By Steven Goddard
I recently had the opportunity to attend a meeting of some top weather modelers. Weather models differ from climate models in that they have to work and are verified every hour of every day around the planet. If a weather model is broken, it becomes obvious immediately. By contrast, climate modelers have the advantage that they will be long since retired when their predictions don’t come to pass.
Weather and climate models are at the core very similar, but climate models also consider additional parameters that vary over time, like atmospheric composition. Climate models iterate over very long time periods, and thus compound error. Weather modelers understand that 72 hours is about the limit which they can claim accuracy. Climate modelers on the other hand are happy to run simulations for decades (because they know that they will be retired and no one will remember what they said) and because it provides an excuse to sink money into really cool HPC (High Performance Computing) clusters.
But enough gossip. I learned a few very interesting things at this meeting.
1. Weather modelers consider the realm of climate calculation to be “months to seasons.” Not the 30 year minimum we hear quoted all the time by AGW groupies. That is why NOAA’s “Climate Prediction Center” generates their seasonal forecasts, rather than the National Weather Service.
2. The two most important boundary conditions (inputs) to seasonal forecasts are sea surface temperatures and soil moisture. No one has shown any skill at modeling either of those, so no surprise that The Met Office Seasonal forecasts were consistently wrong.
For example, just a few months ago the odds of La Niña were considered very low. Compare the December forecast with the May version. How quickly things change!
SST modeling capabilities are very limited, and as a result seasonal weather forecasts (climate) are little more than academic exercises.
Oh and by the way, Colorado will be exactly 8.72 degrees warmer in 100 years. But they can’t tell you what the temperature will be next week.
“If I don’t understand it, it must be simple.”
– Dilbert Principle
In the top picture, which boxer is weather and which one is climate? What do readers think?
Might want to use the June version of your later graph, NASA now forcasts ENSO below -2.5 later this year, it’s on page 27 of this .pdf: http://www.cpc.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf
I prefer a comparison to David and Goliath, my trusty sling has a smooth and rounded pebble freshly loaded…. as the Goliath (or IPCC) strides into view…. .
As to models;
http://theresilientearth.com/?q=content/ocean-conveyor-belt-dismissed
Obviously the big guy is Climate, as Climate defines the outliers of daily weather.
While I consider myself a AGW skeptic, I don’t think the “if they can’t tell you what the temperature will be next week, how can they know what it will be in a 100 years?” arguments do any service to spreading critical thinking over this issue.
Unless people modelling climate are simply taking weather models and running them with a larger time step, which I very much doubt is the case, the argument is ridiculous. Similar to saying we can’t know the pressure of a gas is, because we can’t even predict with certainty what the trajectory of a given molecule will be…
jcrabb says: Climate defines the outliers of daily weather
JC not quite sure what that means, however, I have never been someone who is happy to separate climate from weather. To me, climate was always just another word to describe weather but in a very loose, non-descript way. Climate, the word, allowed the formation of another university/government department for creating acedemic, non-productive jobs for school children who never want to grow up and “go out to work” as my dear old mother used to tell me. Although Anthony succinctly describes the difference between weather and climate models in terms of parameters used, the climate parameters he describes also affect weather when then affects the climate. See what I mean?
I think it’s the other way around. Weather is in constant motion, more aggresive, volatile, and packs a punch at short notice. Clearly the heavyweight.
Climate, however (despite the raving predictions of the AGW lobby) continues to do it’s own sweet thing at its own pace, and really doesn’t need to be that dynamic – long time, small, cyclical effects.
Thank you for mentioning the compounding error issue.
I try to explain to friends and colleagues about floating point representation and problems arising from that. I dipped into some of the online models and some of the CRU code and it seems to all rely on the standard number handling of the hardware and software platform.
Anyone who needs to know about it should read Knuth’s “Art of Programming”, he deals with the issue with typical humour-tinged clarity. While you’ve got it out, check out his section on random numbers. I believe (not sure) that most of the models use random numbers to some extent, and yet we never learn about the actual algorithms used in these models.
“Weather models differ from climate models in that they have to work and are verified every hour of every day around the planet. If a weather model is broken, it becomes obvious immediately. By contrast, climate modelers have the advantage that they will be long since retired when their predictions don’t come to pass.”
This is the one statement that has totally nailed the problem. Weather science is so real, so verifiable and for the most part trustworthy. On the other hand, but in the same field it is incredible that climate modelling is nothing more than junk science. And the reason it is junk science is that what is describe above is the scientist will be long since retired or dead when their predictions don’t come to pass. And this is how science became prophecy.
But even now, six months after climatgate, Michael Mann worried about his own legacy, is putting out feelers to the public and science at large that tell us his hockey stick models are not to be taken as the basis of climate change. Amazing, simply amazing. Even Michael Mann now sees climate modelling as junk science, even though he is going in a round about manner of telling us. All we have at this moment in science is weather.
Equatorial Pacific is the area where the Earth magnetic fields vertical component GMFz changes its polarity. There is a possibility that the movement of the geomagnetic Equator in relation to the geographic Equator has some influence on the Equatorial currents of the area.
http://www.vukcevic.talktalk.net/LFC20.htm
Similar relationship between the GMFz and temperature anomaly has been established in the Arctic ocean.
http://www.vukcevic.talktalk.net/NFC1.htm
Got interested lately in the whole climate thing and can’t help but wonder if weather (and thus climate) is largely dependant on what the oceans are doing. So instead of studying the atmosphere shouldn’t the oceans be the prime subject of climate study.
Seeing the cyclical behaviour of the major ocean driven events like El Nino, PDO etc. have the variations in the gravity pull of the moon been studied?
Seeing the daily tides and the large variations therein you would expect an influence (perhaps large).
I understand the variations in the moons orbit give some 50% variation from the average gravity pull. Maybe Milankovitch cycles have an influence on the combined gravity pull of the sun and the moon as well.
In any case the gravity pull changes cyclically, and is maybe worth looking into?
OT:
Don’t worry, eat bananas and all will be well:
http://www.guardian.co.uk/environment/green-living-blog/2010/jul/01/carbon-footprint-banana
Bananas? Quite ….
They are both climate- within uncertainty.
Several years ago now, I was part of a discussion panel with a local TV meteorologist. I was doing computer modeling of astronomical phenomena at the time; he was discussing weather forecasting models, I was talking about the difficulties of complex, long-time-span models.
The forecaster related the story of how his own mentor, who was a very popular meteorologist on TV, back in probably the late 70’s or early 80’s, resigned his position rather than give a 7-day forecast. He refused to be part of something he felt was a hopeless waste of time.
The guy on the panel said 3 days is believable, 5 is a stretch, but hey, everybody wants a 7-day outlook, right?
Jeff
Climate is maybe more like the ring than the fighters who stumble about, inside the boundaries… Actually, seriously, “climate” is more like predicting the probability distribution of the outcomes of 1 million fights, whereas “weather” is predicting the outcome of the next round of a single fight.
Generally speaking, it would seem that the author does not quite understand the fundamental difference between weather and climate, or how climate models work or what their output and purpose are. So, IMHO, this article falls flat on its face – just like the small boxer seems to be on the verge of doing.
Steven, Your Good!
It all comes down to what are the rules and what are the boundries that separate the two fighters assuming the arena is the world. What label do you put onto each fighter depends also on what you would like to achieve. Most people would assume climate to be the “big guy” with the power, money and backing of governments and the assumption that they are invincible or supreme in the science. In a short term duration (such as the science now) the energy and power would be a good bet but over a longer span, they tire out and fall apart. Weather will still continue on way past the climate models due to the lack of total understanding ALL the input and not staying “hyper-focused” on one area such as CO2 or strictly temperatures.
This same situation can be said for AGW and the “Deniers”(enlightened ones? truth finders? hmmmm)
Thank you Steve for summarizing, in a few paragraphs, my personal view of the current state of numerical climate modeling, based on my 20+ years of experience in academic and industrial high-end computational fluid dynamics.
“Weather and climate models are at the core very similar…”
This, of course, is correct, but the most important similarity is that the differential equations both groups are solving** are non-linear. There are NO guarantees of having ANY solution, much less the CORRECT solution. Moreover, no where in the climate modeling literature has anyone attempted to show that the climate problem is well-posed and is indeed solvable by numerical means…
**The exception here is NASA GISS. Nobody knows what equations they’re solving with Model E…
The smaller boxer would be climate, because he, being more fit would be able to outlast his opponent, wearing him out essentially.The larger boxer (weather) might seem to dominate at first, but would eventually succumb to the smaller boxer’s speed, agility, and endurance.
In the battle between the climate Alarmists vs Skeptics/Climate Realists, the latter would be represented by the small boxer. The Alarmists appear to be exhausted now, lashing out furiously but ineffectually in their last-ditch efforts to survive.
Man’s effect on climate could be represented by a fly buzzing about climate’s head.
surferdave :
“I believe (not sure) that most of the models use random numbers to some extent, and yet we never learn about the actual algorithms used in these models..”
I’m not sure this is the case. For example, CCSM3 has a 226-page technical paper describing the equations in the atmospheric model (CAM3 – the atmospheric component of CCSM3) – http://www.cesm.ucar.edu/models/atm-cam/docs/description/description.pdf
And more about models at Models, On – And Off – The Catwalk – Part Two and Models, On – and Off – the Catwalk – Part One
well, here’s hoping the moderator can fix my tags in the previous comment and close out the bold tag at the start (wasn’t trying to shout)… thanks moderators!
If you think about it, an accurate climate forecast would be totally dependant on deterministic long range weather forecasts, and that can only be done by predicting changes in the solar signal.
‘To punch below one’s weight’ is to achieve or perform at a level lower than should be expected based on one’s preparation, attributes, rank, or past accomplishments.
The big guy is climate.
Piers Corbyn seems quite good at predicting WEATHER a season or so ahead.
By which I mean extreme weather rather than ‘it’ll rain a bit today and be sunny tomorrow’.
His models use solar, geomagnetic and atmospheric parameters and I didn’t see him document anything about oceanic contributions yet. He may do, I may just not pick it up.
Jaime says:
July 1, 2010 at 2:46 am
” … the argument is ridiculous. Similar to saying we can’t know the pressure of a gas is, because we can’t even predict with certainty what the trajectory of a given molecule will be…”
The gas is not a chaotic system, however the atmosphere, oceans, and landmass is.
This is REALLY easy.
Weather is anything that can just be brushed under the carpet out of view because it is inconvenient, like predicted mild winters that turn out to be exceptionally cold.
Climate on the other hand is all the “WussThanWeThort” things that prove conclusively how evil mankind and CO2 really is. Like the summer heatwave in 2003 that killed 30 billion French people or whatever it was claimed to be.
Simple, really!
Jaime
Climate models are basically extended weather models. They have to be, they are modeling the same atmospheric and oceanic processes.