Re: Solar Activity Reaches 1,000 Year Peak

On 10/04/07 18:43, in article Xns990E7749F743Eneptune@xxxxxxxxxxxxxx,
"Earl" <neptune@xxxxxx> wrote:


And it is more complicated than you know.

This in turn affects high altitude nucleation which determines
cloud cover and size of droplets.

There is an excellent correlation between temperature and sun
spot count. We do not need much of an effect.

And still more complicated than that. But you are one of the few
on this newsgroup who is scientifically literate enough
to handle the following.

"Can Earth's Albedo and Surface Temperatures increase Together"
which can be downloaded on PDF if you google that title.

The authors are well known (Pallé, E., P. R. Goode, P. Montañés-
Rodriguez, and S. E. Koonin) and it is published in a peer reviewed
journal. Several of them are involved with the earthshine method of
estimating earth's albedo.

The article is complex since it deals with two types
of cloud formations (high and low). Figure 1 shows clearly cloud
formation dropping continually from around 1985 to 2000, passing
thorough several sun spot cycles without noticing them graphically
and then started up from 2000 to 2005. They deal with two different
levels of cloud formation and they differ during this period.

Although measurements have not yet gone on long enough to demonstrate
a purely cyclic behavior, the suggestion is there. From
2000 on cloud formations are up and the net "albedo" has
increased. The authors note that the increasing albedo
has not reversed global warming.

There is a difference between atmospheric and surface albedos, and
between short and long wavelength albedos, and high and lower level
cloud formations! So it is a conceptual mess for those who wish to
have one variable explain all (like sun spot variations)

What is clear is that that solar irradiance does not appear to be
changing in this entire picture. If fact, thinking about global
warming only in terms of solar irradiance variations is misleading.
Venus is a poster boy example of this. Since the planet is closer to
the sun it receives nearly twice the solar energy than the earth does,
but the energy flux at the surface is HALF that of earth's due to its
high albedo (65%) compared to the Earth (30%). This is due to Venus'
cloud cover. On the emitting side of the ledger, the greenhouse
heating effect is some 500°K, much more than earth's 35*. Mars,
without any major atmosphere only has a 6° greenhouse heating
effect.

Without a greenhouse effect, the temperature of Venus would be 20°C
cooler than on earth just because of its cloud albedo. So on Venus
the greenhouse effect is calling the tune. The earth's climate
is a more complex issue, and varies with geological time. No single
factor calls the tune on earth all of the time. Climate variations
seem mostly control by plate tectonics, the current cald period
(taking a multi-million year view) on earth is due to that, not sun
spot variations or CO2, or sun radiation changes. We just happen to be
in a period where man is effecting the climate, it will not last
long since man will not be on earth long (multi-million year time
scale). But viewed on the human lifetime scale, if we had not added
more CO2 to the atmosphere, and if it had remained nearly constant as
it has in the last several thousand years, other factors would have
played dominating roles and probably sent temperatures progressively
lower.

So you are correct, think about the cloud covers. But it
is more complicated than simply dealing with nucleation,
eventually the albedo issue has to enter.

I have more reference to comment on but this suffices for the moment.








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