a reasonably accurate representation of large features. Adding to the resolution might help a bit, but it's not likely to improve the forecasting of hurricane tracks that much.
Hurricane intensity, however, is driven by the storms in the inner core of the hurricane. They typically form a ring around the eye of the storm and are referred to as the eyewall. They're basically thunderstorms but without a lot of lightning, typically less than 10 flashes per hour. Inside those storms, large amounts of water vapor condense, and when this happens, latent heat is released. The latent heat comes from the energy that's no longer being used to keep the molecules of water apart once the state changes from gas to liquid. This heat warms the air, causing the column of air to expand upward. When this happens, you get high pressure at the top of the hurricane, and air spirals out from there. Air is flowing out of the core of the storm at the upper levels, so there's less air to press down on the surface. This causes the surface pressure to fall and the hurricane intensifies. These storms are small, on the order of 20 km across, but they're really important to predicting hurricane intensity. If the model has its grid points spaced 50 km apart, you may not have any grid points to resolve the storms. One of the newer hurricane models, the HWRF, now goes down to a grid point spacing of 2 km. There are a lot more grid points from which to represent the storms in the inner core of the hurricane. That allows much better prediction of hurricane intensity.
For a few decades, hurricane track forecasting had improved quite a bit as the global models could better predict the high and low pressure systems that drive hurricane tracks. During a lot of that time, predictions of hurricane intensity didn't get a lot better. Only within the past decade or so have we seen bigger improvements in forecasting hurricane intensity. That's largely a result of more computing power and models that are able to directly simulate what's going on in the inner core of the hurricane.
I do agree with the AC that it's not as simple as changing a couple of numbers in a configuration file to get a higher resolution and automatically getting a better forecast. There is something of an art to modeling. Even with a really high resolution grid, there are still processes that can't directly be simulated or are on a smaller scale than the grid. We still have to parameterize those. But improving the resolution is generally a good thing.
M-I-Z
kU still sucks!
NHC forecasters consider a very large number of models when making hurricane forecasts. Many of these aren't run by NOAA. Here's an old list: http://www.nhc.noaa.gov/modelsummary.shtml. NHC has used the NOGAPS model for a long time. NOGAPS is a global model developed and run by the US Navy. If a NASA model can make useful predictions, NHC forecasters will certainly use it.
M-I-Z
kU still sucks!
It is nice to know a disaster will strike, but it is another story to handle it properly. Is there any progress here, or will we see again medias calling theives the people that seek survival by taking food from closed supermarkets?
Thanks, very informative post. Spatial resolution has a major effect on the accuracy on any FEA model. Taken to the extreme, if the block size in a FEA simulation is comparable in size to the Gulf of Mexico, then you won't see hurricanes in your model. One consideration is that the size of a hurricane does not necessarily indicate storm intensity. Cyclone Tracy that hit Darwin in the 70's was an unusually small cyclone, IIRC less than 50km across, but the winds were amongst the strongest ever recorded in Darwin, strong enough to flatten it. I believe Darwin is now a Mecca for storm modellers hunting data, during the wet season a tropical storm conveniently develops over Darwin bay every afternoon, it's like clockwork, locals have a name for it, IIRC it's called "Harry".
To those who are bringing up the "chaos" issue, yes we will never get accurate forecasts more than about a month in advance. Since Tracy hit Darwin in the 70's accuracy has improved from 3 days at best, to 10 days at best, that's extremely useful for the military and commercial logisticts. Predicting cyclone tracks is notoriously difficult but it seems these days that tracks for the next 5 days are usually pretty accurate.Track predictions for any number of days above 1 in the 70's were almost useless. New Orleans had at least 3 days warning, everyone was told a massive storm surge was expected, hell I was 10,000km away in Australia and heard about the expected surge days before it hit. New Orleans was not a natural disaster, it was the "worse than useless" response from authorities that was the problem. Darwin suffered the same "lack of response" problem in the 70's, but to be fair it was a very remote place back then.
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The "slashdot paradox" when it comes to the workings of the biosphere is about politics, not science. To many otherwise intelligent people, science that contradicts their political/religious beliefs cannot possibly be "real" science. We all suffer from bias, but to observe an extreme example of this type of bias you need look no further than, Rhodes Scholar and current Prime Minister of Australia - Tony Abbott.
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
"the supercomputer has more than 45,000 processor cores and runs at petfalops."
So what happened here? Is this like the cubic centimeter limits for motors where if you go over a size limit new rules go into effect? Like you don't have to pay to register your supercomputer if it is under 2.000 "petfalops" (whatever the hell that is)?
...or did someone realize after it was built that Excel had been rounding on them, and they were 113 processors short of the 2 "petfalops" system specified in the bid?
Not any more, the Alternet Forums are long gone. One of the regular posters there owned a petroleum distributorship in Pennsylvania. They drove a truck of diesel down with the intent of donating it to one of the hospitals, but were turned back. They were specifically told that only trucks contracted by Halliburton or KBR (can't remember which) were being allowed in. The only links I can find at the moment are for the Walmart trucks full of water being refused entry, and qualified first responders being made to wait for a week or more and never being allowed entry, and the Coast Guard vessel that wanted to offload 1000 gallons of diesel to trucks supplied by one of the parish governments and not being allowed to.
"Think about how stupid the average person is. Now, realise that half of them are dumber than that." - George Carlin
assuming the number of hurricanes doesn't decrease with the solar slowdown:
Don't worry, you will have other hurricanes.
All you need to know is how far from the coast you need to live. If people are stupid enough to live close to hurricane-prone shores, they are welcome to die for their housing choice.
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