Slashdot Mirror


Arctic Sea Level Falling?

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."

10 of 368 comments (clear)

  1. Could Be A Number Of Things by eldavojohn · · Score: 4, Insightful
    "I think it's a true statement to say the Arctic Ocean is the least well understood body of water out there" -- Dr Seymour Laxon, UCL
    I think that's because few other bodies of water have a massive chunk of ice in them ... with many more smaller chunks floating around.

    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:
    • 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.
    • Gravity pulls down on the free floating icebergs and it displaces the water. These icebergs are shrinking or being reduced greatly so the water height in the vicinity lowers slightly while the water levels around the world rise slightly.
    • The tides are becoming stronger and as the amount of water on the surface of earth increases, so does the effect of the moon on it. The moon pulls least on water at the caps and even more so on water near the equator.
    • 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.
    Like I said, this is pure speculation and I haven't thought out in advance the above propositions. But I'm going to speculate that there's an unknown effect that occurs when massive bodies of ice are half submerged in water on a planet. The basis of this effect is probably known in physical and chemical fields of science but we just haven't put them together to figure it out. Hopefully we can figure it out as these "discoveries" are oftentimes the foundation for more work and more discoveries that benefit mankind. Translation: curiosity spurs innovation.

    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!
    --
    My work here is dung.
    1. Re:Could Be A Number Of Things by Dr.+Hok · · Score: 5, Insightful
      Take a glass, fill it with ice cubes, and add water until it is just about to spill over. Then wait. As the ice melts, the water level in the glass decreases.

      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).

      --
      Say out loud: I'm an Aspie and I'm somewhat proud, I guess. Uh. Can I write an email in all caps instead? Hm...
    2. Re:Could Be A Number Of Things by Instine · · Score: 4, Insightful

      I am a physicist, and this is the closest you got to the most likely scenario (IMO).

      "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!

      --
      Because you can - or because you should?
    3. Re:Could Be A Number Of Things by EatHam · · Score: 5, Funny

      This occurs because the ice is less dense than the water.

      It occurs because of either witchcraft or Jesus' love, not your "density".

  2. What? by MrSquirrel · · Score: 5, Funny

    ...What?... I was THIRSTY, okay?

    --
    A computer once beat me at chess, but it was no match for me at kick boxing.
  3. The Wright answer by Ken+Hall · · Score: 4, Funny

    Maybe global warming is causing an increase in the sponge population.

  4. Re:It shouldnt take a mega-catastrophe to get it by RexRhino · · Score: 4, Insightful

    Except that weather is full of random fluxuations and anomylous local occurances. It is very bad science to say that every random weather patter that we can't explain is caused by global warming. It is fearmongering and political posturing, not science.

  5. The Chicken Little Theory by Atomm · · Score: 4, Funny

    The artic ocean has not fallen 2mm. The sky has fallen 2mm. This gives you the impression the ocean is down 2mm. ;-)

  6. Re:It shouldnt take a mega-catastrophe to get it by Shivetya · · Score: 4, Insightful

    But is taking "action" any better when we don't know the science behind it?

    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.

    --
    * Winners compare their achievements to their goals, losers compare theirs to that of others.
  7. "Global Warming" is total bunk by WebCowboy · · Score: 4, Insightful

    warmer = more evaporation = more water vapor in the air = more heat trapped and so on

    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 ... ... ... -> more cloud formation -> wetter weather -> more vegitation in once barren areas -> more CO2 uptake from vegitation -> less GHG and more O2

    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".