Discussion > Force X
They've not yet finished explaining it, EM. I'm going to continue digesting it for a while.
michael hart
EM - Some of it is heavy going because (I think) they are explaining things to be understandable to people unfamiliar with concepts like frequency responses.
They note that:
- The input to the climate system (Sun's total radiance) has a peak in its frequency spectrum at around 1/11 cycles per year.
- The output from the climate system (global temperature) does not have such a peak in its frequency spectrum.
So the transfer function relating the output to the input (which is the ratio of their Fourier transforms) has a dip when its magnitude is plotted as a function of frequency, at around 1/11 cycles per year.
This seems a great coincidence - what physical effect in the Earth's system could just happen to have an anti-resonance at the frequency of the sunspot cycle?
Now they started talking about Force X as something modulating the Earth's albedo to answer this question.
At this point, I have put myself on hold.
Things that modulate things do so via nonlinear effects. The concept of a transfer function requires that the system be linear to be meaningful.
So some very careful thinking is needed - to understand what nonlinear effects are involved and whether or not linear system concepts can still be applied to understand what is going on. I imagine all will become clear in due course.
Martin A
What encourages me about this work by Jo and David is that somebody is making a serious attempt to carry out genuine research into what makes the earth's climate tick.
After the "professionals'" endless bouts of handwaving, ad hom attacks on those who disagree and wagon-circling defence of their pre-conceived ideas it is refreshing that someone is prepared to put time, effort and (presumably) some of their own money — since no-one is prepared to support anything that might challenge the current paradigm — into something that might prove ground-breaking.
Or might prove a dud, but then that is what science is about — allegedly!
Mike Jackson
It's complete nonsense and although I shouldn't be I'm a little surprised there are some who are taking it seriously.
There are many obvious criticisms but at a higher level if you use their approach any time you have measurement A that is cyclic, and posit/assume that it must effect measurement B which has no such cycle then you're going to have a notch delay filter at around the same cycle length and a factor X; and even then they still needed the nuclear tests fudge factor.
Keep going with this approach and every theorized cyclic cause A that shows no effect on B will have a notch delay filter and we will have an infinite number of Factor X's to explain nature.
redc
haha.
splitpin
redc
Have you taken the trouble to point out the errors on Jo Nova's site? It would be nice to think that someone who can see the flaws in this research is making a proper contribution towards either disproving it or improving it.
Or, like our friends in climate science, do you simply pontificate?
Serious question.
Mike Jackson
redc: I can see what you are saying. On the other hand, it would be very surprising indeed if the level of radiation from the Sun had no effect on Earth's temperature.
So the presence of the 'notch filter' seems to need more explanation than simply "the level of radiation from the sun has no effect on the Earth's temperature".
For all I know, the thermal mass of the oceans is perfectly adequate to explain why there is no significant fluctuation in the Earth's temperature at a frequency of 1/11 cycles per year. In that case, you'd have a lowpass filter rather than a bandstop filter. Would that be another instance of "it's hiding in the ocean"?
Martin A
I don't see the point of posting on their site as I can see how other valid criticisms have been treated. Additionally until the spreadsheet is released none of us know what they've actually done.
redc
David Evans has effectively correlated a signal of 11 year period with noise (the temperature data) and found, as everyone else has, that there is no correlation. He concludes from this that the earth is filtering out 11 year signals and characterises the earth response as a notch using this single data point. But he hasn't tried a 5 or 15 year signal (or any other period) because obviously he cannot - the sun has only the eleven year period. One data point is not enough to say that this notch exists. He's then spent a year and half and written huge Excel (say what?) model based on this false premise. He seems like a guy who is so obsessed with the idea of Anything But Carbon (ABC) that he has lost sight of common sense. Or maybe he is just taking the piss.
Raff
The model is now available at jonova .
Entropic man
EM - on the "where there is harmony" thread you said
Expansion coefficient is 1.39*10^-3/C.
Jul 10, 2014 at 1:53 PM | Unregistered CommenterEntropic man
Could you please check and give a reference for the expansion coefficient of seawater you used. I know it varies significantly depending on temperature and pressure but the values I found seem to be very different from the value you quoted (unless I made some sort of mistake copying the numbers).
I am guessing you assumed some sort of average value to deal with varying temperatures and pressures. Is that correct?
Martin A
I used the expansion coefficient for fresh water from here .
I read the table, but was not sure which combination of pressure, temperature and salinity would be most appropriate, so I defaulted to the simplest. It would have overestimated the expansion somewhat.
Remember it was just a back of the envelope calculation. :-)
Entropic man
EM - on the "where there is harmony" thread you said
Expansion coefficient is 1.39*10^-3/C.
EM - "Remember it was just a back of the envelope calculation. "
Thanks. I could not make sense of it because the coefficient of expansion I found (for seawater) was about an order of magnitude less than the value you quoted (eg I found 3.25E-4 (at pressure = 100 MN m−2, 20°C) and still less at lower temperatures and pressures).
So, assuming everything else in your calculation is correct, (I have not had the opportunity to verify yet) this would lead to sea level rise of twenty two centimetres per century - far less alarming than your scary 2.2m per century.
Following your link, I found:
The amount of heat in gram calories per second which is conducted through a surface of area 1 cm2 is proportional to the change in temperature per centimeter along a line normal to that surface, and the coefficient of proportionality, κ, is called the coefficient of thermal conductivity (dQ/dt = −γ dϑ/dn). For pure water at 15°C the coefficient is equal to 1.39 ×10−3
Is it fair to assume that your scary result came from using the coefficient of thermal conductivity by mistake where the expansion coefficient should have been used?
Martin A
Here's the link again
Martin A
Martin A
Oops! Me a culpa. :-\
Entropic man
EM - thanks for the reply. Don't let it stop you posting stuff.
Martin A
Martin A
Let's try that again.
The volume of the oceans is 1.35*10^9 cubic kilometres.
Specific heat capacity is 4.18 *10^3J/kg/C
Expansion coefficient is 1.6 × 10^-4/C.
Imbalance, a conservative 10^22J/yr.
For the whole ocean specific heat is 5.64 ×10^24J/C. Id all the imbalance went into the ocean it would warm the entire volume by 1C in 564 years.
This would produce an expansion of 2.16 ×10^5 cubic kilometres. At 3.6 ×10^2 per mm the total rise would be 6 × 10^2mm overall, 1.06 mm/year.
That looks a lot closer to observation. Thermal expansion is reckoned to produce about half of the current sea level rise of 3.2mm/year, which would give an imbalance of at least 1.69 × 10^22J/year.
Its not an exciting rate of sea level rise alone. Unfortunately the feedback effect of this temperature rise on ice melt may be of more concern.
Entropic man
Thanks EM, I'll take a look at the numbers later.
Unfortunately the feedback effect of this temperature rise on ice melt may be of more concern.
I'd say it's one of those things that simply can't be answered with present knowledge but not the sort of thing to loose sleep over.
If the sea in polar regions warms a tiny bit, will that melt any ice other than what is already floating on the sea? Dunno but sounds unlikely to me.
If the sea in tropical regions warms up a bit, is that going to melt any ice? Sounds extremely unlikely to me.
Martin A
Martin A
"If the sea in polar regions warms a tiny bit, will that melt any ice other than what is already floating on the sea? Dunno but sounds unlikely to me."
That small change is enough to move the ice edge away from much of the Greenland coast, allowing warm air onto the ice sheet. Don't expect a linear response to temperature in this environment.
Entropic man
I think we can forget about Force X . Jo nova and David Evans have acknowledged that the notch was an artefact of their technique.
Entropic man
I have been reading Jo Nova and David Evans' recent posts .
They use a computer model to predict that temperatures will drop by 0.6C by 2020 . They infer the effect of changes in a mysterious forcing from the Sun. This is about as strong as the greenhouse effect and operates with an 11 year time lag, referred to as the notch.
I found their explanation rather vague and confusing , perhaps someone here could clarify their thinking.
I applaud one thing, they make a clear short term prediction about temperature changes over the next few years, easily falsified.