Naked Science Forum

Life Sciences => The Environment => Topic started by: another_someone on 15/06/2006 15:11:33

Title: Arctic sea level has been falling
Post by: another_someone on 15/06/2006 15:11:33
http://news.bbc.co.uk/1/hi/sci/tech/5076322.stm
quote:

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.

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.

Global sea level is expected to keep on climbing as the Earth's climate warms.

To find the Arctic out of step, even temporarily, emphasises the great need for more research in the region, the team says.

 "We have high confidence in the results; it's now down to the geophysics community to explain them," said Dr Remko Scharroo, from consultants Altimetrics LLC, who led the study.





George
Title: Re: Arctic sea level has been falling
Post by: Andrew K Fletcher on 16/06/2006 09:03:25
Said all along you can't increase the amount of water in the ocean without increasing the over all downward pressure of the ocean. This increased pressure causes the ocean beds to be squeezed to greater depths, and this in turn causes more quake activity and volcanic eruptions as the forces are evenly compensated for.

The ultimate end to this is that the ocean bed will reach the the molten magma with sufficient force and volume to trigger the oceans into their own form of global warming, which is very different to the global warming we know at present. But I don't expect anyone to hear this either.
 

quote:
Originally posted by another_someone

http://news.bbc.co.uk/1/hi/sci/tech/5076322.stm
quote:

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.

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.

Global sea level is expected to keep on climbing as the Earth's climate warms.

To find the Arctic out of step, even temporarily, emphasises the great need for more research in the region, the team says.

 "We have high confidence in the results; it's now down to the geophysics community to explain them," said Dr Remko Scharroo, from consultants Altimetrics LLC, who led the study.





George




"The explanation requiring the fewest assumptions is most likely to be correct."
K.I.S. "Keep it simple!"
Title: Re: Arctic sea level has been falling
Post by: another_someone on 16/06/2006 11:47:31
quote:
Originally posted by Andrew K Fletcher
Said all along you can't increase the amount of water in the ocean without increasing the over all downward pressure of the ocean. This increased pressure causes the ocean beds to be squeezed to greater depths, and this in turn causes more quake activity and volcanic eruptions as the forces are evenly compensated for.

The ultimate end to this is that the ocean bed will reach the the molten magma with sufficient force and volume to trigger the oceans into their own form of global warming, which is very different to the global warming we know at present. But I don't expect anyone to hear this either.



You can make very little difference to the amount of water in the oceans anyway.  The main difference people are talking about is how much of that water is frozen and how much liquid – but that is not a difference that will make any distinction to the downforce.

Yes, the burning of hydrocarbons does create a little bit more water (the burning of coal does not – but then most people seem happier with the idea of pumping more water into the atmosphere than pumping more CO2 into the atmosphere, and hydrocarbons produce a mix of water and CO2, while coal is pure CO2); but the amount of additional water so created is minuscule in relation to that which already exists in the oceans.



George
Title: Re: Arctic sea level has been falling
Post by: Seafang on 18/08/2006 00:10:54
I don't see why the big mystery, about the Arctic Ocean sea level falling.

That is exactly what the laws of Physics (even high school physics) say should happen.

And it was predicted to happen; see "Physics Today" for January 2005, Letters Section.

Oh; it was I who predicted it.

If you ever got out of a hot shower and got chilly then you understand exactly why the Arctic Ocean level will fall as the floating sea ice melts.

Why is it that so many so-called climate scientists don't seem to understand even basic high school physics ?

If those Dutch guys from Delft, or the UK members of the team can't figure it out for themselves; they can e-mail me and I will explain it to them.
Title: Re: Arctic sea level has been falling
Post by: VAlibrarian on 21/08/2006 22:38:11
The main point here is that this odd little bit of research does nothing to disprove the existence of global warming as a process. I therefore consider it a bit of a red herring.
In the long term, the impact of global warming on human existence will be very negative. That last sentence is far from controversial in scientific circles- it is considered a pretty safe assertion.

chris wiegard
Title: Re: Arctic sea level has been falling
Post by: crandles on 22/08/2006 00:02:07
quote:
Originally posted by VAlibrarian

The main point here is that this odd little bit of research does nothing to disprove the existence of global warming as a process. I therefore consider it a bit of a red herring.
In the long term, the impact of global warming on human existence will be very negative. That last sentence is far from controversial in scientific circles- it is considered a pretty safe assertion.

chris wiegard



This post looks like it is nothing more than handwaving. Someone could easily point out that if you accept evidence for global warming but dismiss evidence against as a bit of a red herrings then your conclusion that global warming is real could be not very meaningful.

Wouldn't it be better to say something more like: the research clearly indicates that globally sea level has risen and, as far as affirming or questioning global warming is concerned, it is the global result that matters not a regional difference?

I am not at all sure about the 'existence' or the 'very'. I wouldn't quibble if you had said the impact on human welfare could be very negative or will be negative.

Yes global warming is happening and yes it is due to us. However, the extent of the warming is controversial and even whether it is significant compared to other societal changes is debateable. Personally I think the risks of it being serious are far too great to ignore and more should be done.
Title: Re: Arctic sea level has been falling
Post by: daveshorts on 22/08/2006 17:10:02
If ice is melting in the artic then there will be less weight on the local crust so it will tend to float upwards, making the relative sea level lower. I don't know if their measurements were including this or not.
Title: Arctic sea level has been falling
Post by: mark71 on 02/06/2007 02:39:01
how do we know these polar ice caps are not melting because we forgot to replenish the ozone layer 15 years ago by launching those rockets up to the south pole with fresh ozone...or has everyone forgot. It may not be co2 induced global warming that will flood the world, but forgetfulness…

Title: Arctic sea level has been falling
Post by: dentstudent on 14/06/2007 11:26:22
If ice is melting in the artic then there will be less weight on the local crust so it will tend to float upwards, making the relative sea level lower. I don't know if their measurements were including this or not.
Just seen this post - Dave - do you mean Canada, Russia, Greenland etc, as there is no crust underneath the Arctic, or at least that is in contact with the ice, as the Arctic is floating....... This leads to something else I've wondered - much of Greenland is below sea-level due to the weight of the ice pack, so by how much will it rise if the ice completely melts?