Re: [asa] A simple example

From: William Hamilton <willeugenehamilton@gmail.com>
Date: Fri Dec 18 2009 - 09:39:15 EST

Thanks, Rich.

I will respond at greater length later -- you've touched on an issue that is
discussed in Scafetta and West's papers, but I haven't looked at that for a
while. I need to find the reference and reread it. The short answer is that
the earth-sun system is a high order, nonlinear, chaotic system. Such
systems demonstrate sensitive dependence on initial conditions, as well as
superposition of oscillations at many different frequencies. See

http://www.scholarpedia.org/article/Stochastic_resonance

C. Nicolis, Solar variability and stochastic effects on climate, Sol. Phys.
74, 473-478 (1981).

C. Nicolis, Stochastic aspects of climatic transitions-response to a
periodic forcing, Tellus 34, 1-9 (1982).

It would also probably be useful if you haven't viewed it already, to view
the video of Scafetta's talk at EPA last February. There's a link to it in
my original message.

On Thu, Dec 17, 2009 at 10:22 AM, Rich Blinne <rich.blinne@gmail.com> wrote:

> Even though resonance is theoretically possible before you go there you
> need to answer the question of why wasn't there resonance for thousands of
> years and suddenly in the mid-20th Century things just changed? Be10 proxy
> studies have shown that solar irradiance AND the climate have responded in
> sync with sunspots. The problem is that AGW has swamped this effect.
> Prior to the mid-20th Century knowing the solar irradiance from Be10 and
> when there were volcanic eruptions the proxy record can be explained by
> mostly these two effects using computer model hindcasts. Furthermore, the
> forcing was not resonant. It's was direct with a relatively short delay. In
> short, you didn't need to model any resonance to explain the climate prior
> to the Industrial Era. After the mid-20th Century there was a large
> divergence, though, and the climate could not be explained by these natural
> forces alone.
>
> The last few years the Sun has given us an excellent controlled experiment.
> We have been stuck for several years with almost no sunspots and as late as
> this year it looked like we might have a repeat Maunder Minimum. Thus, there
> was good reason to believe that this would have a relative cooling effect on
> the climate. So we have AGW and the Sun running against each other and we
> can then see without the need of relying on computer models which is the
> larger effect. The results of this "experiment"? The current decade is on
> average 0.18 degrees C warmer than the 90s.
>
> Rich Blinne
> Member ASA
>
> On Thu, Dec 17, 2009 at 8:38 AM, William Hamilton <
> willeugenehamilton@gmail.com> wrote:
>
>> I have browsed through references supplied by Rich and Randy, and I will
>> read them in more detail in the next few days. However, let me state a
>> suspicion I have had for some time: I'm not convinced anyone (in the
>> conventional climate change community) is considering the potential of
>> resonance to cause temperature swings to grow with time -- even with very
>> small excitation. I have put together a simple example using Mathematica,
>> and the results are posted on my blog: bricolagia.blogspot.com. It's
>> probably the simplest possible example, and I claim no resemblance to the
>> earth/sun dynamics. However, it does demonstrate that with an excitation
>> varying by 0.1 percent of the base value, there is no limit to the size of
>> the response that can be realized. Although it's very crude (the efforts of
>> a novice at Mathematica) I will gladly email my Mathematica file to anyone
>> who asks.
>>
>> Let me take this opportunity to add my voice to Glenn's: We need a forum
>> in which we can post charts and graphs.
>>
>> --
>> William E (Bill) Hamilton Jr., Ph.D.
>> Member American Scientific Affiliation
>> Austin, TX
>> 248 821 8156
>>
>>
>

-- 
William E (Bill) Hamilton Jr., Ph.D.
Member American Scientific Affiliation
Austin, TX
248 821 8156
To unsubscribe, send a message to majordomo@calvin.edu with
"unsubscribe asa" (no quotes) as the body of the message.
Received on Fri Dec 18 09:39:50 2009

This archive was generated by hypermail 2.1.8 : Fri Dec 18 2009 - 09:39:50 EST