The Models Fail, Simple Physics, & a Primer on the Oceans
Posted by greg2213 on December 6, 2010
No, they don’t accurately hindcast (retrocast) and they don’t accurately predict and it’s probably because such predictions are impossible due to the extreme number of variables and the chaotic nature of the system.
Update: While the “model” below is interesting, to me, WUWT has a new post on simple physics and how it fails in regards to the climate discussion.
But as every engineer knows, these simple laws often do not work when reality gets messy, as it usually is. Simple physics says that if I drop a ball and a feather they will fall at the same rate.
In reality my feather blew up into a tree.Here’s the rest: Simple Physics – In reality my feather blew up into a tree
Update: This also explains the “simple physics” quite nicely:
And yes, “simple physics” adds disclaimers along the lines of “..at the same rate, in a vacuum…” This, of course, proves the point that there is nothing simple about the climate system. It’s entirely possible that climate cannot be modeled on anything other than a general scale.
I think I/we can look at it this way, though this is probably bad…
Take a jar/container/holding device of 99 marbles of differing sizes plus one golfball.
The exact mass of each marble and the ball are known to an arbitrary precision, as are the exact dimensions of the “jar,” height of the jar, etc.
Take a 4×8 plywood sheet, lay it on the floor, and add walls to keep the marbles from rolling off the thing. The exact properties of the sheet are known, as are the height of the walls. Heck, make the sheet marble, titanium, glass, or soft sand.
Place the jar at an exact position and pour the marbles onto the plywood at an exact rate in an exact manner.
Write a computer program with all the known data and use it to predict the exact final position of the golf-ball. Add in the exact position of each of the 100 objects as they start to fall. Heck, predict the exact position of all the 100 objects.
wait for the marbles to settle. Check the exact position of the golf ball and marbles.
Do this 10,000 times. How many times was your model correct? Obviously if the definition of “correct” is “some position on a 32 square foot plywood/marble/sand surface” then it’ll be correct all the time. If your definition of “correct” is to a one inch square, then chances are you’ll be right a very small number of times with over 4600 squares. (32*144 = 4608)
We’ll assume that with the hard surface the golf ball has an equal chance of landing anywhere on the surface, which may or may not be the case as it may or may not bounce all over the place. If it isn’t the case then add the odds to your program. Obviously with a sand surface it won’t be the case.
With a one foot square you will likely be right about 10,000/32 times. With a sand surface you can probably ignore a lot of squares since the balls won’t roll very much. Increase the precision of the prediction and the number of times that you are “correct” will decline, though you may be “almost” often enough. Define “almost.”
Personally, I don’t think modeling climate is any simpler than this. While the surface seems to be bounded to +- 10C or so, there may be more marbles and you’re trying to predict an exact outcome. Good luck.
So why not take a flying triple-spin leap? My prediction is that until such time as we really drop into the next ice age the global climate number will be +- 2 degree C from where it is now, with +2 being vastly better for humankind (and plant/critter kind) than -2, and also better than it is now.
Ok, enough silliness. Back to work.
The Earth is essentially a water planet.
Over 70% of its surface area is covered by oceans, seas, and lakes, while a further 5% or so is covered by glaciers and ice caps resting on land areas. More than two-thirds of this water area is located in the southern hemisphere, and the ocean masses are typically 4 to 5 kilometres deep. With the Earth being over 75% covered by water in one form or another, it follows that the response of this 75% to any increase in greenhouse gases will be decisive in determining to what extent a warming, if any, will occur.
The atmosphere cannot warm until the underlying surface warms first. This is because the transparency of the atmosphere to solar radiation, (which is a key element in the greenhouse warming scenario), prevents the lower atmosphere itself being significantly warmed by direct sunlight alone.
The surface atmosphere therefore gets its warmth from direct contact with the oceans, from infra-red radiation off its surface being absorbed by greenhouse gases, and from the removal of latent heat from the ocean through evaporation. This means, therefore, that the temperature of the lower atmosphere is largely determined by the temperature of the ocean. In other words, it is necessary for the oceans to warm up first before the overlying atmosphere can warm.
The rest: THE DEEP BLUE SEA
On the ocean being a giant heat engine: The Constructal Law of Flow Systems
That article is based, in part, on this paper.