Kirk Gordon wrote:
wrote:
Kirk Gordon wrote:
Cliff wrote:
On Sat, 24 Sep 2005 13:25:35 -0400, Kirk Gordon
wrote:
Since about 8,000 BC, the world's oceans have gotten warmer by about
35 degrees Fahrenheit.
I rather doubt it.
Look it up, Cliff.
How about if you tell us where you looked it up?
In truth, I didn't look it up. At least not recently What I wrote
was just a summary perspective based on reading and sources too numerous
to remember. But, for the fun of it, here are some web articles that
might help anyone interested:
http://muller.lbl.gov/pages/IceAgeBo...f_climate.html
http://www-das.uwyo.edu/~geerts/cwx/...hap15/lgm.html
http://www.ncdc.noaa.gov/paleo/abrupt/story_paleo.html
10,000 years ago was the beginning of the end of
the current ice age. Glaciation as far south as the Ohio River valley,
and substantial non-contiguous ice fields far south of that. Oceans in
total MUCH smaller than now, because of all the water containted in
glaciers. And average ocean temps 30 to 40 degrees F lower than at present.
Just what is the 'average ocean temperature' today?
Unless it is greater than 67 F, or the average includes ice, I
daresay it was not EVER 30 - 40 degrees F cooler than today.
According to NOAA, it's about 17C, or 62.6F, and ranges from -2C
(28.4F) at high latitudes to over 36C (96.8) in very warm spots, like
the Persian Gulf.
There is a reason why it is around 28.4 degrees F at high
latitudes, see below.
If that average does includes ice the latent heat, is also
a very important consideration, right?
I don't know what latent heat you're talking about.
Here is an explanation of latent heat of fusion:
http://en.wikipedia.org/wiki/Latent_heat_of_fusion
I'm just
discussing general water temperatures. And no, the numbers I mentioned,
and those I've quoted above, don't include ice.
OK.
You may be assuming that liquid water can't ever get below 0 degrees
C, or 32 degrees F. Those numbers only work for pure water. Ocean
water, filled with electrolitic salts, can get much, MUCH colder than
those numbers, and remain liquid. At this moment, somewhere near
Iceland, there's liquid water flowing around at several degrees BELOW
what we normally think of as the freezing point.
About three and one-half degrees F below the freezing point of pure
water.
My earlier statement wasn't politicallly motivated. I was just
making an observation that seems to be very well grounded in serious
science, and in mountains of (literally) rock-solid evidence.
I don't know if the evidence is solid but water at 32 F IS.
Think about the anti-freeze you put in your car's cooling system. A
bit of methanol or ethylene glycol added to ordinary tap water can
reduce the freezing point to 30 or 40 (or more) degrees Fahrenheit below
normal freezing temperatures. Oceans salts have exactly the same
effect, which is why ocean water doesn't freeze even when freshwater is
solid as rock at the same temperature. The polar ice caps, all
glaciers, and even ice-bergs floating in the ocean, are made of fresh water.
I am familiar with the concept of freezing point suppression.
Regarding the Arctic ice cap being freshwater, that is partly
because when seawater freezes the salts are mostly 'excreted'
(for want of a better term) from the ice. Some of the Arctic
ice cap is freshwater because it is formed by precipitation
on top of the sea ice.
Based on the following information it would appear that today the
freezing point of seawater is around 28.4 degrees F.
http://en.wikipedia.org/wiki/Freezing-point_depression
http://en.wikipedia.org/wiki/Sea_water
http://www.newton.dep.anl.gov/askasc...9/gen99263.htm
http://www.csgnetwork.com/h2ofreezecalc.html
Interestingly, when glaciers expand, and when they hold a larger and
larger percentage of the Earth's total water, the freezing temps of the
oceans would likely get even lower. That's because the volume of salts
in the oceans doesn't change much, even though the water volume does.
If the same salts are disolved in less water, the salt concentration
goes up, and freezing temps are reduced to even more extreme values -
WAY below 32F.
If the salinity were twice what it is today then the freezing
point would be about 25 degrees F. That does not agree well
with the assertion that the average ocean temperature was
30 to 40 degrees cooler ten thousand years ago, or ever.
--
FF