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."

Isostatic rebound

[amightywind]

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:Global Cooling

[Anonymous Coward]

" The polar caps are actually *growing* this year, as they have been recently, not shrinking."

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!

Global Dimming vs Global Warming

[wklam]

http://en.wikipedia.org/wiki/Global_dimming [wikipedia.org] [Wikipedia on Global Dimming]

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 Cooling

[Tweekster]

but but but Gore is an environmentalist.

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

[Anonymous Coward]

Hmmm...but this article says that the glaciers in Greenland are melting and retreating from the sea, not growing larger.
http://news.bbc.co.uk/1/hi/world/europe/3922579.st m [bbc.co.uk]
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

[Quinn]

Then why are polar bears drowning in record numbers?

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?

Re:Global warming?

[shotfeel]

No, more water vapor = more clouds = more light reflectd -> cooling

Re:Could Be A Number Of Things

[Red Flayer]

"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"

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, there is a single layer of cubes with room for them to move around a bit. Fill container until water almost spills over.

Observe the level of the ice -- there is some that sticks up out of the water over the level of the container. What happens when the ice melts? The water level remains the same -- this is because the ice displaces the volume of water it would occupy were it to melt.

The Physics

[remnant_x]

By no means am I an expert in the field, but I do have a firm head on my shoulders, and am confused by the lack of any "discussion" section in the BBC report. So here is a part of mine. Although it is common to say that the top of a continuous body of water is all at the same elevation (a fact surveyers use extensevly to reduce costs), that statement is wrong. The tops of water bodies follow an equipotential surface. This means that each top point will have the same potential energy. In small surfaces, such as lakes, the difference between the equipotential surface and the equi-elevation surface is nearly zero, so it is not taken into account. In larger bodies, such as the entirety of north America, or even the world, spherical coordinates are not as useful. Geoids have been used for many years to approximate the equipotential surface on the earth (search NAD27) but even they do not capture the peculiarities that occur with local lead outcroppings or other local density peculairities on the earth. Another coomonly understood fact is that water is most dense at 34 degrees farenheight. A not commonly understood fact is that the global ocean circulation patterns are very slow. Put these three ideas together and one can figure out that it is not the oceans that have been lowering, but that there is more cold water near the polar ice caps then there was before becasue of the increased rate of ice melt. This effect has increased the density of the polar ice cap region and decreased the elevation of local equipotential curve. The decrase in absolute elevation is true, but the equipoential elevation has been rising. If I am wrong on any of this, please correct me. Have a good day.

The Inconvienent Truth is...

[WED Fan]

...that most of the global warming crap is just that, crap. Junk science. Once they, anti-capitalist, couldn't sell the global cooling idea in the early 70's (most of you probably don't remember that), they switched to global warming. The idea is to impact the American, or capitalist way of life. WATERMELON is apropo

The Canada Free Press [canadafreepress.com] just ran a very interesting article refuting the junk science prefered by the likes of Al Gore.