|
Post by mrsonde on May 26, 2013 6:03:04 GMT 1
And oh look, what the devil can all this ignorant arrogant nonsense be? Obviously, the fool who wrote this has never read a physics textbook! Or if he has, not the one you read! You should go and edit this balderdash immediately, alan. You're a scientist, right? en.wikipedia.org/wiki/Current_sea_level_riseSea levels around the world are rising... Between 1870 and 2004, global average sea levels rose 195 mm (7.7 in).[4] From 1950 to 2009, measurements show an average annual rise in sea level of 1.7 ± 0.3 mm per year, with satellite data showing a rise of 3.3 ± 0.4 mm per year from 1993 to 2009,[5] a faster rate of increase than previously estimated.[6] It is unclear whether the increased rate reflects an increase in the underlying long-term trend.[7] Two main factors contributed to observed sea level rise.[8] The first is thermal expansion: as ocean water warms, it expands.[9] The second is from the contribution of land-based ice due to increased melting. The major store of water on land is found in glaciers and ice sheets... Various factors affect the volume or mass of the ocean, leading to long-term changes in eustatic sea level. The two primary influences are temperature (because the density of water depends on temperature), and the mass of water locked up on land and sea as fresh water in rivers, lakes, glaciers, polar ice caps, and sea ice... Ice shelves float on the surface of the sea and, if they melt, to a first order they do not change sea level. Likewise, shrinkage/expansion of the northern polar ice cap which is composed of floating pack ice do not significantly affect sea level. Because ice shelf water is fresh, however, melting would cause a very small increase in sea levels, so small that it is generally neglected.
|
|
|
Post by buckleymanor1 on May 26, 2013 10:36:39 GMT 1
Typical answer what was expected! Your blatent willfull ignorance is in cherry picking the results to enforce your prejudice. Look at the table again from -30 to 4 degrees water contracts as it gets warmer, it gets denser reaching maximum density at around 4 degrees. I have allready explained this more than once.
|
|
|
Post by fascinating on May 26, 2013 21:50:24 GMT 1
I know that water gets more dense when cooled below 4C, but I don't see how that would lead to decrease in sea level. The water released from ice melt would circulate around the globe, most of it becoming warmer than 4C, it will become less dense (expand) and cause a small increase in sea levels.
|
|
|
Post by buckleymanor1 on May 26, 2013 23:00:00 GMT 1
I know that water gets more dense when cooled below 4C, but I don't see how that would lead to decrease in sea level. The water released from ice melt would circulate around the globe, most of it becoming warmer than 4C, it will become less dense (expand) and cause a small increase in sea levels. At around 4C it's more dense. Either side of 4C it becomes less dense.Eventualy the water released from the ice melt would circulate around the globe.Initialy though there would be a small decrease in sea levells followed by a small increase if the temperature continued to rise. Overall temperature rise or fall is pretty gradual.I am not sure of the exact figure for the rise in temperature over the last fifty years if there is one. So for arguments sake lets say it's 1/2 degree C. If temperature eventualy rises to allow an ice melt it would still take time for the water to circulate and in the meantime water around the poles would be maintained at 4C.
|
|
|
Post by fascinating on May 27, 2013 6:59:34 GMT 1
If the Arctic ocean was land-locked, separated from the world's oceans, then the melting of sea ice and introduction of melt water would, theoretically, lead to a tiny drop in the level of the water there. As it is connected with the oceans, any drop would surely be overwhelmed by water flowing in from elsewhere, which would happen very quickly. I suppose that might mean a theoretical, and immeasureably miniscule , drop in world sea level - but the mixing would quickly lead to most of the melt water becoming a lot warmer than 4C, leading to thermal expansion. So I can't agree that the loss of Arctic sea ice would lead to a drop in world sea level. This link shows that the sea level in the past 2 decades has gone up, largely as a result of melt of land ice www.bbc.co.uk/news/science-environment-20543483
|
|
|
Post by buckleymanor1 on May 27, 2013 10:06:27 GMT 1
It's gradual though.The melt water around the artic won't suddenly become a lot warmer temperature rises and falls as a gradient.The ice has to go from -30C to 4C and that will not happen overnight. The net effect will be a supply of more water at around 4C than there is at present if temperature rises. You are right that the supply of warmer water will eventualy swamp the effect if temperatures continue to rise.What I am not sure about is how long it will take to do that. The link is interesting in that it mainly deals with land ice and not much mention of artic ice, why is that?
|
|
|
Post by fascinating on May 27, 2013 13:13:04 GMT 1
Because the melting of floating ice in itself has almost no effect on sea level.
|
|
|
Post by marchesarosa on May 29, 2013 8:57:54 GMT 1
Remember the adjustment a few years back that involved the addition of 0.3mm per year for glacial isostastic rebound? sealevel.colorado.edu/content/what-glacial-isostatic-adjustment-gia-and-why-do-you-correct-itMarkx asks on WUWT "I’m interested to know why it is thought we should add the GIA of 0.3 mm per year – surely it is nett sea level which interests us … unless we are expecting the iostatic move to suddenly cease. In 100 years we are going to have to explain that the sea level includes 3 cm of ‘virtual’ sea rise." Just another way to keep the alarm bells ringing, I suppose. In a century's time there will be entirely unrelated problems to solve. I predict.
|
|
|
Post by buckleymanor1 on May 29, 2013 9:58:57 GMT 1
If the ice melts substantialy in the antartic then you will get wobble. The earths rotation about it's axis will be put out of balance.Depending on which bits of ice melt you could end up with cooling or heating. It will not be a case of last ice in first out.As all caotic systems are just that.
If that is included, then it's daft as you should include all take up of water like extraction of oil from the sea a "virtual" sea fall.If you are going to be thorough why take half measures.
|
|
|
Post by marchesarosa on May 29, 2013 10:10:59 GMT 1
It's just a sad transparent ploy to keep the claimed rise continuing.
|
|
|
Post by mrsonde on May 29, 2013 19:05:27 GMT 1
Typical answer what was expected! Your blatent willfull ignorance is in cherry picking the results to enforce your prejudice. No cherry-picking. I merely follwed Alan's suggested link. If there is anywhere a conflicting table, kindly provide a link to it. So what? Who's disputing it? All that's well understood, according to conventional physics - no surprise: it's a simple case of less homogenous ice structure, more loose liquid water, that's all. How on earth does this help your case that if it melts sea level will fall? Oh, hang on, I think I see your confusion. You don't realise this table ascends from a frozen state to the boiling, rather than the other way around, I surmise. You don't realise that liquid water freezes at nought degrees, perhaps? You think liquid water at, say, one or two degrees centigrade is less dense than liquid water at three, or four? Is that it? All you're looking at is a phase shift, buckley: ice is less dense than water because of a fundamental difference in structure. That occurs at four degrees, or at nought degrees, according from which state to the other you're describing.
|
|
|
Post by mrsonde on May 29, 2013 19:12:39 GMT 1
I know that water gets more dense when cooled below 4C, but I don't see how that would lead to decrease in sea level. The water released from ice melt would circulate around the globe, most of it becoming warmer than 4C, it will become less dense (expand) and cause a small increase in sea levels. It's not a small increase. There's a lot of water in the oceans. Overall, it's a larger increase than the land ice that's melted since the last glacial.
|
|
|
Post by mrsonde on May 29, 2013 19:19:50 GMT 1
At around 4C it's more dense. Either side of 4C it becomes less dense. Only if it's already been frozen. Why? Give your rationale, please. Ice is less dense, right? Therefore it floats. It's fresh, and it gets continually added to, with more fresh water, snowing on it, which is even less dense than ice. Therefore its displacement is less than its bulk content - very slightly. What does this have to do with anything, exactly?
|
|
|
Post by mrsonde on May 29, 2013 19:22:57 GMT 1
If the Arctic ocean was land-locked, separated from the world's oceans, then the melting of sea ice and introduction of melt water would, theoretically, lead to a tiny drop in the level of the water there. What "theory" is this then? The level would rise, according to how much melt water is introduced. The contribution of sea ice would be a small increase, too.
|
|
|
Post by mrsonde on May 29, 2013 19:26:01 GMT 1
It's gradual though.The melt water around the artic won't suddenly become a lot warmer temperature rises and falls as a gradient.The ice has to go from -30C to 4C and that will not happen overnight. The hypothesis is that it's melted. It's already over four degrees. What "effect"? Because sea ice has no effect on sea levels, that's why - I've given you a link, above, explaining that. There's a small increase - that's its only effect.
|
|