Quantcast
Channel: Comments for Climate Etc.
Viewing all 147818 articles
Browse latest View live

Comment on The albedo of Earth by captdallas2 0.8 +/- 0.2

0
0

I believe he meant “calibrated” :)


Comment on The albedo of Earth by David in TX

0
0

Willard’s replies would need much quality improvement to rise to the level of specious.

Comment on The albedo of Earth by AK

0
0

I doubt that: […] can be substantiated, considering that there are more possible games of Chess than there are atoms in the universe, there are a bit more water droplets in the hydrological system than there can be pieces on a chessboard.

“Look! A squirrel!”

Comment on The albedo of Earth by JustinWonder

0
0

Ak writes, “The current approach, based on creating a computerized model of every interacting particle, would have to drill down to the scale of an individual water droplet or aerosol particle before it would have any realistic chance actually replicating the behavior of the global system.”

Actually, it doesn’t matter how small the scale. According to chaos theory, the difference between states can be arbitrarily small and yet the difference between future states, as the dynamical system evolves over time, can be large. So, using ever more powerful, and expensive, hardware to get a more precise prediction based on a more precise initial state is a fool’s errand. Personally, I’m ok with that, as long as they don’t spend public money or money that has avoided taxation, via donations to NGOs that are defacto political, to finance those fool’s errands.

A view of the earth from space shows ocean currents and eddies that look just like an image out of Mandelbrot’s book – scale invariant and turbulent.

Comment on The albedo of Earth by ...and Then There's Physics

0
0

Mi Cro,

I will point out that in the surface data I have it is missing.

I don’t understand what you mean by this. What is missing and why is it that few others seem to think that something crucial is missing?

Swood1000,
I don’t really think the paper is saying anything about a stabilising feedback. I think it is simply illustrating that the albedos of the two hemispheres are essentially the same and that this may be a consequence of some kind of hemispherical energy balance. I don’t think that this implies that the albedo will adjust to counteract some change in forcing. If anything, if the NH albedo is dominated by land (which is pretty hard to change) it might be suggesting that it is difficult for the albedo to change at all unless you change the land albedo in the NH.

Comment on The albedo of Earth by Lucifer

0
0
<i>The water vapour content of the atmosphere is largely set by the Classius-Clapeyron relation which indicates a dependence on temperature</i> Water vapour content is <b><i>limited</i></b> by Clausius–Clapeyron, but not necessarily set ( or the Sahara would be a lot wetter ). A dynamicist might focus on the motion of water vapour ( and precipitation ). Probably both aspects pertain to 'climate change'. But imagine an ocean and atmosphere without wind or turbulent flow, but only molecular diffusion. Over a long time, would water vapor diffuse to the limit of Clausius–Clapeyron, such that relative humidity was 100% everywhere? It would seem so, but average relative humidity is closer to 50% instead. Now, I know the speculation is that relative humidity will remain roughly constant through modeled warming. That may be, but it is still subject to the unpredictable dynamic flow which keeps the atmosphere from being saturated currently.

Comment on The albedo of Earth by nickels

0
0

One thread to rule them all……

Gotta be careful with supercomputers getting bigger tho. Diminishing returns.
For one the (huge) supercomputers are essentially regular(ish) computers connected by a very fast network. But as you get more of them the communication cost between nodes becomes the bottleneck. And if you are solving any linear systems your preconditioning goes to squat since this is almost always does in blocks per node (the little computers) and get lets efficient as you get more blocks.

Also, as spatial resolution goes down, time step must go down as well for accuracy and stability. I forget the orders, and the argument (maybe someone can fill in), but the scaling is not good. As I recall higher order spectral methods become more efficient.

I trained in this stuff and now dont remember it. But take away is that bigger has limitations….

Comment on The albedo of Earth by Danny Thomas


Comment on The albedo of Earth by ...and Then There's Physics

0
0

Lucifer,

Water vapour content is limited by Clausius–Clapeyron, but not necessarily set

Okay, I was trying to think if my wording could be pedantically criticised. I didn’t think hard enough :-) Yes, “limited” is more appropriate than “set”. As you say, the current view is that RH will remain roughly constant as we warm. This may not be true, or there may be well be things that add complexity, but I don’t think that there is anything in this paper that suggests some major flaw in this basic picture.

Comment on The albedo of Earth by AK

0
0
<blockquote>Also, the notion of paradigm is epistemological, not semantical, so the claim that we’d need a paradigm shift in semantics would deserve some clarification.</blockquote>From <a href="http://en.wikipedia.org/wiki/Semantics" rel="nofollow">Wiki</a><blockquote>Semantics (from Ancient Greek: σημαντικός sēmantikós, "significant")[1][2] is the study of meaning. It focuses on the relation between signifiers, like words, phrases, signs, and symbols, and what they stand for; their denotation. Linguistic semantics is the study of meaning that is used for understanding human expression through language.</blockquote>For instance, in Newtonian physics, "mass" meant some invariant, a property of certain classes of object/substance. With special relativity, the <b>meaning</b> of the word, and mathematical constructions using it, changed. (There were now <b>two different types</b> of mass.) Any paradigm is really a <b>semantic</b> construction. <a href="http://en.wikipedia.org/wiki/Epistemology" rel="nofollow">Knowledge</a> is of no value without a clear definition of what the statements purportedly known <b>mean</b>. Oh and BTW, I didn't say “<i>paradigm shift in semantics</i>”, I said “<i>new semantic paradigm</i>”. New terms, with new meanings, describing referents currently not part of climate science.

Comment on The albedo of Earth by anng

0
0

Lucifer,
” to say albedo would negatively feedback if another forcing was imposed”

The authors seem to be ignoring forcings and looking at what’s actually happening and tryng to differentiate between reflections from Earth’s surface and Land when they say
“The model provides a way of incorporating our most up-to-date global data to isolate surface contributions from atmospheric contributions. When applied to TOA flux data collected from currently orbiting satellites together with matched surface flux data inferred from these and other satellite observations, a number of surprising features about the planet’s albedo are revealed”

and when they conclude “… simple models with an albedo overly sensitive to surface temperature”

If you assume the wording is designed not to raise the hackles of warmists, then you have to read between the lines.

Comment on The albedo of Earth by Willard

0
0

Instead of correcting his two strawmen or clarifying his notion of semantic paradigm, AK evades my argument regarding a simple fact of complexity theory by invoking “look, squirrels!” This fact his quite relevant to AK’s claim about a model of every interacting particle:

The size of the state space and game tree for chess were first estimated in Claude Shannon (1950). “Programming a Computer for Playing Chess”. Philosophical Magazine 41 (314). Shannon gave estimates of 10^43 and 10^120 respectively, smaller than the upper bound in the table, which is detailed in Shannon number.

http://en.wikipedia.org/wiki/Game_complexity

(In Hamming’s conference cited above, there’s an interesting anecdote about the chess playing style of Claude Shannon.)

Modelling the interaction of every single interacting particle may not be possible within the bounds of our multiverse. AK’s squirrel claim is therefore invalid, just like his first two strawmen.

But yeah, AK’s answer was TonyB’s seal of approval.

Comment on The albedo of Earth by and Then There's Psychics

0
0

…and Then There’s Physics | March 12, 2015 at 11:32 am |

“Water vapour is clearly an important greenhouse gas, but it’s not a persistant GHG. CO2 is a persistent GHG.”

Sorry, but that is simply wrong. You meant it is not a consistent GHG. It is quite persistent being present to some level everywhere.

Comment on The albedo of Earth by AK

0
0
<blockquote>Modelling the interaction of every single interacting particle may not be possible within the bounds of our multiverse.</blockquote>"Look! Another squirrel!" I never said it was possible. In fact, I was offering a <i>reductio ad absurdum</i>.

Comment on The albedo of Earth by Lucifer

0
0

It’s the IR not visible, so the high albedo low clouds are not well represented,
but it may be worth watching the clouds:

One way in which albedo does react to temperature is tropical thunderstorm activity.
Temperature increase of day – convective clouds increase.
Temperature decrease of night – convective clouds decrease.


Comment on The albedo of Earth by Danny Thomas

0
0

Capt.

From page 9:”The global cooling implies a reduction in the blackbody
longwave emission from the Earth’s surface. All the
simulations were integrated until quasi‐stable equilibrium
was reached, so the reduction in emitted longwave radiation
must be balanced by other radiative changes. These radiative
changes are largely from water vapor and cloud changes
(Table 1), which is consistent with the conclusions of
Barreiro et al. [2006] and Brierley et al. [2009]. However,
the increase in the meridional SST gradient results in a much
greater role of water vapor for the radiation balance.
Establishment of zonal SST gradients has a smaller impact
because the drying in the Southern Hemisphere is partially
compensated by the moistening associated with the intensification
of the (northern) Intertropical Convergence Zone
(ITCZ).

Comment on The albedo of Earth by swood1000

0
0

ATTP –
If there is no hemispherical energy balance that keeps the albedos of the two hemispheres the same then we have to say that they are the same just by chance, right? It would seem that if there is a hemispherical energy balance that keeps the albedos of the two hemispheres the same then to the extent that changes to albedo are resisted, changes in forcing that would result from albedo changes are also resisted. But can it even be said that such a mechanism would resist changes to albedo? Maybe it would just act to synchronize the NH if the SH changes.

Comment on The albedo of Earth by Steven Mosher

0
0

beth

“Re questions? In doing science, even climate science,
do we not ask questions, make conjectures, that is,
tentative theories, which we submit to critical discussion
‘n testin’ directed ter the elimination of error?…Jest askin’.

in science we ask questions, therefore all questions are good.
I don’t believe you are making that foolish argument.
In science people form hypothesis ( and many other things)
These may be constructed in the form of a question.
However, in science, we form our questions to nature and sometimes
she doesn’t answer. In science we ask our questions because we are interested in the answer. And if we don’t get an answer we don’t blame nature, for not doing our bidding. Yes, in science we ask questions.
From that fact NOTHING follows. Tony asked about the new computer.
And “wondered” whether it was worth the money. It should not surprise you
to find that elsewhere he had criticized the expenditure of money on computing. It should not surprise you that in general he objects to any form of explaining climate that doesn’t follow his historical approach.
rather than making an argument that the computer is not worthwhile, he shifts the burden with his question. That is not the way we ask questions or make arguments in science.

Comment on The albedo of Earth by Rud Istvan

0
0

C1ue, some GCM observations, since understanding the possible sources of model/observational discrepancy is an area I am presently actively researching. It would appear that for weather (and therefore by extension, climate behavior) purposes, 1.5 km grids suffice run out maybe a week. These need initial conditions, but those need not be ‘measured’ data. They are simply initial condition inputs, interpolated from larger observed ‘field’ conditions like an area’s windspeed and direction.
The finest CMIP5 grid resolution is about 1.1 degree lat/lon, or about 110 km at the equator. UCAR uses a rule of thumb that doubling resolution requires 10x computation ( the minimum woild be 4 times the number of XY cells times twice the time steps since these mipust correspondingly shrink.. 110-55-27-13-7-3-1.5 resolution would require 7 orders of magnitude more computational horsepower. Since these models already take 3 months or more to run out to 2100, a single GCM run at 1.5 km resolution on todays best supercomputers would need 2.5 million years. Computationally intractable.
So for the present finest possible grid, all sub grid scale processes have to be parameterized. These include key phenomena like convection cells cloud formation, and precipitation (which removes water vapor and lowers that feedback. And that is where the core discrepancies almost certainly lie. The parameterization is chosen to ‘best hindcast’ compared to observed stuff (e.g. Temp). Yet observed includes natural variation in addition to any GHG signal. The root issue is therefore the attribution assumptions built into any parameterization.
What could be done, but has not yet been, is to take something like the stadium wave history to correct the hindcast parameterization for a partly natural history, then see whether the pause is reproduced, or as in this thread a stable and hemispherically symmetric albedo results. I suspect this will not be done, since merely doing the exercise itself contradicts the ‘CO2 control knob’ meme and IPCC AR5′ attribution of the 1975-2000 warming to anthropogenic causes. Would by definition lower sensitivity, undercut the alarm, and obviate the proclaimed need for immediate action.

Comment on The albedo of Earth by Mi Cro

0
0

…and Then There’s Physics commented

Okay, I was trying to think if my wording could be pedantically criticised. I didn’t think hard enough :-) Yes, “limited” is more
appropriate than “set”.

And I accept “Limit” as what I was trying to describe.

As you say, the current view is that RH will remain roughly constant as we warm. This may not be true, or there may be well be things that add complexity, but I don’t think that there is anything in this paper that suggests some major flaw in this basic picture.

What i didn’t realize is that every night rel humidity goes way up, we get dew (or frost) on everything, as I already mentioned even with a -70F sky temp, the rate of surface temp cooling slows way down (to 10-20% of earlier cooling) when the rel humidity rises, if it’s sunny the next morning it all evaporates.
How much energy is released to space, when you condense 10-20 grams of water over a sq meter and freeze it with the temperature still falling, doesn’t that basically release a lot of latent heat into the air, and then to space? That’s a lot more than just cooling air, even more interesting is when I measure the IR temp of the concrete sidewalk and asphalt driveway after sunset, and late at night.

Kind of pertinent, I estimated the inland rain fall of one of the hurricanes that rained out over the midwest dropped ~1/3 the volume of Lake Erie on it’s path north. How much heat did that amount of water have to lose to condense?

Viewing all 147818 articles
Browse latest View live




Latest Images