| Topic: |
Science > Physics |
| User: |
"habshi" |
| Date: |
15 Jan 2005 03:09:43 PM |
| Object: |
Global dimming masking greenhouse effect |
Excellent program with full transcript at the site below.
For the last thirty years particulate pollution has reflected sunlight
back into space , cutting solar energy reaching the surface by 20% or
so , but now in the North we are cleaning up the act , its starting to
rise steeply and there were 10,000 deaths in France two years ago.
Interestingly evaporation depends not on temp but on the
energy of solar photons hitting water and kicking molecules off the
surface and there has been a 20% fall in that .
The program predicts that temps will rise by 2C by 2030 ,
starting the melting of Greenland ice sheets flooding most cities . By
2050 it will be 4C and set fire to the Amazon forests and by 2100 it
will be 10C , and set free the methane hydrates 10,000 billion tonnes
setting off a monumental greenhous effect , with temp higher than it
has been for 4 billion years ! Maybe towards Venus like.
Maybe we have to rush into nuke and geothermal energy and
start tapping supervolcanoes like Yellowstone with a vengence.
http://www.bbc.co.uk/sn/tvradio/programmes/horizon/dimming_trans.shtml
NARRATOR (JACK FORTUNE): This is a film that demands action. It
reveals that we may have grossly underestimated the speed at which our
climate is changing. At its heart is a deadly new phenomenon. One that
until very recently scientists refused to believe even existed. But it
may already have led to the starvation of millions. Tonight Horizon
examines for the first time the power of what scientists are calling
Global Dimming.
NARRATOR: September 12th 2001, the aftermath of tragedy. While America
mourned, the weather all over the country was unusually fine. Eight
hundred miles west of New York, in Madison, Wisconsin a climate
scientist called David Travis was on his way to work.
DR DAVID TRAVIS (University of Wisconsin, Whitewater): Around the
twelfth, later on in the day, when I was driving to work, and I
noticed how bright blue and clear the sky was. And at first I didn't
think about it, then I realised the sky was unusually clear.
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| User: "" |
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| Title: Re: Global dimming masking greenhouse effect |
15 Jan 2005 03:38:15 PM |
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In sci.physics habshi, part time saviour of humanity and full time
idiot <habshi@anony.com> babbled:
Excellent program with full transcript at the site below.
Sounds like a real winner to me...
For the last thirty years particulate pollution has reflected sunlight
back into space , cutting solar energy reaching the surface by 20% or
so , but now in the North we are cleaning up the act , its starting to
rise steeply and there were 10,000 deaths in France two years ago.
Ergo we must have more fossile fueled cars belching exhaust to put back
the particulate pollution. Problem solved.
Interestingly evaporation depends not on temp but on the
energy of solar photons hitting water and kicking molecules off the
surface and there has been a 20% fall in that .
Utter babble.
The major factor in evaporation is the local humidity.
Increasing the temperature and/or moving air drops the local humidity
and increases the evaporation rate.
The program predicts that temps will rise by 2C by 2030 ,
starting the melting of Greenland ice sheets flooding most cities . By
2050 it will be 4C and set fire to the Amazon forests and by 2100 it
4 degrees C doesn't set fire to trees, idiot.
<rest snipped>
--
Jim Pennino
Remove -spam-sux to reply.
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| User: "Franz Heymann" |
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| Title: Re: Global dimming masking greenhouse effect |
16 Jan 2005 04:24:51 AM |
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<jimp@specsol-spam-sux.com> wrote in message
news:csc2g7$80j$1@mail.specsol.com...
In sci.physics habshi, part time saviour of humanity and full time
idiot <habshi@anony.com> babbled:
Excellent program with full transcript at the site below.
Sounds like a real winner to me...
For the last thirty years particulate pollution has reflected
sunlight
back into space , cutting solar energy reaching the surface by 20%
or
so , but now in the North we are cleaning up the act , its
starting to
rise steeply and there were 10,000 deaths in France two years ago.
Ergo we must have more fossile fueled cars belching exhaust to put
back
the particulate pollution. Problem solved.
Interestingly evaporation depends not on temp but on the
energy of solar photons hitting water and kicking molecules off
the
surface and there has been a 20% fall in that .
Utter babble.
The major factor in evaporation is the local humidity.
No. Roderick did the calculation. You did not. You are therefore
not empowered to waffle about it.
An individual photon absorbed by an individual molecule might well
give it sufficient kinetic energy to allow it to escape from the
surface before thermal equilibrium conditions under which evaporation
in the dark has been re-established
Increasing the temperature and/or moving air drops the local
humidity
and increases the evaporation rate.
The program predicts that temps will rise by 2C by 2030 ,
starting the melting of Greenland ice sheets flooding most cities
.. By
2050 it will be 4C and set fire to the Amazon forests and by 2100
it
4 degrees C doesn't set fire to trees, idiot.
No, idiot, but it generates conditiond favourable to forest fires.
Before shooting off your mouth next time, stir up your neurons.
Franz
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| User: "Edward Green" |
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| Title: Re: Global dimming masking greenhouse effect |
18 Jan 2005 03:35:04 AM |
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Franz Heymann wrote:
<jimp@specsol-spam-sux.com> wrote in message
news:csc2g7$80j$1@mail.specsol.com...
The major factor in evaporation is the local humidity.
No. Roderick did the calculation. You did not. You are therefore
not empowered to waffle about it.
An individual photon absorbed by an individual molecule might well
give it sufficient kinetic energy to allow it to escape from the
surface before thermal equilibrium conditions under which evaporation
in the dark has been re-established
Oh. That's what Roderick showed. I thought later you saying he had
done work on the spontaneous combustion of wood. Sorry.
As for the former point, Jim Pennino can, and does, continue to waffle
by in effect allowing that this is a factor, but not the major factor.
The language "major factor" or "the major factor" is vague enough so it
may be that no truth value can be assigned to this claim either way,
but "totally swamped" sounds more hopeful, sugguesting we wonder
whether variation in solar irradiance is a significant factor in
evaporation rates compared to variation in temperature and humidity.
There are cooperative effects: in still air extra molecules kicked into
the layer of humid air directly over the water may be more likely to be
immediately reabsorbed rather than diffusing away, whereas with
efficient wind mixing any process which enhances the rate of transfer
out of the surface will directly add to transfer rate out of the fluid.
I see no reason a priori why switching on sunlight may not
signficiantly increase evaporation: a possibility not to be ruled out
by the persistance of evaporation in the dark. Of course water can
evaporate in the dark! Jeez. Straw dog city in this thread: lack of
combustion of wood in 45C kiln rules out spontaneous combustion of
large sample of untreated whole trees and deadwood cooked in sun at
same air temperature (so we are told), evaporation of water in the dark
rules out higher rate of evaporation given illumination (so we are
asked to believe).
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| User: "habshi" |
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| Title: Re: Global dimming masking greenhouse effect |
25 Jan 2005 06:07:19 AM |
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More fascinating facts from Bill Bryson's book
The physics of fossilization are such that only one species in 120,000 of the estimated 30b that
have existed on earth gets fossilized ie sinks in mud to be crushed by overlying sediment etc.
This means that there might have been millions of species of large dinos, mammals which have no
fossil records and we may never know about them
Of the 270m Americans living today , only 50 bones or three quarters of a skeleton will get
fossilized , the rest will crumble into dust !
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| User: "habshi" |
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| Title: Re: Global dimming masking greenhouse effect |
25 Jan 2005 04:04:08 PM |
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Earth had 35% Oxygen 100m years ago compared to 21% today and
so land animals grew very large. Even millipedes were 2 meters long !
We need to get the oxygen levels back up so we can be big too .
If you stretch out your hands to represent 4b years or the age
of the earth , then the tip from fingertips to the other wrist would
represent the amount of time when life was just microscopic single
celles . One hand contains all complex life - plants and animals . A
finger nail represents the time mammals have been here , and the tip
of the fingernail , about 1mm the time humans have been on earth.
In the sea are creatures which feed on methane . Maybe we can
stop the danger of methane hydrates by transporting them there.
A solar flare releases the energy of a billion hydrogen bombs
and can wipe us out as the earth cant protect us from that many high
energy solar particles .
All the more reason to build a colony of the moon , and one on
the far side too ,
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| User: "" |
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| Title: Re: Global dimming masking greenhouse effect |
25 Jan 2005 04:15:12 PM |
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In sci.physics habshi <habshi@anony.com> wrote:
Earth had 35% Oxygen 100m years ago compared to 21% today and
so land animals grew very large. Even millipedes were 2 meters long !
We need to get the oxygen levels back up so we can be big too .
Idiot.
<snip remaining babble>
--
Jim Pennino
Remove -spam-sux to reply.
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| User: "" |
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| Title: Re: Global dimming masking greenhouse effect |
25 Jan 2005 08:43:48 AM |
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In sci.physics habshi <habshi@anony.net> wrote:
More fascinating facts from Bill Bryson's book
And what has this to do with physics or any of the soc groups you've posted
to?
<snip>
--
Jim Pennino
Remove -spam-sux to reply.
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| User: "habshi" |
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| Title: Re: Global dimming masking greenhouse effect |
25 Jan 2005 11:20:20 AM |
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Note it said the physical processes which cause fossilization. If you are not interested in
my threads just put an ignore sign on them . Sometimes the subject does veer off the topic a bit ,
but I am trying to keep down the number of threads so as not to cause annoyance.
Another item of interest in the book is that the body is composed of ten quadrillion microscopic
cells but we carry 100 quadrillion bugs on it !! ie we are more bacteria than human .ie
100,000,000,000,000,000 !
There are copepods in the ocean which are so numerous that they turn the ocean black
for miles but only a single fossil except one in an ancient fish stomach has ever been found !
These bugs should be able to use the oxygen and get rid of excess co2 BUT the ocean lacks iron and
so we need to add , maybe through slow diffusing bags.
Last time somebody tried it , the ocean became like a thick soup . We could multiply the
fish take many fold by adding iron regularly to our oceans and use the greenhouse effect to our
good.
...
Search for life signal on Titan
Titan: An atmosphere not unlike Earth's billions of years ago
Enlarge Image
Scientists will comb data sent back from Titan by the Huygens probe for the chemical signature of
life in a bid to identify the moon's source of methane.
Methane is constantly destroyed by UV light so there must be a source within Titan to replenish the
atmosphere.
Life is a possible - though some think unlikely - source of this hydrocarbon along with geological
processes.
The surface is too cold for biology, but microbes could survive in an ocean within Titan, a senior
scientist says.
Methane can also be released from a trapped form called clathrate and produced by a geological
process called "serpentinisation". Neither of these involve biology.
Dominated by nitrogen, methane and other organic (carbon-based) molecules, Titan is thought to
resemble a deep-frozen version of Earth 4.6 billion years ago.
Liquid methane rains down on Titan into river channels carved between hills of water ice. Reservoirs
of this hydrocarbon probably lie on or just below the surface.
But UV light would destroy all the methane on Titan within 10 million years if it were not being
constantly renewed.
We have liquid water, organics not so far away; we have everything on Titan to make life
Francois Raulin, University of Paris
"We cannot say there is absolutely no chance for life," Dr Francois Raulin, one of three
interdisciplinary scientists on the Huygens mission told the BBC News website.
"There is no chance for life on the surface because it is too cold and there is no liquid water.
"However, models of Titan's interior show there should be an ocean about 100km deep at around 300km
below the surface."
If the models are correct, this ocean would be composed mostly of liquid water with about 15%
ammonia at a temperature of about -80C, said Dr Raulin.
"We have liquid water, organics not so far away; we have everything on Titan to make life," he
explained.
Work in progress
If methane-producing microbes had colonised this habitable zone, scientists might detect its
chemical signature by looking at the relationship of two forms (or isotopes) of the element carbon -
C12 and C13.
Living cells preferentially incorporate C12. So compounds produced by living things should be
depleted of "heavier" isotopes such as C13; they are said to have a high C12/C13 ratio.
Some process is renewing Titan's supply of methane
Scientists should be able to measure this ratio in data sent back by the Gas Chromatograph Mass
Spectrometer (GCMS) instrument on Huygens.
"The GCMS can directly detect the C12/C13 carbon ratio. We haven't done that yet, but we're working
on it," said Sushil Atreya, a professor of planetary science at the University of Michigan, US, and
a GCMS team member.
"It's one factor we can take into account to figure out how methane is getting replenished."
However, Professor Atreya favours the geological process of serpentinisation as a more likely source
of the Saturnian moon's methane.
In serpentinisation, geothermal activity generates methane through the oxidation of metals such as
iron, chromium and magnesium which could be contained in crustal rocks below Titan's surface.
Another possibility is that methane molecules are trapped in a water-ice matrix called clathrate (or
methane hydrate).
Dr Raulin also considers these geological processes as viable sources of methane on Titan.
On 14 January, the spacecraft plunged through the moon's atmosphere, sending scientific data -
including stunning images - back to ground controllers.
It landed on Titan at around 1138 GMT at a leisurely speed of around 5m/s and transmitted a signal
until at least 1555 GMT.
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| User: "" |
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| Title: Re: Global dimming masking greenhouse effect |
25 Jan 2005 11:20:26 AM |
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In sci.physics habshi <habshi@anony.net> wrote:
Note it said the physical processes which cause fossilization. If you are not interested in
Post it to sci.archaeology, idiot.
<trash deleted>
--
Jim Pennino
Remove -spam-sux to reply.
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| User: "habshi" |
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| Title: Re: Global dimming masking greenhouse effect |
18 Jan 2005 08:59:55 AM |
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The program said that the rate of pan water evaporation has fallen in the last 30 odd years
, a surprise since temps have gone up , and the reason is less sunny days due to global dimming.
Also the cloud belts are shifting south , increasing the Sahara and in the future the monsoons may
shift south as well
He3 on our moon can be mined for fusion reactors
excerpts
bbc
NARRATOR: So Liepert and Stanhill's work was widely dismissed. But Global Dimming was not the only
phenomenon that didn't seem to fit with Global Warming. In Australia two more biologists, Michael
Roderick and Graham Farquhar were intrigued by another paradoxical result - the world-wide decline
in something called the pan evaporation rate.
PROF GRAHAM FARQUHAR (Australian National University): It's called pan evaporation rate because it's
evaporation rate from a pan. Every day all over the world people come out in the morning and see how
much water they've got to add to a pan to bring it back to the level it was the same time the
morning before. It's that simple.
http://www.mindfully.org/Air/2002/Decreased-Pan-Evaporation1nov02.htm
The cause of decreased pan evaporation over the last 50 Years
RODERICK & FARQUHAR / Science v.298, 1nov02
Cooperative Research Centre for Greenhouse Accounting, Research School of Biological Sciences,
Institute of Advanced Studies, Australian National University, Canberra ACT 0200, Australia.
*To whom correspondence should be sent. E-mail:
--------------------------------------------------------------------------------
It is now well established that the surface of Earth has, on average, warmed ~0.15°C decade-1 over
the past 50 years (1). One expected consequence of this warming is that the air near the surface
should be drier, which should result in an increase in the rate of evaporation from terrestrial open
water bodies. However, despite the observed increases in average temperature, observations from the
Northern Hemisphere show that the rate of evaporation from open pans of water has been steadily
decreasing over the past 50 years (2). This trend is general (3, 4) but not universal (5). The
contrast between expectation and observation is called the pan evaporation paradox. It is important
to understand why pan evaporation has decreased despite the increases in average temperature in
order to make more robust predictions about future changes in the hydrological cycle.
Two proposals for the decline in pan evaporation have been advanced: the first invokes changes in
the humidity regime over the pans (6), whereas the second invokes reductions in solar irradiance
resulting from more clouds and/or aerosols (5, 7) and is generally consistent with the independent
suggestion that increased pollution would weaken the hydrological cycle (8). The first proposal is
that pan evaporation has decreased because evaporation from the environment surrounding the pan has
increased (6). The explanation is that in water-limited
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| User: "Steve Schulin" |
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| Title: Re: Global dimming masking greenhouse effect |
18 Jan 2005 10:09:28 AM |
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In article <41ed2457.1358253@news.clara.net>, (habshi)
wrote, in part:
The program said that the rate of pan water evaporation has fallen in the
last 30 odd years
, a surprise since temps have gone up , and the reason is less sunny days due
to global dimming...
After noting the dimming and pan evaporation findings, Dai et al [J.
Hydrometeorology 5:1117, Dec 2004] discuss how and why evaporation can
increase, and probably has increased, even though pan evapoation has
decreased:
"Pan evaporation (Epa) and actual evapotranspiration (E), however,
exhibit complementary rather than proportional behavior such that, for
regions with less than adequate moisture, E increases with potential
evapotranspiration (consistent with the Palmer model) but decreases with
Epa (Brutsaert and Parlange 1998). For example, over the Mississippi
River basin during the last 50 yr, increased cloudiness has decreased
solar heating and thus pan evaporation, while actual evapotranspiration
has increased because of increased precipitation and soil moisture
(Milly and Dunne 2001). A recent reassessment of the evaporation data
from the United States and the former Soviet Union (Golubev et al. 2001)
suggests increasing trends in actual evaporation over southern Russia
and most of the United States during the last 40 yr."
"Our PDSI results, which are based on atmospheric moisture supply and
demand near the surface, are consistent with increased evaporation under
greenhouse gas-induced warming, as predicted by comprehensive coupled
climate models (Cubasch et al. 2001; Dai et al. 2001). Global
temperature increases have become pronounced after the 1970s (Folland et
al. 2001) and have been attributed to human-induced climate changes
arising primarily from increased greenhosue gases (Mitchell et al. 2001;
Dai et al. 2001; Karl and Trenberth 2003). Higher temperatures increase
the water-holding capacity of the atmosphere and thus increase potential
evapotranspiration. Hence global warming not only raises temperatures,
but also enhances drying near the surface, as is captured by the PDSI.
The increased risk of drought duration, severity, and extent is a direct
consequence (Trenberth et al. 2003), and the theoretical expectations
are being realized, as shown here and discussed by Nicholls (2004)."
Here are the citations for the references in this section:
(Brutsaert and Parlange 1998) - Brutsaert, W., and M. B. Parlange, 1998:
Hydrologic cycle explains the evaporation paradox. Nature, 396, 30.
(Milly and Dunne 2001) - Milly, P. C. D., and K. A. Dunne, 2001: Trends
in evaporation and surface cooling in the Mississippi River basin.
Geophys. Res. Lett., 28, 12191222.
(Golubev et al. 2001) - Golubev, V. S., and Coauthors, 2001: Evaporation
changes over the contiguous United States and the former USSR: A
reassessment. Geophys. Res. Lett., 28, 26652668.
(Cubasch et al. 2001) - Cubasch, U., and Coauthors, 2001: Projections of
future climate change. Climate Change 2001: The Scientific Basis: The
IPCC WG1 Third Assessment Report, J. T. Houghton et al., Eds., Cambridge
University Press, 525582.
(Dai et al. 2001) - Dai, A. G., T. M. L. Wigley, B. A. Boville, J. T.
Kiehl, and L. E. Buja, 2001: Climates of the twentieth and twenty-first
centuries simulated by the NCAR Climate System Model. J. Climate, 14,
485519.
(Folland et al. 2001) - Folland, C. K., and Coauthors, 2001: Observed
climate variability and change. Climate Change 2001: The Scientific
Basis, J. T. Houghton et al., Eds., Cambridge University Press, 99181.
(Mitchell et al. 2001) - Mitchell, J. F. B., and Coauthors, 2001:
Detection of climate change and attribution of causes. Climate Change
2001: The Scientific Basis, J. T. Houghton et al., Eds., Cambridge
University Press, 695738.
(Karl and Trenberth 2003) - Karl, T. R. and K. E. Trenberth, 2003:
Modern global climate change. Science, 302, 17191723.
(Trenberth et al. 2003) - Trenberth, K. E., A. Dai, R. M. Rasmussen, and
D. B. Parsons, 2003: The changing character of precipitation. Bull.
Amer. Meteor. Soc., 84, 12051217.
(Nicholls 2004) - Nicholls, N., 2004: The changing nature of Australian
droughts. Climatic Change, 63, 323336.
--- END OF EXCERPT FROM DAI ET AL ---
The full citation for Dai et al (2004) is:
Aiguo Dai, Kevin E. Trenberth, and Taotao Qian. A Global Dataset of
Palmer Drought Severity Index for 18702002: Relationship with Soil
Moisture and Effects of Surface Warming. Journal of Hydrometeorology
5:1117-1130, December 2004.
The affiliation listed for all three authors is NCAR-Boulder.
I don't pretend to know the truth of the matter. I have long been
concerned with the results of any endeavor where Dr. Trenberth has a
guiding hand, but that doesn't mean he's wrong on this specific point.
[Have you guys and gals seen the stunning open letter released yesterday
which highlights Dr. Trenberth's recent mischaracterizations as seen by
a leader of the hurricane research community? It's available at
http://sciencepolicy.colorado.edu/prometheus/archives/science_policy_gene
ral/000318chris_landsea_leaves.html
and is discussed in sci.environment thread titled "IPCC process
'motivated by pre-conceived agendas' and 'scientifically unsound', sez
veteran IPCC author".]
Very truly,
Steve Schulin
http://www.nuclear.com
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| User: "" |
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| Title: Re: Global dimming masking greenhouse effect |
18 Jan 2005 09:35:02 AM |
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In sci.physics habshi <habshi@anony.net> wrote:
<snip>
He3 on our moon can be mined for fusion reactors
There is no such thing as a working, man made, fusion reactor.
<rest snipped>
--
Jim Pennino
Remove -spam-sux to reply.
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| User: "Edward Green" |
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| Title: Re: Global dimming masking greenhouse effect |
18 Jan 2005 08:37:31 PM |
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habshi wrote:
The program said that the rate of pan water evaporation has fallen in
the last 30 odd years
, a surprise since temps have gone up , and the reason is less sunny
days due to global dimming.
What is the operational definition of "pan water evaporation"?
NARRATOR: So Liepert and Stanhill's work was widely dismissed. But
Global Dimming was not the only
phenomenon that didn't seem to fit with Global Warming. In Australia
two more biologists, Michael
Roderick and Graham Farquhar were intrigued by another paradoxical
result - the world-wide decline
in something called the pan evaporation rate.
PROF GRAHAM FARQUHAR (Australian National University): It's called
pan evaporation rate because it's
evaporation rate from a pan. Every day all over the world people come
out in the morning and see how
much water they've got to add to a pan to bring it back to the level
it was the same time the
morning before. It's that simple.
http://www.mindfully.org/Air/2002/Decreased-Pan-Evaporation1nov02.htm
The cause of decreased pan evaporation over the last 50 Years
RODERICK & FARQUHAR / Science v.298, 1nov02
Cooperative Research Centre for Greenhouse Accounting, Research
School of Biological Sciences,
Institute of Advanced Studies, Australian National University,
Canberra ACT 0200, Australia.
*To whom correspondence should be sent. E-mail:
farquhar@rsbs.anu.edu.au
---------------------------------------------------------------------------=
-----
It is now well established that the surface of Earth has, on average,
warmed ~0.15=B0C decade-1 over
the past 50 years (1). One expected consequence of this warming is
that the air near the surface
should be drier, which should result in an increase in the rate of
evaporation from terrestrial open
water bodies. However, despite the observed increases in average
temperature, observations from the
Northern Hemisphere show that the rate of evaporation from open pans
of water has been steadily
decreasing over the past 50 years (2). This trend is general (3, 4)
but not universal (5). The
contrast between expectation and observation is called the pan
evaporation paradox. It is important
to understand why pan evaporation has decreased despite the increases
in average temperature in
order to make more robust predictions about future changes in the
hydrological cycle.
Two proposals for the decline in pan evaporation have been advanced:
the first invokes changes in
the humidity regime over the pans (6), whereas the second invokes
reductions in solar irradiance
resulting from more clouds and/or aerosols (5, 7) and is generally
consistent with the independent
suggestion that increased pollution would weaken the hydrological
cycle (8).
The first proposal is
that pan evaporation has decreased because evaporation from the
environment surrounding the pan has
increased (6). The explanation is that in water-limited
OK. I've got it!
Pan evaporation rate is off because the net effect of all variation in
the locality of the pans, including but not limited to humidity, wind
speed, temperature and solar irradiance, has resulted in a lower
reported net evaporation rate, averaged over all pans. I think that
covers it. ;-)
Too bad all the people at all those pans didn't have a few extra pieces
of equipment to measure all these local variables.
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| User: "" |
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| Title: Re: Global dimming masking greenhouse effect |
18 Jan 2005 10:28:42 AM |
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In sci.physics Edward Green <spamspamspam3@netzero.com> wrote:
Franz Heymann wrote:
<jimp@specsol-spam-sux.com> wrote in message
news:csc2g7$80j$1@mail.specsol.com...
The major factor in evaporation is the local humidity.
No. Roderick did the calculation. You did not. You are therefore
not empowered to waffle about it.
An individual photon absorbed by an individual molecule might well
give it sufficient kinetic energy to allow it to escape from the
surface before thermal equilibrium conditions under which evaporation
in the dark has been re-established
Oh. That's what Roderick showed. I thought later you saying he had
done work on the spontaneous combustion of wood. Sorry.
As for the former point, Jim Pennino can, and does, continue to waffle
by in effect allowing that this is a factor, but not the major factor.
The language "major factor" or "the major factor" is vague enough so it
may be that no truth value can be assigned to this claim either way,
but "totally swamped" sounds more hopeful, sugguesting we wonder
whether variation in solar irradiance is a significant factor in
evaporation rates compared to variation in temperature and humidity.
There are cooperative effects: in still air extra molecules kicked into
the layer of humid air directly over the water may be more likely to be
immediately reabsorbed rather than diffusing away, whereas with
efficient wind mixing any process which enhances the rate of transfer
out of the surface will directly add to transfer rate out of the fluid.
I see no reason a priori why switching on sunlight may not
signficiantly increase evaporation: a possibility not to be ruled out
by the persistance of evaporation in the dark. Of course water can
evaporate in the dark! Jeez. Straw dog city in this thread: lack of
combustion of wood in 45C kiln rules out spontaneous combustion of
large sample of untreated whole trees and deadwood cooked in sun at
same air temperature (so we are told), evaporation of water in the dark
rules out higher rate of evaporation given illumination (so we are
asked to believe).
Waffle?
OK, how's this?
The dominant factors in water evaporation is the local humidity and
water temperature.
Local humidty is a function of the air temperature and air movement which
replaces the local high humidity air with lower humidity air.
Any photon effects, other than heating, if they do in fact exist, are at
best trivial in comparison.
Get two clear, plastic, 2 liter soda bottles.
Cut the bottom off one such that you are left with a saucer.
Put equal amounts of water in both of them and put them side by side
in the noon day sun. Having an Englishman to watch is optional, but
noting the temperature of the water is mandatory.
Note the time required for each to go dry.
Unscrew your oven light and get the oven to the noon day temperature of
the water and repeat with the bottles in the oven.
For extra credit, repeat having the water at different initial temperatures.
--
Jim Pennino
Remove -spam-sux to reply.
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| User: "Edward Green" |
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| Title: Re: Global dimming masking greenhouse effect |
18 Jan 2005 09:35:41 PM |
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wrote:
Waffle?
Sorry. Overly harsh. Perhaps "light crispy wafer". :-)
OK, how's this?
<see previous post for details>
Experiment? Whoa. Heavy!
I have a few problems with your proposal: for one thing, I don't see
how we are to control for variations in relative humidity and air speed
in the oven vs. outside; for another, it will be difficult to regulate
the temperature of a household oven that finely; and for yet another,
I'm not sure I see the point of including the semi-closed bottle: yes,
trapping of air and increased humidity over the water will slow
evaporation, and I'd then expect net evaporation to be rate-limited by
diffusion or mixing at the bottle mouth. In other words, I'm fairly
sure you are right a priori about the insigificance of illumination in
this case (and while removing the over light was a nice touch, I
wouldn't expect that little bulb to do jack).
Ok.
Let me make a counter-proposal which seems to me to answer my own
objections: I take two 2L soda bottles, cut the bottoms off to make
two identical saucers, and set them outside in the noonday sun. One,
however, I cover with a sun screen at a height of about 1 foot, on four
slender sticks.
Now, it seems to me, we've automatically controlled for equality of
temperature, humidity and wind conditions: well, ideally the object
casting the shadow on saucer two might be even farther away in case it
modifies wind patterns. Or we could have two identical canopies, one
clear, the other reflective... but now we've failed to control for
heating of the blocked sunlight! We want to isolate the
photoevaporative effect alleged.
You know, this is actually somewhat ticklish...
Also, I've thought of a simple consistency check: If N moles of water
are directly "photoevaporated", then this would still require
absorption of N times the molar heat of evaporation directly by light
absorption at the surface. I don't know ... water looks kind of
transparent to me. And the adsorption had better be right at the
surface, not a um down, or that kicked molecule is going to thermally
equilibrate before it escapes so we're back to simple heating. Is
water more strongly absorptive in wavelengths other than the visual and
the interface? UV?
You know what? I think this rules the proposed effect out. To the
extent classical electrodynamics is adequate to describe the passage of
light between two different media, there is, AFAIK, surface reflectance
and transmittance, and bulk absorbance, but no specific "surface
absorbance": we don't deposite energy at the interface. Since
classical electrodyamics is known to be adequate to treatement of
interfaces (?), I deduce that any special photoevaporative effect must
be insignicant.
Satisfied?
There are however intermediate kinds of effects possible: say some
wavelength range is absorbed strongly in the first few mm or even cm of
water, not right at the interface. Now that looks like simple heating,
but it might be again that the surface temperature of the water is
higher than ambient under these conditions: e.g., if a thermometer in
air reads 30C 1 m about the surface in the dark, and also in the
sunlight, it might be that the surface temperature of water is really
30C in the latter case. That looks like "photoevaporation", but is
really a more macroscopic non-equilibration. There are also the
possibility of confounding variables galor: the air may simply be more
active, on average, at given local average temperature and humidity, in
brighter light.
Hmm... I beginning to tend to the idea that the effect Franz mentions
is real, but maybe mainly of academic significance, whereas there may
be many other effects related to the level of irradiation which are
really mediated by the local water temperature and air temperature and
relative humidity at the surface layer, but which may be confounded
with a true photoevaporative effect, since we can't measure these
mesoscopic variables.
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| User: "" |
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| Title: Re: Global dimming masking greenhouse effect |
18 Jan 2005 09:59:19 PM |
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In sci.physics Edward Green <spamspamspam3@netzero.com> wrote:
jimp@specsol-spam-sux.com wrote:
Waffle?
Sorry. Overly harsh. Perhaps "light crispy wafer". :-)
OK, how's this?
<see previous post for details>
Experiment? Whoa. Heavy!
I have a few problems with your proposal: for one thing, I don't see
how we are to control for variations in relative humidity and air speed
in the oven vs. outside; for another, it will be difficult to regulate
the temperature of a household oven that finely; and for yet another,
I'm not sure I see the point of including the semi-closed bottle: yes,
trapping of air and increased humidity over the water will slow
evaporation, and I'd then expect net evaporation to be rate-limited by
diffusion or mixing at the bottle mouth. In other words, I'm fairly
sure you are right a priori about the insigificance of illumination in
this case (and while removing the over light was a nice touch, I
wouldn't expect that little bulb to do jack).
The more I thought about it, the more problems I came up with.
The semi-closed bottle was for mitigating wind effects, and you probably
can't get an oven that close.
So, I was in the garage looking for pieces for a household repair and
noticed some copper stock I've been saving.
Take a 5/16 X 4 X 5 inch slab of copper and spot mill a 3/4 depression
in each end (all dimensions inches).
Take a 4 X 5 file card and cut two 1" holes centered on the milled
depressions.
Glue some toothpicks to the copper slab and glue the cardboard to the
toothpicks to form an insulating cover to prevent sunlight from heating
the copper slab.
Put equal amounts of water in each depression, shade one side, and time
the evaporation.
The copper slab should keep both samples equal in temperature.
Instrument with a Radio Shack thermometer/hygrometer and create curves
for varying temperatures and humidities.
--
Jim Pennino
Remove -spam-sux to reply.
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| User: "Edward Green" |
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| Title: Re: Global dimming masking greenhouse effect |
19 Jan 2005 08:45:46 PM |
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wrote:
The more I thought about it, the more problems I came up with.
<...>
The more I think about it, the more I become convinced that the claim
"solar irradiance increases evaporation rate under otherwise fixed
conditions" is true, but not because of photoejection of individual
molecules. It's true because solar irradiance of the liquid surface
will preferentially deposit energy near the surface, raising the
temperature of same relative to a fixed nominal system temperature.
In other words, I am accepting your claim that evaporation rate is only
significantly directly affected by local values of the standard
thermodynamic variables at the surface (temperature, composition,
pressure) and insignificantly affected by the illumination, but
claiming that illumination may significantly increase surface
temperature relative to a dark system, for a fixed temperature at a
given stand-off from the surface, and hence have significant indirect
effects on the evaporation rate.
So everybody is at least a little right, tra-lu-la-ray.
Your original design may have been improved by, instead of monitoring
direct evaporation from the saucers, monitoring the quantity of water
lapped from the saucers by both shaded and unshaded dogs in the noonday
sun, as watched by English observers.
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| User: "" |
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| Title: Re: Global dimming masking greenhouse effect |
19 Jan 2005 08:54:14 PM |
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In sci.physics Edward Green <spamspamspam3@netzero.com> wrote:
jimp@specsol-spam-sux.com wrote:
The more I thought about it, the more problems I came up with.
<...>
The more I think about it, the more I become convinced that the claim
"solar irradiance increases evaporation rate under otherwise fixed
conditions" is true, but not because of photoejection of individual
molecules. It's true because solar irradiance of the liquid surface
will preferentially deposit energy near the surface, raising the
temperature of same relative to a fixed nominal system temperature.
You don't get grant funding for statements like "when the sun is bright,
it is hotter and water evaporates faster when it is warm".
Reminds of years ago when the Section Head called me into his office to
give me a huge research report written by another section to evaluate.
He almost lost it when I told him the only point of the whole thing was
the plot of y=mx+b is a straight line...
<rest snipped>
--
Jim Pennino
Remove -spam-sux to reply.
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| User: "Dan Bloomquist" |
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| Title: Re: Global dimming masking greenhouse effect |
19 Jan 2005 09:08:14 PM |
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wrote:
In sci.physics Edward Green <spamspamspam3@netzero.com> wrote:
wrote:
The more I thought about it, the more problems I came up with.
<...>
The more I think about it, the more I become convinced that the claim
"solar irradiance increases evaporation rate under otherwise fixed
conditions" is true, but not because of photoejection of individual
molecules. It's true because solar irradiance of the liquid surface
will preferentially deposit energy near the surface, raising the
temperature of same relative to a fixed nominal system temperature.
You don't get grant funding for statements like "when the sun is bright,
it is hotter and water evaporates faster when it is warm".
Reminds of years ago when the Section Head called me into his office to
give me a huge research report written by another section to evaluate.
He almost lost it when I told him the only point of the whole thing was
the plot of y=mx+b is a straight line...
At the least, you guys are willing to do the science, (should I say, 'at
the most'?) There is a thread on related groups, 'But There Ain't No
Global Warming'. It seems that a fiction called "State of Fear" is the
definitive truth...
Some seem to think that NOAA data is a farce. Is it? Science should be
immune to human nature if properly applied...
Best, Dan.
P.S. I've added the four other groups. In spite of the litter it will
attract, the issue is well worth addressing. Plonk them if it is too much...
--
http://lakeweb.net
http://ReserveAnalyst.com
No EXTRA stuff for email.
What can you see if you can't see it all...
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| User: "Retief" |
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| Title: Re: Global dimming masking greenhouse effect |
23 Jan 2005 10:48:49 AM |
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Dan Bloomquist <EXTRApublic21@lakeweb.com> wrote:
Some seem to think that NOAA data is a farce. Is it? Science should be
immune to human nature if properly applied...
The NOAA/NCDC data is what it is... The data doesn't lie (too much),
but the people using the data are a different matter...
BTW, if I were to take the NCDC data at face value, I would discover
that the station in Traverse City, MI, didn't see rain for about a
year (in the 1961-1990 collection, at about 1990)...
And let these researchers not forget to examine carefully the records
and logs of EVERY STATION, before drawing conclusions based on those
data. Changes in station personnel, reading times, changes in station
location, and the reported instrument bias (net positive) all come
into play:
http://www1.ncdc.noaa.gov/pub/data/ushcn/daily/README
Retief
--
Use no 'z's (at all) to reply -- I hate spammers
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| User: "" |
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| Title: Re: Global dimming masking greenhouse effect |
19 Jan 2005 10:15:36 PM |
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Dan Bloomquist wrote:
jimp@specsol-spam-sux.com wrote:
In sci.physics Edward Green <spamspamspam3@netzero.com> wrote:
jimp@specsol-spam-sux.com wrote:
The more I thought about it, the more problems I came up with.
<economy snip>
Some seem to think that NOAA data is a farce. Is it? Science should
be
immune to human nature if properly applied...
Best, Dan.
P.S. I've added the four other groups. In spite of the litter it will
attract, the issue is well worth addressing. Plonk them if it is too
much...
Nice work Mr. B.
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| User: "" |
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| Title: Re: Global dimming masking greenhouse effect |
21 Jan 2005 03:02:52 AM |
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wrote:
\
In sci.physics Edward Green <spamspamspam3@netzero.com> wrote:
wrote:
The more I thought about it, the more problems I came up with.
<...>
The more I think about it, the more I become convinced that the
claim
"solar irradiance increases evaporation rate under otherwise fixed
conditions" is true, but not because of photoejection of individual
molecules. It's true because solar irradiance of the liquid
surface
will preferentially deposit energy near the surface, raising the
temperature of same relative to a fixed nominal system temperature.
You don't get grant funding for statements like "when the sun is
bright,
it is hotter and water evaporates faster when it is warm".
Well, I hope my analysis is at least a _little_ more sophisticated than
that. I was suggesting that for not spectacularly unreasonable
operational definitions of "hotter", one might observe that an
irradiated open system had a higher evaporation rate than a similar
unirradiated open system, even when both were nominally the same
temperature. One would be overreaching however in requiring some
special quantum mechanism for this though: it's comprehensible in terms
of where energy is being injected into the systems.
Your copper plate experiment was elegant, BTW, but it exceeds the
capabilities of my junk-around-the-house lab. ;-)
.
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| User: "" |
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| Title: Re: Global dimming masking greenhouse effect |
16 Jan 2005 10:07:39 AM |
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In sci.physics Franz Heymann <notfranz.heymann@btopenworld.com> wrote:
<jimp@specsol-spam-sux.com> wrote in message
news:csc2g7$80j$1@mail.specsol.com...
<snip>
The major factor in evaporation is the local humidity.
No. Roderick did the calculation. You did not. You are therefore
not empowered to waffle about it.
An individual photon absorbed by an individual molecule might well
give it sufficient kinetic energy to allow it to escape from the
surface before thermal equilibrium conditions under which evaporation
in the dark has been re-established
The point was any such effect in an open body of water on the surface
of the Earth would be totally swamped out by atmospheric effects of
humidity and wind.
Increasing the temperature and/or moving air drops the local
humidity
and increases the evaporation rate.
4 degrees C doesn't set fire to trees, idiot.
No, idiot, but it generates conditiond favourable to forest fires.
Before shooting off your mouth next time, stir up your neurons.
Habshi believes, and has stated such several times, that "warming"
will cause spontaneous combustion of trees.
Forest fires in warm weather are almost allways started by people, not
"nature", BTW.
--
Jim Pennino
Remove -spam-sux to reply.
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| User: "habshi" |
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| Title: Re: Global dimming masking greenhouse effect |
18 Jan 2005 03:48:40 PM |
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Remember trees are living things and have to keep their temps
within limits . At 45C or higher they may not have enough water to do
so , and photosynthesis may stop as enzymes stop working . Trees will
shrivel and die and be prone to fires .
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| User: "" |
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| Title: Re: Global dimming masking greenhouse effect |
18 Jan 2005 03:57:03 PM |
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In sci.physics habshi <habshi@anony.com> wrote:
Remember trees are living things and have to keep their temps
within limits . At 45C or higher they may not have enough water to do
so , and photosynthesis may stop as enzymes stop working . Trees will
shrivel and die and be prone to fires .
If the areas that are now 40C get to 45C, all that means is Canada can
grow more wheat.
--
Jim Pennino
Remove -spam-sux to reply.
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| User: "Franz Heymann" |
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| Title: Re: Global dimming masking greenhouse effect |
19 Jan 2005 11:46:16 AM |
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<jimp@specsol-spam-sux.com> wrote in message
news:csk0nf$7ae$1@mail.specsol.com...
In sci.physics habshi <habshi@anony.com> wrote:
Remember trees are living things and have to keep their
temps
within limits . At 45C or higher they may not have enough water to
do
so , and photosynthesis may stop as enzymes stop working . Trees
will
shrivel and die and be prone to fires .
If the areas that are now 40C get to 45C, all that means is Canada
can
grow more wheat.
No. It means a lot more than that.
Franz
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| User: "Eric Gisin" |
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| Title: Re: Global dimming masking greenhouse effect |
18 Jan 2005 05:01:57 PM |
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<jimp@specsol-spam-sux.com> wrote in message
news:csk0nf$7ae$1@mail.specsol.com...
In sci.physics habshi <habshi@anony.com> wrote:
Remember trees are living things and have to keep their temps
within limits . At 45C or higher they may not have enough water to do
so , and photosynthesis may stop as enzymes stop working . Trees will
shrivel and die and be prone to fires .
We had 100s km2 of forest fire in 2003. Drought and highs in 30s for months.
That didn't cause fires, but it made putting them out impossible. Drought
didn't kill any trees, fire and beetles did.
If the areas that are now 40C get to 45C, all that means is Canada can
grow more wheat.
Nope. We already grow wheat as far north as rich soil exists. Once it was grown
above the arctic circle on a river delta.
Global warming does not create more soil.
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| User: "" |
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| Title: Re: Global dimming masking greenhouse effect |
18 Jan 2005 08:00:32 PM |
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In sci.physics Eric Gisin <ericgisin@hotmail.com> wrote:
<jimp@specsol-spam-sux.com> wrote in message
news:csk0nf$7ae$1@mail.specsol.com...
In sci.physics habshi <habshi@anony.com> wrote:
Remember trees are living things and have to keep their temps
within limits . At 45C or higher they may not have enough water to do
so , and photosynthesis may stop as enzymes stop working . Trees will
shrivel and die and be prone to fires .
We had 100s km2 of forest fire in 2003. Drought and highs in 30s for months.
That didn't cause fires, but it made putting them out impossible. Drought
didn't kill any trees, fire and beetles did.
If the areas that are now 40C get to 45C, all that means is Canada can
grow more wheat.
Nope. We already grow wheat as far north as rich soil exists. Once it was grown
above the arctic circle on a river delta.
Global warming does not create more soil.
Nope, but it pushes the 90 day frost free line north.
Enough global warming and England may become a wine producing region again
like it was in Roman times.
--
Jim Pennino
Remove -spam-sux to reply.
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| User: "Franz Heymann" |
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| Title: Re: Global dimming masking greenhouse effect |
19 Jan 2005 11:46:17 AM |
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<jimp@specsol-spam-sux.com> wrote in message
news:cskf00$hgf$3@mail.specsol.com...
In sci.physics Eric Gisin <ericgisin@hotmail.com> wrote:
<jimp@specsol-spam-sux.com> wrote in message
news:csk0nf$7ae$1@mail.specsol.com...
In sci.physics habshi <habshi@anony.com> wrote:
Remember trees are living things and have to keep
their temps
within limits . At 45C or higher they may not have enough
water to do
so , and photosynthesis may stop as enzymes stop working .
Trees will
shrivel and die and be prone to fires .
We had 100s km2 of forest fire in 2003. Drought and highs in 30s
for months.
That didn't cause fires, but it made putting them out impossible.
Drought
didn't kill any trees, fire and beetles did.
If the areas that are now 40C get to 45C, all that means is
Canada can
grow more wheat.
Nope. We already grow wheat as far north as rich soil exists. Once
it was grown
above the arctic circle on a river delta.
Global warming does not create more soil.
Nope, but it pushes the 90 day frost free line north.
Enough global warming and England may become a wine producing region
again
like it was in Roman times.
It is. Now. It keeps winning international prizes at blind tastings
for its white wines. But production is only on a relatively small
scale.
Franz
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| User: "" |
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| Title: Re: Global dimming masking greenhouse effect |
20 Jan 2005 11:39:42 AM |
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In sci.physics Franz Heymann <notfranz.heymann@btopenworld.com> wrote:
<jimp@specsol-spam-sux.com> wrote in message
news:cskf00$hgf$3@mail.specsol.com...
<snip>
Nope, but it pushes the 90 day frost free line north.
Enough global warming and England may become a wine producing region
again
like it was in Roman times.
It is. Now. It keeps winning international prizes at blind tastings
for its white wines. But production is only on a relatively small
scale.
Franz
Bah, white wine is for girls and sissys; Romans wouldn't drink that.
--
Jim Pennino
Remove -spam-sux to reply.
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