Arctic Sea Level Falling? 368
HRH King Lerxst with a link to BBC News' report that "Arctic sea level has been falling by a little over 2mm a year — a movement that sets the region against the global trend of rising waters. ... It is well known that the world's oceans do not share a uniform height; but even so, the scientists are somewhat puzzled by their results."
Could Be A Number Of Things (Score:4, Insightful)
Funny things happen when you have solid H2O in liquid H2O that, on a large scale, are probably not well understood. I'm not a physicist but you have heat dissipation as Newton's Law of Cooling goes into effect and a multitude of climate issues. I can speculate on a few things:
If there's one thing that Slashdot is good for, though, it's testing half cooked theories! My fellow colleagues, I welcome you to point out the scientific flaws in my above hypotheses!
Re:Could Be A Number Of Things (Score:2, Insightful)
As the water becomes warmer, it is more prone to evaporation on the surface from the sun. Previously, less water would evaporate and keep the water levels slightly higher but now the difference in temperature at the surface is less making the water more easily transferred into a vapor.
Possible, but this would then result in more cloud cover. While this may be happening, I haven't seen any reports saying its happening. Of course more cloud cover would result in less light hitting the surface and thus re
Re:Could Be A Number Of Things (Score:5, Insightful)
This occurs because the ice is less dense than the water.
Nope. The ice cubes will rise a bit out of the water because they're lighter than water. They rise until they replace exactly the volume of water they'd have once molten.
So while they melt, the water level stays exactly the same (modulo influences of salt and temperature).
Re:Could Be A Number Of Things (Score:3, Insightful)
Of course, there are all sorts of factors that affect the levels in a given location, and without models, it's hard to say what's really the issue. What would seem a likely cause to me is oceanic conveyor action; if southward flows i
Re:Could Be A Number Of Things (Score:2, Insightful)
This is actually due to other things. 1kg of ice floating in water displaces the same volume as 1kg of fresh water. When the 1kg of ice melts, it becomes 1kg of fresh water, filling the ice's hole perfectly. Now, if you fill a glass with ice then add water, the ice cannot all float and some pieces are wedged against the sides of the glass, so it displaces more water than it would in a buoyant state.
As the density of the water around the ice increas
Re:Could Be A Number Of Things (Score:3, Informative)
This occurs because the ice is less dense than the water"
Completely untrue, if the ice is free-floating. This only holds if the ice is held under water by the ice on top of it & physiscal restraints on movement of the ice.
Try this one: Take a large-diameter container, place enough ice cubes in it such that when it is filled with water, ther
Re:Could Be A Number Of Things (Score:5, Funny)
It occurs because of either witchcraft or Jesus' love, not your "density".
Re:Could Be A Number Of Things (Score:2)
Re:Could Be A Number Of Things (Score:2)
not if that glacier was floating in the water. Actually as rocks on the glaciers melt through (heavier than water), or fall off, the ocean level would drop, not rise, because the glacier displaces the same amount of water per weight, but a rock sinking doesn't. (the rock floating on a glacier was displacing it's weight in water: upon falling off, the glacier rises up displacing less water than that of th
Isostatic rebound (Score:4, Informative)
Nice speculation. But since the end last ice age most of the coastlines surrounding the Arctic Ocean have undergone isostatic rebound [montana.edu]. Most of these areas were highly glaciated and heavily loaded with ice. Once the ice was rapidly removed the land maintained bouyant equilibrium by rising. Apparent sea levels have been falling in these areas for 1000's of years. The only question is how long it will continue and how isostacy and sea level rise interrelate in different areas.
Re:Isostatic rebound (Score:2)
An interesting item is that the global sea level is rising.
Of course, the real answer is that the water up there is cold, and cold water makes things shrink ;-)
Re:Isostatic rebound (Score:2)
Re:Isostatic rebound (Score:2)
Yes, and measuring a surface with variable size waves and sea ice in different parts of the year. -2.0mm with 10cm errorbars.
Re:Isostatic rebound (Score:3, Interesting)
Re:Could Be A Number Of Things (Score:4, Insightful)
"Some force (moon, internal gravity, spinning of the earth, sun, etc.) is causing the water to accumulate at the equator which in turn reduces the water at the poles. "
Not so much a force, but a lessening of one. The centripetal force of the spinning earth makes the oceans deeper at the equator. The viscosity of the water counters this. The viscosity is lessened with heat. Bingo!
Re:Could Be A Number Of Things (Score:2)
Actually it is just a geodesy affect. The satellite is drifing 2mm away from the earth and back every time it passes over the artic.
Re:Could Be A Number Of Things (Score:2, Insightful)
Re:Totally off-topic reply here.... (Score:2)
The way the green "title" line, the gray "by" line and the text are aligned vs. indented makes the distinction between message, parent and GP blend and disappear. If they made the text of the message body align not with the text of the gray and green "boxes" but with the left edge of the gray/green area itself, it would make everything clearer IMO.
The way it is now, when viewing two messages at the same "level" of indent, you get the illusion that the bottom message is one level higher, almost..
First guess (Score:2, Interesting)
Re:First guess (Score:2, Interesting)
Freshwater ice is less dense than fresh water (which is less dense than salt water). As the ice melts it occupies a smaller volume (which is of course why ice floats). The difference is a fairly significant percentage and may explain the sea level drop. This in turn is evidence of large amounts of fresh water forming in the arctic and this leads to the theory behind slowing the gulf stream down.
However most ice on oceans is from seawater: "Sea ice, formed in saltwater, a
What? (Score:5, Funny)
Re:What? (Score:2)
Re:What? (Score:4, Funny)
Re:What? (Score:2)
Of course... (Score:3, Insightful)
Re:Of course... (Score:2)
OK, that's a reasonable opinion to hold. But why would we accept your unsubstantiated opinion against the consensus opinion of people who do not about climate?
Not a surprise (Score:2, Funny)
Re:Not a surprise (Score:2)
Re:Not a surprise (Score:2)
It is a scientific fact that ice is less dense than water due to the hydrogen bonds and shape of the molecule. This is why ice floats on water. I'm agreeing with you by the way. My evaporation comment was a joke.. and to point out a potential flaw in the test.
It never occurred to me that the density of water in liquid or ice form would be enougn to show a difference in the ocean levels. I have always assumed there is so much more ice above the water level that the oceans would certainly rise
Global warming? (Score:2)
Re:Global warming? (Score:3, Informative)
Re:Global warming? (Score:2)
"Global Warming" is total bunk (Score:5, Insightful)
It means nothing of the sort my friend. In fact as scientists analyse global climate, they seem to be slowly, subtlely distancing themselves from the theory/term of "Global Warming". Have you noticed that authorities on the subject--even the most ardent supporters of things like the Kyoto initiative--now almost NEVER use the term anymore? The correct term is "Global CLIMATE CHANGE" because EVERYONE agrees that the earth is not universally warming up (some areas are, and others are getting cooler), and they aren't even convinced anymore that the AVERAGE gloabl temperature will continue to steadily rise. What they DO agree upon is that the climate is CHANGING--they point to evidence of changing weather patterns and more "extreme weather"--we'll get more Katrina's in the Gulf of Mexico and huge, freezing blizzards in maritime Canada and expanding deserts in Africa. The general consensus is still that CO2 from human activity exacerbates the problem--it's just that scientists now cover their butts with more general terms like "climate change" because truthfully, NOBODY has a handle on what exactly is going to happen.
The situation might go as you state, but there are a number or drastically different predictions as well:
warmer -> more evapouration -> more cloud formation -> sunlight blocked -> cooler
or
or
warmer -> melting polar ice -> lower ocean temperatures -> shifting weather patterns -> more "even" climate (warmer & wetter towards poles, cooler in the equatorial region)
NOBODY knows what will REALLY happen--it is all guesswork (albeit really educated guesswork). Although those who say human activity/CO2 emissions have no notable effect on the planet are generally dismissed as crackpots (and rightly so), the scientific community is finally acknowleging--at least a bit--that they don't know the ultimate effect, which is significant becasue high-profile research organisations really hate to admit they don't know something (almost as much as they hate admitting they're wrong). And here is one to cheer you up--there is a growing contingent of scientists that say "yes, human activity has altered our climate, but the can is open and the worms have long since escaped--we are past the point of fixing things".
Nope, sorry, you missed it (Score:3)
But what it means in terms of climate is related to the true scientific meaning of the term temperature--a measure of the total energy in a system. "Warming" simply means that more and more energy is being stored by the system. Think of a fly wheel being spun up faster and faster.
EVERYONE agrees that the earth is not u
Global Dimming vs Global Warming (Score:3, Informative)
Quote: Some scientists now consider that the effects of global dimming have masked the effect of global warming to some extent and that resolving global dimming may therefore lead to increases in predictions of future temperature rise.
Re:Global Dimming vs Global Warming (Score:2)
Elementary Physic... Elementary... (Score:2)
This is normal Earth rotational speed oscillation on an eon scale.
Move along, nothing new to see here.
Slashdot isn't peer reviewed (Score:2, Insightful)
Climate change is a kind of political topic, and this means that everyone who has a political opinion pretends to be an expert on the subject.
The Wright answer (Score:5, Funny)
The Precautionary Principle (Score:3, Insightful)
This produces problems when science and politics come together, because of the way science is treated by popular culture and popular politicians. Essentially, science is popularly viewed and portrayed as being a source of certainty. This is why the extremely small number of global warming naysayers always are referred to as scientists (irrespective of whether their credentials are respected or relevant). It creates the illusion that "science" has yet to arrive at its intended goal: absolute certainty. But as any good scientist will tell you, scientific truth is always provisional.
Thus, the trouble with doing something about global warming is that there is a disjunction between the sort of certainty (absolute) that politicians facing re-election and pressure groups want before acting, and the sort of certainty (provisional, always subject to revision) that scientists can, in good faith and following the strict methodology of science, give. Enter the precaution principle, which basically states that if you have a reasonably likely possibility of really bad future outcomes, you should try to do something about it, even if it's possible those outcomes don't come to pass. To me, global warming fits this scenario.
Re: The Precautionary Principle (Score:2)
Politicians don't like absolute certainty. They merely want to be able to construct the appearance of absolute certainty when it suits their agenda, and the appearance of absolute doubt when that suits their agenda.
Re:The Precautionary Principle (Score:2)
To me, the typical proposals that are bandied about also fit that scenario. To wit, proposing that the western economies/cultures most able to continue their existing work in making more efficient use of energy "fix" the problem by cri
Re:The Precautionary Principle (Score:3, Insightful)
It will because everyone is an extremist on one side or the other. I see articles all the time about how there should be $3.00/gallon of gas tax added, or SUV owners should be fined, Fuel mileage standards should be increased in unreasonable amounts, etc, etc... If some of these ridiculous actions go into place it will cripple the economy. OTOH, constructive things like Nuke plants, pu
Re:The Precautionary Principle (Score:2)
You missed a key element, though, which is that it only makes sense to do something if: (a) your actions are likely to have a positive (rather than no or negative) effect on the problem and (b) the benefits outweigh the costs. Now, I'm not convinced that global warming is substantially more likely to have negative effects than positive ones, and I'm even less convinced that, if it were demonstrably more likely to have negative effects, we would feasibly be able to
The Precautionary Principle Says Says Use Itself (Score:2)
Did humans, when first inventing the automobile, use the precautionary principle? No, and we are better off with them. Think ambulances.
Did humans, when inventing computers, use the precautionary principle? No, and we are better off with them. Sh
The Chicken Little Theory (Score:4, Funny)
Re:The Chicken Little Theory (Score:2)
How many desalinization plants are being built? (Score:2)
As the global population shoots up, and people continue trying to find ways to make inhabitable land habitable, I only see this trend increasing.
Is it possible that we could end up sucking up enough water out of the oceans and redistributing it that we could change not ocean levels?
At first thought
Umm... it's all at the gas station (Score:2)
If that isn't the answer, than I'm sure Mayor Adam West's research will not have been in vain... (Family Guy reference for those not in the know)
Blame the dolphin's (Score:3, Funny)
The end is near - I knew it.
Re:Blame the dolphin's (Score:2)
Remember, lead dolphins and Styrofoam dolphins displace the same amount of water.
Nonetheless, your Hitchhikers' Guide reference is appreciated.
Should be self-evident (Score:2)
Re:Should be self-evident (Score:2)
Frozen water expands, taking up more room. When the ice melts, the volume it takes up reduces, lowering the sea level.
Frozen water expands, taking up more room, but also lowering the density. Ice on land that melts goes into the sea, theoretically raising the water level. Floating ice melts, becoming more dense, thus the part that was above the water now displaces space as well, resulting in no net change in the water level. So a positive amount of displacement from runoff added to no change in displacem
Smug! (Score:2)
--Rob
The Physics (Score:2, Informative)
huh (Score:2)
It's all relative. (Score:3, Interesting)
Change
Arctic sea level has been falling by a little over 2mm a year - a movement that sets the region against the global trend of rising waters. A Dutch-UK team made the discovery after analysing radar altimetry data gathered by Europe's ERS-2 satellite.
to
Europe's ERS-2 satellite has been falling by a little over 2mm a year. A Dutch-UK team made the discovery after analysing radar altimetry data gathered over the Arctic sea level.
Not really a surprise (Score:3, Interesting)
No one knows why - forming mineral hydrates, some other form of leaking into the earth itself, or global cooling - it's all speculation right now, just like global warming. The truth: The world is a complex place and we're not even close to understanding it.
BTW: Remember when "all the world's climate experts" warned of global cooling and an impending ice age only around 30 years ago? (Which would, of course, require many of the same environmental policy changes wanted by the global warming crowd now.) Those who forget history are doomed to repeat it.
Re:Global Cooling (Score:3, Informative)
if you want to be a pedant, parts of the middle of certain ice sheets are thickening do to increased precipitation, which is due to excess evaporation from warming. the rest of these ice sheets are melting, and more is melting than is thickening.
but thanks for playing "clouding the issue with Dan Grossman" Don, tell him what he didn't win!
Re:Global Cooling (Score:2)
"Premise is true because of thing I say is true"
thing isn't true..
"Ok, then, but Thing is not true because of previosly unmentioned, but obvious extrapolation of Premise. so, Premise is still true."
Re:Global Cooling (Score:4, Insightful)
Time [72.14.209.104],
Newsweek [washingtontimes.com],
etc. [wikipedia.org]
-Peter
Re:Global Cooling (Score:2)
Re:Global Cooling (Score:2, Informative)
err, I suppose that should be in quotes.
Seriously cant that guy just go back to spain or wherever the hell he disappeared to after losing in 2000.
Re:Global Cooling (Score:2, Informative)
http://news.bbc.co.uk/1/hi/world/europe/3922579.s
Whoever am I to believe about this scientific issue...scientists from the Geological Survey of Denmark and Greenland, or a keyboard jockey from Slashdot?
Re:Global Cooling (Score:2)
Re:Global Cooling (Score:4, Informative)
Because they don't know how to swim?
They ate less than twenty minutes before entering the water?
Just too damned fat?
They're drunk?
Suicide pacts?
Forgot their water wings?
Their star is falling while their pollyanish wives are reaching the big time?
They were all carrying Hamlet's child?
you get a big, fat, WTF (Score:2)
The biggest problem, in my opinion, with the global warming debate and other contentious scientific issues is that the role of evidence is being reversed. Evidence should come first, and from the evidence we form conclusions. The relative perceived veracity of a given theory should fluctu
Re:you get a big, fat, WTF (Score:2)
-stormin
Re:you get a big, fat, WTF (Score:2)
Actually, I would argue global warming is evidence not theory. There is plenty of data showing globally rising temperatures. The theory is that there is a significant human contribution to that rising temperature due to burning of fossil fuels. One prediction of this theory is that carbon in the air and water would show a isotopis signatures con
Re:Gets you Al Gore! (Score:2, Insightful)
There is a scientific consensus that it exists. The controversy is over how much humans speed it up.
the worst figures I've seen say we've increase one degree Fahrenheit in the last two-hundred years. One degree? For the largest polluting, greatest industrial achievements in the history of man? That sounds pretty damn stable to me.
You do realize how much energy it takes to raise an entire planet by
Re:Gets you Al Gore! (Score:2)
A common myth. Even the ancient Greeks knew it wasn't true, though.
There was a scientific consensus that Black people were inferior to White people. There was a scientific consensus that Iraq had WMDs.
I think we're working off a different definition of "science" here.
disregarding the fact that 50 years ago these same kinds of figures would indicate that the planet is cooling...
Ooh, more myths. http://www.realclimate.org/index.php?p=94 [realclimate.org]
Re:Gets you Al Gore! (Score:3, Interesting)
Second, get your facts straight. It's 1 degree celsius..
Re:Gets you Al Gore! (Score:2)
No, that's not how science works. Not at all.
Re:Gets you Al Gore! (Score:2)
We've GOT to effect the climate. We BETTER be "self-important".
The climate WILL change. It is a certainty.
Re:Gets you Al Gore! (Score:2)
Re:Gets you Al Gore! (Score:2)
You don't need to be proven that Global Warming doesn't exist, you should force people to prove it does exist.
Bullshit, things don't work that way. To generalize your argument, you're saying that if we put forth a hypothesis A, then the burden of proof is to prove A. But we can just as easily construct a hypothesis B, which is the opposite of hypothesis A, and now you would say that the burden of proof is to prove B, that is, to prove not A. So in fact, your assertion that global warming is "false until
Re:Gets you Al Gore! (Score:2)
Re:Cue anti-GW trolls in 3...2...1... (Score:2)
The bulk of the earth is in motion, and very little is static. I
Re:Cue anti-GW trolls in 3...2...1... (Score:2)
Cue ... questioning assumptions (Score:2)
Reminded me of a news story I saw a while back about a group of islands slowly disappearing under the water. Of course the culprit is global warming melting arctic ice resulting in higher water levels.
Then again, nobody seemed to even consider that erosion may be lowering the land level instead.
Which brings back the question of how are the measurements being made? From TFA it appears to be a very complex process. I simply don't have the expertise and
Re:Cue ... questioning assumptions (Score:2)
Oh my god! Something is eroding the Artic Ocean! Soon there will be no more oceans and we will be hot AND dry!
-matthew
Re:Cue ... questioning assumptions (Score:2)
Mainstream "news" stories about science are notoriously short of facts and also are quite often incorrect.
Hey! there's my cue! (Score:2)
Re:Hey! there's my cue! (Score:2)
Re:Hey! there's my cue! (Score:2)
You conservatives can dish it out but you can't take it. Admit it, you have a little chuckle at the verbal diarrhea spewing out of th
Re:Hey! there's my cue! (Score:2)
Re:It shouldnt take a mega-catastrophe to get it (Score:5, Insightful)
Re:It shouldnt take a mega-catastrophe to get it (Score:2)
In a system like globe, the sum of all randomnesses and fluctuations sum up to one observeable final system.
Re:It shouldnt take a mega-catastrophe to get it (Score:2)
You may be familiar with the name James Hansen? AKA the scientist the Bush administration is accused of trying to silence?
He's one of the most strident global warming supporters,.
He gave an interview a while back where he criticised armchair climatologists (my words, not his) who tried to blame every little thing on global warming (that's weather, geology... not climate). The science doesn't support that, and doesn't need that kind of "junk" (again, my word, not his) to be believed. Worse
Re:It shouldnt take a mega-catastrophe to get it (Score:5, Insightful)
They don't know.
To take action when one doesn't know what is happening could make things worse.
Of course we know there are oddities occuring, but that is the key word - oddities. Its odd when we don't understand.
The problem with Climate science is that it hasn't been all that long since we had the tools to truly understand it. Hell we have had only a couple of decades where we could accurate measure temperatures around the globe. The accuracy increases each year and yes we will learn something from it. Some things we learn will proven "common" beliefs to be totally wrong, others may actually prove some concepts.
That is the crux of the Global Warming issue. We don't know enough to be sure what all the causes are and if actions we take will have the desired effect. If we knew the climate as well as some think they do then why are simple things like weather prediction difficult? Easy, its difficult and not simple, its difficult because we don't know all the variables. We know the obvious ones, well at least we think we do.
So before flying off the handle we need to realize we are not as smart as we think we are.
'Lobby'ists - take them into account (Score:2)
Some big corps have paid 'lobby'ists, and these people are blurting out all kinds of fact and fiction to hold their bidder's case.
Same is the situation with global warming. Industry interests do not want things to be decided. They want to continue emission, continue expansion unchecked and unregulated in regard to environment. This is why bush have not signed in kyoto treaty.
It is folly not to get there are hordes of lobbyists, 'scientists'
Re:'Lobby'ists - take them into account (Score:2)
Whether or not a president signs it is immaterial aside from symbolism. President Clinton signed onto the protocol, but never submitted it to the Senate for ratification because of the prior overwhelming vote against it that would have been an embarrassing defeat for his administration.
Re:'Lobby'ists - take them into account (Score:2)
Re:'Lobby'ists - take them into account (Score:3, Insightful)
Re:It shouldnt take a mega-catastrophe to get it (Score:2, Insightful)
Re:Centrifugal Force? (Score:2)
In this analogy, the water levels at the edge would correspond to the water at the equator, and those levels being higher is actually consistent with what he was describing.
Oh, and I think you mean centripetal force.
Not likely, since centripeta
Re:Centripetal Force!! (Score:2)
Not likely, since centripetal force is whatever pulls a revolving object inward. Suggesting that it (in this case, gravity) is responsible for lifting water upward at the equator is a bit nonsensical. Centrifugal force, while a technically incorrect term (since it's really the combined effect of angular momentum and inertia), is what does that.
No, the centripetal force, provided as you say by gravity, has to provide the inward acceleration of the water. (Oth
Re:Is it just me? (Score:2)
Re:But... (Score:4, Funny)
It's an optical illusion (Score:2)