Weatherlawyer wrote:

From
http://www.bbc.co.uk/sn/tvradio/prog..._summary.shtml

In the Andes mountains, climate researcher Dr Lonnie Thompson, of Ohio
State University, was gathering evidence of the region's climatic
history using ice cores drilled in glaciers.

Almost immediately Thompson and his team noticed something intriguing.
The historic records showed that over the last one hundred years, every
time the ice cores showed drought in the mountains, it corresponded to
a particular kind of wet weather on the coast, a weather system known
as an El Nino. In other words drought in the mountains meant an El Nino
on the coast. If Thompson could trace back the climate record in the
mountains he'd also get a picture of what happened on the coast.

The result was fascinating. The climate record suggested that at around
560 to 650 AD - the time the Moche were thought to have collapsed -
there had been a 30-year drought in the mountains, followed by 30 years
or so of heavy rain and snow.

I've just been watching a plausible story about the last ice age; a
recording from the Open University on the BBC's educational, night time
filler. There seems to be a massive fault in the interpretation in what
glaciers can and can't do. But I'm fuzzy on what that is exactly.
Pointless of me trying to take the argument apart without knowing at
leat something about glaciers.

The problem has a focus somewhere in the way that experts were
presenting facts: Look over here and we see evidence that the glacier
deposited this and that sort of thing. They never say how, because the
physics of such large ice sheets is still cutting edge physics.

So, one more cross post.

We know that ice is transparent to most forms of sunlight. And it would
appear that there is a tendency for it to become colder than diurnal
variations of insolation would allow mainly because of reflection and
refraction near the surface.

So that's why alpine glaciers can exist. They can even exist at lower
latitudes even where the ice is out near the regions where the
atmosphere is thin.

In fact for some reason the ice can last indefinitely in the Andes of
northern Peru.

All of Peru is in the tropics. Northern Peru reaches almost to the
Equator and the centre of Peru is some 10 degrees south. It gets most
of its sunlight at acute angles. Why are they so cold? Despite having
24/7 sunlight in summer, most people insist it is the angle of the sun
that keeps the polar ice extant.

Anyone got any links on the physics of ice? Mechanical stuff please not
religious or quasi religious scientific beliefs.