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ChiRaven
http://www.physorg.com/news5619.html

Gee, THAT one takes me all the way back to third grade science class, where we were told that people floated better in salt water than in fresh water because salt water was "heavier" (denser) and could hold us up better.

If this comes as news to anybody, they must have slept through that lesson.
adoucette
Everybody seems to get on the Global Warming bandwagon.

QUOTE
Noerdlinger demonstrates that melt water from sea ice and floating ice shelves could add 2.6% more water to the ocean than the water displaced by the ice, or the equivalent of approximately 4 centimeters (1.57 inches) of sea-level rise.


What is UNSTATED is that miniscule increase would occur only if ALL floating ice shelves melted, which is not even in the most pessimistic of projections.

The reason that we ignore this 2.6% is because the sea level contribution from the anticipated amount of melting sea ice is relatively small, primarily because most of it is polar and most of it will remain, even with global warming.

The concern, of course is with the ice which is now on land, because virtually all net melting of that ice results in a rise in sea levels.

Arthur
a_ht
Antartica is a land mass above see level covered by 1-2 kilometer thick ice. Melted, the complete volume of that ice would be added to the sea level.
adoucette
True, but Antarctica is not melting, in fact overall its been getting a tad colder for the last several decades. As far as ocean levels go, Antarctica is a negative influence, more water ends there permanently than melts off. Of course precipitation levels are quite low in the interior, so the negative effect is fairly low.
Arthur
Janice
The ice cube is in concentrated salt water. It is not stated whether the salt water is equivalent to ocean water, so the corresponding scale is not necessarily accurate for comparing to the increase of ocean levels. Truth in advertising is good, especially in a scientific treatise.

Also, when sea water is freezing, it tends to push the minerals to the center of the ice, which freezes last. So ice formed from frozen sea water is fresh water, except for the center, which is quite saline. You can observe this in your freezer. If your water is not absolutely pure, there will be a slight cloudiness in the center of the ice cube, where the impurities have been pushed by the pure frozen water around them. So frozen sea water will sit much lower in the water than fresh frozen ice, because it is carrying the weight of the minerals with it.
aknute
QUOTE
You can observe this in your freezer. If your water is not absolutely pure, there will be a slight cloudiness in the center of the ice cube, where the impurities have been pushed by the pure frozen water around them.


Janice,
The cloudiness you talk about is not from the impurities in your water. They are stress cracks. When ice freezes, it does so from the outside in like you explained. When it gets to the center, the water needs to expand as it freezes and pushes against it's already frozen shell causing tiny stress cracks. Manufactured ice is always crystal clear because there are vibrating devices in the machines to relieve the tension. This would explain why icicles are clear but a frozen puddle is white. The icicle is constantly moving and freezing on top of itself, the puddle is confined.

-Art
StevenA
I think the fact that there hasn't been a significant rise in sea levels should be a big clue that there is no significant global warming either.

It's true that sea levels would rise some if ice was melting but there's been almost no rise in sea levels observed (I don't remember the exact estimate but it's something like a small fraction of an inch over decades and no cities are going to be flooded, despite what Al Gore says ... unless of course we blow money on stuff like this instead of maintaining a levy).

I also remember some claims that fresh water from glaciers could stop the gulfstream currents. This is simply impossible as these currents work via heat convection. No matter what the temperature or average density of the water is, waters warmed in the equator will rise toward the poles as colder waters sink and return toward the equator. It's the same principle as air rising above a heater and sinking to the floor elsewhere. If you had some smoke or otherwise change the density of the air in some area, it can't stop this heat exchange from occuring.

It's also claimed (or at least strongly implied) that CO2 is directly responsible for any rise in temperature over the last 100 years or so and that's simply not the case. This doesn't explain why the upper atmosphere is getting colder either or why Ice Ages occured.

If you instead look at water vapor and solar radiation, the picture becomes much clearer. When the atmosphere is colder, water vapor condenses out of the air. Water vapor in the atmosphere can vary hundreds of times more than CO2 and it is a much more significant contributor to any greenhouse effect we experience, yet you virtually never hear about this. Why the stealth mode propoganda if it's not for the exact same reason the U.S. is in the middle east to monopolize the energy industry?

Ice Ages were not caused by a lack of CO2. CO2 only exists as ~1/3000th of the atmosphere, whereas water vapor averages about 100 times as much and has a higher variability as well and can go from close to 0% in some areas, yet close to 5% of the atmosphere in other areas. Even if the average variability runs from 2-3%, compared to the worst case manmade assumptions for CO2 production, that's ~100 times the variability of CO2 and water vapor levels appear to have increased over time as well:

http://www.cmdl.noaa.gov/ozone.html

"Stratospheric Water Vapor

Utilizing balloon-borne frost-point hygrometers, GMD has detected an approximately 1% per year increase in stratospheric water vapor at Boulder, Colorado, since 1980. Besides implications for climate change, increased water vapor can affect the rate of chemical ozone loss, for example, by increasing the incidence of polar stratospheric clouds. Satellite measurements of water vapor, although not of adequate length for accurate trend determination, suggest that the increase may extend to other latitudes.


So if CO2 has increased by ~25% over the last 100 years and water vapor has increased by this percent over 25 years, then the absolute rates of growth between the two are:

(~1/3000*25%/100 years) = .00000083 parts per year for CO2
(~1/30*25%/25 years) = .00033 parts per year for H2O

So relative rates are .00033/.000000083 = 400 times as rapid a growth in absolute growth of water vapor compared to CO2!!!!!!!!!!

And even then we still don't see cities flooding!

So CO2 increases by ~25% over 100 years or so, yet water vapor, a much more significant greenhouse increases by ~25% in 25 years and we're suppose to say CO2 is responsible for this small fraction of an inch increase in water levels over time?

I can't believe the levels of hype surrounding this global warming campaign. Who's footing the bill for the propoganda?
Stephen Saines
I think the talk of freezing salt water rather misses the point!

The very first sentence of the article:
"When ice on land slides into the ocean".

Where exactly is "ice on land" salted?

I see a number of posts from a year ago. I'd say events have caught up with the cynics.
KateM
Steven A is incorrect about ocean circulation. The large-scale global circulation is based on thermohaline circulation in which cold, dense water in the north Atlantic sinks and begins the deepwater current that upwells in the North Pacific. The concern about the rise in temperature is the possibility that a "younger dryas" concept could occur in which the melted polar areas become a blanket of freshwater on the surface which then could affect the circulation and could keep the water from sinking.

Disregarding increased carbon as a source for the change in climate is irresponsible as well. The oceans are not able to absorb carbon at the accelerated rate in which we are producing it and the excess carbon in the air is trapping the heat within the atmosphere.
ChrisM
QUOTE (KateM+Dec 2 2006, 02:06 AM)
Disregarding increased carbon as a source for the change in climate is irresponsible as well. The oceans are not able to absorb carbon at the accelerated rate in which we are producing it and the excess carbon in the air is trapping the heat within the atmosphere.

Kate, could you please explain to what exactly you are referring when you label the opposing viewpoint as "irresponsible"? I'm not entirely sure what's irresponsible about observing current data and past data and concluding that the climate changes aren't scientifically conclusive about the source.

You go on to remark that "'the oceans' are not able to absorb 'carbon' at the accelerated rate in [sic] which we are producing it" then go on to make a completely unsupported scientific assertion that the CO2 is trapping "the heat" within the atmosphere.

Not only are the oceans far from our only source of carbon exchange, but there is no evidence supporting the idea that CO2 is the sole cause of climate or heat changes. Otherwise, if you want to make a Correlation Is Causation fallacy, don't let me interrupt.
Catastrophe
The salt water you used is much more concentrated than sea water.

Using the average density of sea water and assuming 10% floating ice I calculate an increase in sea level due to density difference as only a few inches.

Density of sea water = 1030 kg/m^3

That means that the melted fresh water (ice) would occupy about 3% greater volume than the salt water (less as the salt water is diluted). For same area, depth will be 3% greater.

The floating ice is tiny in comparison with the land ice. Even if it were 10% then the increase in sea level would be 0.3% of about 20 feet or about 0.6 feet or 7.2 in.

Zephir
wink.gif
Catastrophe
QUOTE
The floating ice is tiny in comparison with the land ice. Even if it were 10% then the increase in sea level would be 0.3% of about 20 feet or about 0.6 feet or 7.2 in.


Sorry. That should have been 3% of about 20 feet but the end result is still 7.2 in.


Good Elf
Hi All,

Short comment...

QUOTE (StevenA+)
I think the fact that there hasn't been a significant rise in sea levels should be a big clue that there is no significant global warming either.

It's true that sea levels would rise some if ice was melting but there's been almost no rise in sea levels observed (I don't remember the exact estimate but it's something like a small fraction of an inch over decades and no cities are going to be flooded, despite what Al Gore says ... unless of course we blow money on stuff like this instead of maintaining a levy).
What do we mean by "significant"? Maybe this will help show that it is really happening...
Global warming claims tropical island
It's not frontpage news on your papers but if you think this is all that will happen ... tongue.gif
Global Warming does not mean that everything is going to get "hotter", what is happening is weather extremes are going to increase and of course sea level will eventually rise. Not all of it may be due to human activity but in the end it is not a blame game it is what are we going to do about it as the number of world refugees increase and become part of a household near you? Particularly important is the early evacuation of some smaller inhabited islands in Vanuatu recently which are becoming very borderline...

I am sure this is nothing for any Westerners to worry about since they can just go somewhere else to live can't they?

As for Antarctica not melting but getting colder... better get them "Happy Feet" paddl'in real quick. I have also read that Rockhopper Penguin Rookeries have been suffering catastrophic declines in numbers as the habitats are changing too rapidly for them to cope... You might have to appreciate the animated version of these cute creatures more since the public will probably not be able to see the real ones (unless of course you visit your local Museum of Natural History). Its OK though... they all come to life at night... I saw Ben Stiller playing fetch with a T-Rex...
http://www.washingtonpost.com/wp-dyn/conte...6030201712.html
Big chunks of the southern oceanic ice sheet have broken off and floated free in the Southern Ocean... this is unprecedented! A large section of the Larsen B Ice Shelf the size of Wales broke off and floated free a couple of years ago... Believe me ... this is not a "seasonal event".
user posted image
One important "knock on" effect is the krill dieback since they all breed under the contenental icesheets. A lot of Krill died from that event and the habitat is now gone. Without them the loss of this really major foodsource in the oceans will be "very significant" and result in many a fishing fleet around the world even in warmer zones, pulling back into port without a catch in the very near future. It is a very complex set of equations... increased precipitation due to the higher atmospheric saturated vapor pressure in the short term... may lead to some strange climatic effects locally but don't worry the news is probably all bad.

Cheers
Catastrophe
QUOTE
Big chunks of the southern oceanic ice sheet have broken off and floated free in the Southern Ocean...


If it is floating the sea level increase will already have taken place (Archimedes Principle). There will be a tiny further increase in sea level due to the difference in density between fresh and salt water (SG 1.03). I calculate this as about 7 inches if all the floating ice melted. Melting of land based ice would total around 200 feet increase if all melted.
Catastrophe
adoucette

QUOTE
What is UNSTATED is that miniscule increase would occur only if ALL floating ice shelves melted, which is not even in the most pessimistic of projections.

The reason that we ignore this 2.6% ...


Do I take it you are stating that about 2.6% is floating and the rest on land.

In my calculation I used an (arbitrary) estimate of 10%. Using your figure (if I understand correctly) my 7.2 inches (if all floating ice melted) must be downed to about 1.9 inches only.

adoucette
QUOTE
Do I take it you are stating that about 2.6% is floating and the rest on land.


No.

See the original article.

http://www.physorg.com/news5619.html

Arthur
Catastrophe
Thank you for your reply.

QUOTE
In a paper titled "The Melting of Floating Ice will Raise the Ocean Level" submitted to Geophysical Journal International, Noerdlinger demonstrates that melt water from sea ice and floating ice shelves could add 2.6% more water to the ocean than the water displaced by the ice, or the equivalent of approximately 4 centimeters (1.57 inches) of sea-level rise.


So the figure would be approximately 2.6/102.6 x 100% or 2.53%

Still the 1.57 inches is not a million miles away from my 1.9 inches.

I am not clear, though, what he means. 2.6% more water to the ocean than the water displaced by the ice. Does this mean the water displaced by the ice from the land?

adoucette
No its about ALREADY floating ice.

The issue is that generally people have totally discounted any sea level impact from the melting of FLOATING ice because of the assumption that its IMPACT on ocean levels is already accounted for.

But they forget the Salinity issue and thus leave out the VERY SLIGHT impact if ALL the floating ice melts.

Arthur
MacTonight
QUOTE (aknute+Sep 7 2006, 04:20 PM)

Janice,
The cloudiness you talk about is not from the impurities in your water. They are stress cracks. When ice freezes, it does so from the outside in like you explained. When it gets to the center, the water needs to expand as it freezes and pushes against it's already frozen shell causing tiny stress cracks. Manufactured ice is always crystal clear because there are vibrating devices in the machines to relieve the tension. This would explain why icicles are clear but a frozen puddle is white. The icicle is constantly moving and freezing on top of itself, the puddle is confined.

-Art

Art, you're grossly misinformed about "crystal clear" ice manufacturing. There's no "vibration" process.

The water is purified using reverse osmosis, before it is frozen. This removes 99.8% of the impurities. This is the one and only reason the storebought ice is clear.
Catastrophe
QUOTE
But they forget the Salinity issue and thus leave out the VERY SLIGHT impact if ALL the floating ice melts.


Yes: VERY SLIGHT. Less than 2 inches.
AND that is if ALL the floating ice melts.

blink.gif

Contradictory Results
The experimenters in this case used a 26% NaCl solution. Average ocean salinity is about 35 ppt, or a 3.5% soln.

I did a kitchen experiment using a 3.5% soln of NaCl and ice cubes. I marked the meniscus at the addition of the ice cubes, then marked it after the ice had melted (I allowed the ice to melt at "room temperature...in my home, that was about 72F). Results? The level had actually decreased. Granted, this wasn't "laboratory controlled", but I strongly suspected that their results were due to the much heavier concentration of NaCl. In effect, the salinity of the ocean does not contribute greatly to added buoyancy, thus the greater volume of the ice more than offset the slight difference in density.
Catastrophe
Which just goes to prove that this global warming nonsense ... is just nonsense. AND that apparently some will post unreal conclusions to support unreal nonsense?

Why?
hawksecho
There are two benefits from the use of desalination of sea water in providing both fresh water and energy. We will face in this century, a very severe water shortage and the need for clean electrical power. The Chinese know this as better then any of us. With their approach to using massive coal power plants, they put a new coal burning power plant in place every six to twelve months. May God have mercy on the human soal...
Mircea the Romanian
QUOTE (hawksecho+Oct 2 2007, 01:13 AM)
The Chinese know this as better then any of us. With their approach to using massive coal power plants, they put a new coal burning power plant in place every six to twelve months.

It is more like every 6 DAYS.
yor_on
Antarctica not melting?

http://www.nasa.gov/vision/earth/lookingat...c-20070515.html
http://www.smh.com.au/news/National/Antarc...4597958236.html
http://www.cnn.com/2007/TECH/science/05/02/arctic.ice/
http://earthobservatory.nasa.gov/Newsroom/...7032324604.html

If you want to be so extremely accurate in your projections concerning possible salinity differences in the oceans you will have to look at every cubic inch of it as salinity differs even in the same body of water :) Ask any submariner worth his salt ::))

As for how Antarctica's land based ice may break down. It will most probably be the cause of the underground (ice) tunnels that flows and weaken the ice structures above, when that landbased Ice start to fracture and start gliding you're welcome to build a human chain stopping it, or maybe you would like to try? Atombombs, tablesalt, or some other type of human glue ::))

We humans are puny in the face of natural forces as lightning storms etc, we are used to small changes in our habitat, therefore we believe based on our memory that we are the masters of this planet, but i think Gaia begs to differ here :) Isn't it somewhat fatiguing to proclaim all studies as being made by frauds and freaks, awh sorry, Gorians :)
Roman Fyseek
Let's say that we eliminate the salt water for a moment.

I have pure water. Its SD is 1.000. Average density 1.000.
I also have a pure water ice cube. Its SD is 0.995 due to the crystalline structure. Average density 0.995.

So, I place my ice cube in water. It floats. Overall, let's say that the average density of the water plus the ice is 0.999. As the ice melts, it becomes more dense. Ignoring temperature, the water and ice becomes water at 1.000. So, it appears that the average density of the glass of water plus the ice-cube has increased. If density increases, volume decreases, right? (also known as ice has a larger volume than the original liquid water)

So, now I've got a glass of salt water. Its SD is 1.025. Average density of 1.025 (I know, I just said that)

I place my pure ice cube in the salt water. It floats. Overall, let's say that the average density of the water at 1.025 plus the ice cube at 0.995 has just become 1.024 (wild exaggeration). This is where I get stuck. As the ice melts, its density changes from 0.995 to 1.000, ignoring temperature still. So, the ice, once again, has increased in density. So, the 1.024 (the average density of the saltwater and the ice cube) will go up to, let's say 1.0245. It appears, to me anyway, that the average density has increased.

What am I missing? Once again, my numbers are wildly exaggerated. Average density does *not* imply uniform density.
Roman Fyseek
And, another way of thinking about the problem:

Let's say that we take an ocean and place a light boat completely filled with ice. The boat sinks a lot. Feel free to mark the level on the outside of the boat.

The boat and the ice displace some ocean (due to their weight, not volume).

Now melt the ice.

The ocean should not notice the difference. The water line marked on the boat above shouldn't change. The boat hasn't changed weight, nor has the freshly melted ice changed weight. However, if one were to look at the boat, one would find that the volume of the contents of the boat has decreased due to the higher density of the fresh water as compared to the fresh ice.

Where is this additional displacement?

I must be missing something obvious.
Roman Fyseek
I think I've found a thought experiment that fits noerdlinger's model.

Imagine a ziplock bag of freshwater.

Place the ziplock bag of freshwater into a tank of saltwater. The bag floats. Not only does it float, it floats and a little bit sticks out of the salt water. (I first considered a balloon, but that would give me a little mountain in the middle. I didn't want to have to think about pressure from the balloon).

Anyway, the freshwater ziplock floats and then some. It's that 'then some'. Regardless of the fact that the water shrinks when it melts, it doesn't shrink to the point where it would become neutrally buoyant. If one were to suddenly solidify everything at and below the surface of the saltwater, to include the interior of the bag below the surface of the saltwater and then slit the top of the bag, that skim of water is that 2.6% (or, the difference in density between the water at 1.000 and the salt water at 1.026 [my fish like it at 1.025]).

And, the question I now have is, assuming I've finally got it all straight in my mind, how was this ever missed in the past? Why would it take until 2005 to publish this?
Catastrophe
http://en.wikipedia.org/wiki/Buoyancy

Let's hope the ziplock bag has the same density as water.

Seriously, I don't see the problem.

Ice is "pure" water and floats on slightly salty sea water.

If ice had the same density as sea water there would be NO change in level when the ice melted.

Since ice has a slightly different density (about 2.6% different) then there will be a slight change in sea level. About small inches different if ALL the floating ice melted.

Don't forget that the Gulf Stream could change due to global warming causing northern latitudes to get colder. Less (no) ice melting and less (no) change in sea level. Colder in UK though.
Catastrophe
QUOTE
And, the question I now have is, assuming I've finally got it all straight in my mind, how was this ever missed in the past? Why would it take until 2005 to publish this?


I don't think it was missed. I believe most people thought it almost irrelevant. Until someone tried to squeeze some spin out of it.

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