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Post by sigurdur on May 10, 2009 23:53:07 GMT
Please comment on what this link provides.
Thank youhttp://www.climatechangefacts.info/ClimateChangeDocuments/NilsAxelMornerinterview.pdf
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Post by kenfeldman on May 11, 2009 18:55:53 GMT
It's good for a laugh. Some of the arguements put forth are just so stupid as to be funny!
I liked the part that the Earth's angular momentum should change due to the rise in sea levels. Does anyone really think that a few mm per year would be enough to change the angular momentum of the Earth?
Anyway, Axel Morner is known to be a bit of a flake, who is a proponent of dowsing:
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Post by stranger on May 11, 2009 20:06:08 GMT
I see Feldman is not a farmer. If he were he would be aware that dowsing, water witching, can be the only cost effective way to find water on a place.
When the dowsers twigs/wires or whatever the dowser uses come together and you are told to "dig here," you can bet money that you will find water. And a great many very hard headed farmers do exactly that.
As will most of the well drillers in my area, who will gladly guarantee a producing well provided the location has been chosen by a dowser. But if you want a well next to the kitchen it's money up front and no guarantee at all.
Now, the sea level question is quite another matter. For some reason global warming advocates are prone to calling on mysterious uplifts and such when you point out this place or that where the flood tide level used to be higher. I could point you at a few of those places myself - and I have been told of many others.
It seems beyond reason that the tides have diminished in a century. The more so, since the distance between flood and neap tide levels is unchanged. But it's either believe that - or believe that considerably more water is locked up in ice and the AGW fanatics are wrong.
Stranger
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Post by hilbert on May 11, 2009 23:48:23 GMT
Ken Feldman writes:
Well, why not crank the numbers? Suppose we have a 5mm high layer of water extending, say, in a 1000 km band about the equator. Volume = .005 x 1,000,000 x 6380 x 1000 x 2 x pi = (approx) 2x10^11 m^3 Mass of water in band = 1000 kg / m^3 * Volume = (appox) 2x10^14 kg
If I recall correctly, the angular momentum of a uniform ball of mass M_e is 2/5 x M_e x R^2 x w, where w is omega, the angular velocity. A circular band at the same radius and speed would have angular momentum M x R^2 x w, so the ratio is just 5/2 x M / M_e. With M_e = 6 x 10^24 kg, this gives a ratio of about 8.35 x 10^(-11). (This is also the change in the angular momentum).
This translates to 2.5 ms change in a year. I don't know, but it's quite possible that this is in the range of detectibility. Certainly the matter is not out of the question.
If the sea level rise were uniform, the effect could be substantially larger.
So, perhaps not so stupid after all, eh?
(assuming that I did the numbers right)
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Post by ron on May 12, 2009 1:37:48 GMT
Didn't we talk about this once before in regards to the damming of rivers to produce high-altitude man-made lakes?
I can't find it.
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Post by steve on May 12, 2009 10:05:22 GMT
hilbert,
Pleased to see someone take this on mathematically. The problem I have with Axel-Mörner is that he has come out with this statement without really providing a mathematical justification.
I did it slightly differently.
IIRC, it is said we've had 20cm sea level rise since 1900. Roughly half of sea level rise is due to thermal expansion, and half is due to glacier melt.
Angular momentum = moment of inertia times angular velocity
Angular momentum = 2/5 * mass * radius^2 times 2pi/(length of day)
If we keep angular momentum, mass and the shape of the earth constant (ie. assume a uniform sea level rise) then:
Length of day is proportional to the radius of the earth squared.
So a 10cm expansion in the earth would slow it by 3 milliseconds per day.
But, since the bit that is expanding, water, is 1/5 the density of the earth, we have to reduce this number by about 5 to 3/5 milliseconds per day.
And the oceans cover the 2/3 of earth, so that brings us to 0.4 milliseconds.
10cm sea level rise from thermal expansion is probably all we've had so far, so this figure can be compared with the given rate of 1.7 ms per century slow down.
On the other hand, the rest of the sea level rise is due to glaciers. Some of these are at the top of mid-latitude and equatorial mountains. So we could be talking about a drop in altitude of 4-5 kilometres for some of the water which will speed up the earth's rotation by vastly more than a similar amount of sea level rise.
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Post by hilbert on May 12, 2009 13:36:25 GMT
Steve,
I'm not sure about the "vastly" part, as 2 x delta(r)/R is less than 1 part in 1000. More importantly, I would think that the amount of water in equatorial or mid-latitude glaciers that melts would be small, *but* I have not done the calculation.
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Post by steve on May 12, 2009 16:31:47 GMT
Steve, I'm not sure about the "vastly" part, as 2 x delta(r)/R is less than 1 part in 1000. More importantly, I would think that the amount of water in equatorial or mid-latitude glaciers that melts would be small, *but* I have not done the calculation. Yes, you are right. If anyone has access to Axel-Mörner's calculation, that would be great.
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Post by rustyphillips on May 21, 2009 15:56:33 GMT
Well, why not crank the numbers? Suppose we have a 5mm high layer of water extending, say, in a 1000 km band about the equator. Volume = .005 x 1,000,000 x 6380 x 1000 x 2 x pi = (approx) 2x10^11 m^3 Mass of water in band = 1000 kg / m^3 * Volume = (appox) 2x10^14 kg If I recall correctly, the angular momentum of a uniform ball of mass M_e is 2/5 x M_e x R^2 x w, where w is omega, the angular velocity. A circular band at the same radius and speed would have angular momentum M x R^2 x w, so the ratio is just 5/2 x M / M_e. With M_e = 6 x 10^24 kg, this gives a ratio of about 8.35 x 10^(-11). (This is also the change in the angular momentum). This translates to 2.5 ms change in a year. I don't know, but it's quite possible that this is in the range of detectibility. Certainly the matter is not out of the question. If the sea level rise were uniform, the effect could be substantially larger. So, perhaps not so stupid after all, eh? (assuming that I did the numbers right) hilbert (& steve) out of curiosity - would you please redo the numbers to compare today vs 20,000 years ago when sea levels were 130 m / 400 feet lower (the oceans water was sequestered as polar ice) same 1000 km band should be sufficient, but salt water density is ~ 1030 kg/m3..... (you used 1000) one question though - salinity & density would be higher in ice age waters vs today - perhaps use 1040 kg/m3 as density for ice age sea water, or just use todays density with an * next to density (as an area of future study) One would think that 400 feet of water removed from the equator and stored at the poles would mean the planet would have rotated (ever so slightly?) faster during the ice age I come up with 4 seconds a day / 24 minutes a year, a lot less than the leap year adjustments we do today.... probably beyond the ability of the greatest scientists of Atlantis to detect. or is the thinking that the "Post glacial rebound" theory would also apply to the worlds oceans - that after removing the weight of that water the crust would bulge outward at the equator and the poles would sink.... (counteracting any changes in water / ice mass distribution & impact on length of day/ speed of rotation)
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Post by steve on May 21, 2009 17:27:00 GMT
It's a bit more complicated, because over 20000 years, the earth has slowed by about a minute per day due to tidal friction - more than 10 times your estimate of 4 seconds.
Also, the extra ice on the earth's crust at the poles would have depressed the land their and pushed out the equator a bit, so balancing out some of the effect.
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Post by magellan on May 22, 2009 1:28:57 GMT
It's a bit more complicated, because over 20000 years, the earth has slowed by about a minute per day due to tidal friction - more than 10 times your estimate of 4 seconds. Also, the extra ice on the earth's crust at the poles would have depressed the land their and pushed out the equator a bit, so balancing out some of the effect. Why don't you cite sources? www.newscientist.com/article/dn11555news.bbc.co.uk/1/hi/sci/tech/1816860.stmTake your pick.
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Post by hilbert on May 22, 2009 1:36:14 GMT
So, it will spin faster in the US and slower in Europe. Must be the time chage. :-)
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Post by hilbert on May 22, 2009 1:45:31 GMT
So, basically, you just pretend that a belt around the earth acts like a loop, which has moment of inertia of m * r^2, where m is the mass of the belt, and r is the (equatorial) radius. You could make the assumption that putting the mass on the poles is an effect of much less sensitivity, since it would not change the moment of inertia a lot.
My earlier calculation was to demonstrate that the effect could be measurable, so I used more of an extreme case; the actual effect would probably be larger.
You might wish to take the moment of inertia of a shell (2/5 mR^2 - 2/5 mr^2), where R is the larger radius, and r is the smaller radius, and compare that to ice piled up near the poles (but with some realistic size, perhaps). I don't know that the density of sea water matters, compared to the density of pure water, since it seems to be only about 3%, and I'd be happy to get an answer accurate to 20%.
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Post by rustyphillips on May 22, 2009 3:33:16 GMT
It's a bit more complicated, because over 20000 years, the earth has slowed by about a minute per day due to tidal friction - more than 10 times your estimate of 4 seconds. Also, the extra ice on the earth's crust at the poles would have depressed the land their and pushed out the equator a bit, so balancing out some of the effect. are we not saying the same things? Im curious though - you mention tidal friction - does the additional 400 feet of oceans water (since 20,000 years ago) come into play in that or is ice age melt ignored?
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Post by steve on May 22, 2009 10:50:31 GMT
It's a bit more complicated, because over 20000 years, the earth has slowed by about a minute per day due to tidal friction - more than 10 times your estimate of 4 seconds. Also, the extra ice on the earth's crust at the poles would have depressed the land their and pushed out the equator a bit, so balancing out some of the effect. are we not saying the same things? Im curious though - you mention tidal friction - does the additional 400 feet of oceans water (since 20,000 years ago) come into play in that or is ice age melt ignored? I wasn't meaning to disagree with you. I was just saying that there appear to be a lot of impacts on the earth's rotation speed, so to me it seems it might be hard to separate one from the other. Magellan's link about the impact of winds was interesting. I can imagine that high frequency variations of the orbit (ie. day-to-day) might be attributable to day-to-day wind changes, but unless our maths is wrong, their figures seem to be much smaller than the slow-down due to tidal forcing and the potential changes due to sea level rise, so would be harder to tease out in the long run. I'd still like to see Axel-Mörner's figures.
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