Let's Revisit Earth's Ice Accumulation

jwoodward48 wrote:

Tim the plumber wrote:

jwoodward48 wrote:

Tim the plumber wrote:
Perhaps they understand that the flow rate of the exit glaciers is the same as ever and that the rate of melting at the bottom of the ice sheet is the same as ever and that these figures are tiny in comparison with the deposition because they are engineers and don't need stupid basic concepts explained to them.

Whoa, whoa, whoa.

1. "The flow rate is the same as ever" - where are you getting that? How do you know that?

2. "these figures are tiny in comparison with the deposition" - Tim, do you understand equilibrium? Deposition and exit rate are normally equal.

The flow rate of the ice going down the exit glaciers is the same as always becaues the gradient of the glaciers and their thickness has not altered. So the dynamics of that means that the same forces apply to the same mass. Thus it's ****ing obvious!!!!

Sublimation, dude.

When they quoted the mass balance they have just talked about the whole of the ice!!!! They have stated that the whole of the ice is getting bigger by 2% every decade.

No, they have stated that the deposition rate has increased by 2%.

You do not know that the mass balance of Greenland is normally in equlibrium. It could be that ice has been building up on it since the it first did not melt in the center of it. That this process is just keeping on going. That it will end when we finnaly get out of the present ice age or Greenland moves away from the pole.

True, I can't necessarily deduce that the mass balance is falling from the report given, but then the mass balance of Greenland wouldn't necessarily mean anything for AGW - neither evidence for nor against.

jwoodward48 wrote: Tim, that's nonsense. You'd need 5m per year of deposition to have that sort of mass balance, even ignoring sublimation and calving and melting.

IBdaMann wrote:

jwoodward48 wrote: Tim, that's nonsense. You'd need 5m per year of deposition to have that sort of mass balance, even ignoring sublimation and calving and melting.

...based on your own personal observations?

Glacier Girl was buried in 268 feet of ice over 50 years. That's 1.634 meters per year. Hence 16.34 meters per decade. The landing site was at the southern end of Greenland where the thickness is between 10 meters and 1000 meters.

Let's assume, for the sake of discussion, something closer to the upper end, e.g. 800 meters thickness. An accumulation of 16.34 meters per decade would represent about 2% per decade accumulation of the ice mass balance.

That's just one example. Do you have any personal observations that run counter to that?

Surface Detail wrote: Bit of a logic glitch there. Your calculations make the erroneous assumption that accumulation is proportional to ice thickness when, if anything, the reverse is true. Accumulation is lowest towards the centre of the ice cap and highest towards the coasts.

IBdaMann wrote:

Surface Detail wrote: Bit of a logic glitch there. Your calculations make the erroneous assumption that accumulation is proportional to ice thickness when, if anything, the reverse is true. Accumulation is lowest towards the centre of the ice cap and highest towards the coasts.

No error on my part. You simply don't know what "accumulation" means.

I correctly computed the amount of ice mass that was accumulating in that example, both in an absolute sense and relative to the amount of ice beneath. The relative rate was about 2%. It's not my problem that you can't do basic math.

2% per decade increase in the ice mass balance.

Yep.


.

IBdaMann wrote:

Surface Detail wrote: Bit of a logic glitch there. Your calculations make the erroneous assumption that accumulation is proportional to ice thickness when, if anything, the reverse is true. Accumulation is lowest towards the centre of the ice cap and highest towards the coasts.

No error on my part. You simply don't know what "accumulation" means.

I correctly computed the amount of ice mass that was accumulating in that example, both in an absolute sense and relative to the amount of ice beneath. The relative rate was about 2%. It's not my problem that you can't do basic math.

2% per decade increase in the ice mass balance.

Yep.

Surface Detail wrote:Your math is fine; it's your logic that faulty.

Surface Detail wrote: You're dividing the accumulation where the plane is by your estimate of the total ice thickness at that point, and then assuming that the resulting figure is true for the whole ice cap.

Surface Detail wrote: You are, of course, also neglecting ice loss over this time.

jwoodward48 wrote: IB, that's gross. Ice doesn't melt or calf from its top.

IBdaMann wrote:

Surface Detail wrote: You're dividing the accumulation where the plane is by your estimate of the total ice thickness at that point, and then assuming that the resulting figure is true for the whole ice cap.

No, I did not make that assumption. I was doing the math for the net ice mass balance just in that area because we have actual accurate measurements and an accurate time frame.

Surface Detail wrote:

IBdaMann wrote:

jwoodward48 wrote: Tim, that's nonsense. You'd need 5m per year of deposition to have that sort of mass balance, even ignoring sublimation and calving and melting.

...based on your own personal observations?

Glacier Girl was buried in 268 feet of ice over 50 years. That's 1.634 meters per year. Hence 16.34 meters per decade. The landing site was at the southern end of Greenland where the thickness is between 10 meters and 1000 meters.

Let's assume, for the sake of discussion, something closer to the upper end, e.g. 800 meters thickness. An accumulation of 16.34 meters per decade would represent about 2% per decade accumulation of the ice mass balance.

That's just one example. Do you have any personal observations that run counter to that?

Bit of a logic glitch there. Your calculations make the erroneous assumption that accumulation is proportional to ice thickness when, if anything, the reverse is true. Accumulation is lowest towards the centre of the ice cap and highest towards the coasts.

jwoodward48 wrote:
The Greenland glacier is about 2 km thick. 81 m of accumulation over 50 years is 1.62 m per year, or 16.2 m per decade. 5% of 2000 m is one hundred. We've only measured 16% of the increase that you've claimed, or about one-sixth - but wait! That's assuming that there is no outflow. If you include the outflow, the number would be far less.

If you look at the shorter edges, the same deposition rate exists, but on less snow. That doesn't adequately show the relationship between the overall deposition and outflow.

Tim the plumber wrote:

Surface Detail wrote:

IBdaMann wrote:

jwoodward48 wrote: Tim, that's nonsense. You'd need 5m per year of deposition to have that sort of mass balance, even ignoring sublimation and calving and melting.

...based on your own personal observations?

Glacier Girl was buried in 268 feet of ice over 50 years. That's 1.634 meters per year. Hence 16.34 meters per decade. The landing site was at the southern end of Greenland where the thickness is between 10 meters and 1000 meters.

Let's assume, for the sake of discussion, something closer to the upper end, e.g. 800 meters thickness. An accumulation of 16.34 meters per decade would represent about 2% per decade accumulation of the ice mass balance.

That's just one example. Do you have any personal observations that run counter to that?

Bit of a logic glitch there. Your calculations make the erroneous assumption that accumulation is proportional to ice thickness when, if anything, the reverse is true. Accumulation is lowest towards the centre of the ice cap and highest towards the coasts.

How does that make hos maths at all wrong?

The average thickness of ice is less than 3km.

The rate of increase in mass balance is +2% per decade which I have always pointed out is huge. So big that I also have trouble imagining it.

IBdaMann wrote:

jwoodward48 wrote: IB, that's gross. Ice doesn't melt or calf from its top.

It's net. Reread my post.


.

jwoodward48 wrote:

IBdaMann wrote:

jwoodward48 wrote: IB, that's gross. Ice doesn't melt or calf from its top.

It's net. Reread my post.


.

You've described how the plane was buried under a certain amount of ice, right? Loss occurs mostly from the sides, not the top.

Surface Detail wrote:The mass balance is actually falling, as evidenced by altimetry and gravimetric analysis.

Tim the plumber wrote:

jwoodward48 wrote:
The Greenland glacier is about 2 km thick. 81 m of accumulation over 50 years is 1.62 m per year, or 16.2 m per decade. 5% of 2000 m is one hundred. We've only measured 16% of the increase that you've claimed, or about one-sixth - but wait! That's assuming that there is no outflow. If you include the outflow, the number would be far less.

If you look at the shorter edges, the same deposition rate exists, but on less snow. That doesn't adequately show the relationship between the overall deposition and outflow.

2% of 2000km is 40m.

That's averaging 4m of snowfall per year. Which, given snow is fluffy, is about 2m water equivalent per year. Which is twice what I would have expected.

Are you sure of your 2km average figure?

IBdaMann wrote:

Surface Detail wrote:The mass balance is actually falling, as evidenced by altimetry and gravimetric analysis.

Neither of which can accurately measure Greenland's ice mass to any useful degree. Especially when you have observations like Glacier Girl which point to a net ice mass balance increase of about 2% per decade.

Then there's Camp Century which ceased operations in 1966 and was abandoned in 1967. A bunch of the camp was simply left in place. It is now buried under ~36 meters of ice, ~7 meters per decade. Unlike Glacier Girl, this site was in northern Greenland, but was also somewhat close to the coast. The ice of this area of Greenland was/is estimated to be between 300-600m depth. If the ice depth was 350 meters then we have a 2% per decade increase in the net ice mass balance in that area as well. If the ice was more shallow then of course the net decadal increase is greater. If the ice is deeper then the net decadal increase is less than 2%.

Nonetheless, the camp is buried under 36 meters of net accumulated ice.

Aren't those empirical observations excellent? You can't argue with surveyor "boots on the ground" taking physical volumetric measurements, right? You can't argue with actual measurements of net ice accumulation, can you? Sure, you can argue that you want "accumulation" to mean something else, but that doesn't change the amount the Greenland net ice mass balance is increasing.



Have you, by any chance, stumbled upon any examples of any gas that radiates in violation of Planck's? Just wondering.


.

jwoodward48 wrote:

IBdaMann wrote:

Surface Detail wrote:The mass balance is actually falling, as evidenced by altimetry and gravimetric analysis.

Neither of which can accurately measure Greenland's ice mass to any useful degree. Especially when you have observations like Glacier Girl which point to a net ice mass balance increase of about 2% per decade.

Then there's Camp Century which ceased operations in 1966 and was abandoned in 1967. A bunch of the camp was simply left in place. It is now buried under ~36 meters of ice, ~7 meters per decade. Unlike Glacier Girl, this site was in northern Greenland, but was also somewhat close to the coast. The ice of this area of Greenland was/is estimated to be between 300-600m depth. If the ice depth was 350 meters then we have a 2% per decade increase in the net ice mass balance in that area as well. If the ice was more shallow then of course the net decadal increase is greater. If the ice is deeper then the net decadal increase is less than 2%.

Nonetheless, the camp is buried under 36 meters of net accumulated ice.

Aren't those empirical observations excellent? You can't argue with surveyor "boots on the ground" taking physical volumetric measurements, right? You can't argue with actual measurements of net ice accumulation, can you? Sure, you can argue that you want "accumulation" to mean something else, but that doesn't change the amount the Greenland net ice mass balance is increasing.



Have you, by any chance, stumbled upon any examples of any gas that radiates in violation of Planck's? Just wondering.


.

Suppose that we are studying a glacier. Let's call it the Verdean glacier, or V for short. V is currently in equilibrium - every year, about 0.7 meters of ice are added to the top (via 1.4 meters of snowfall), and an equivalent amount of ice is lost through calving and melting.

Let us suppose that in the year 1960, a camp called Millennium was established on V. It was abandoned in the year 1967. How much ice would we expect to find on top of it?

The answer is 34.3 meters, and that is in fact how much ice there is.

=============================================

Now, suppose that there is another glacier nearby. Let's call it the Wuskya glacier, or W for short. W is not in equilibrium. Every year, 0.7 meters of ice are added to the top, and twice the equivalent amount of ice is lost through calving and melting.

As it so happens, a camp called Decade was abandoned in the year 1967 on W. How much ice would we expect to find on top of it?

The answer is 34.3 meters, and that is in fact how much ice there is.

=============================================

Now suppose that there is another glacier nearby. Let's call it the Xyzzy glacier, or X for short. X is not in equilibrium. Every year, 0.7 meters of ice are added to the top, and none is lost.

As it so happens, a camp called Eon was abandoned in the year 1967 on X. How much ice would we expect to find on top of it?

The answer is 34.3 meters, and that is in fact how much ice there is.

=============================================

Questions:
1. Is there a difference between the three glaciers?
2. Is there a difference between the ice layers on top of the three camps?
3. Therefore, can we measure the ice mass balance from the ice on top of any object (save the ground)?

=============================================

As we can see, the independent variable (the ice lost every year) has no effect on the dependent variable (the depth of ice on top of a camp). Therefore, the null hypothesis has been upheld - no correlation.

jwoodward48 wrote:
What's wrong with it?

Why don't you calculate the depth of ice above each camp and see what you get?

jwoodward48 wrote:

IBdaMann wrote:

Surface Detail wrote:The mass balance is actually falling, as evidenced by altimetry and gravimetric analysis.

Neither of which can accurately measure Greenland's ice mass to any useful degree. Especially when you have observations like Glacier Girl which point to a net ice mass balance increase of about 2% per decade.

Then there's Camp Century which ceased operations in 1966 and was abandoned in 1967. A bunch of the camp was simply left in place. It is now buried under ~36 meters of ice, ~7 meters per decade. Unlike Glacier Girl, this site was in northern Greenland, but was also somewhat close to the coast. The ice of this area of Greenland was/is estimated to be between 300-600m depth. If the ice depth was 350 meters then we have a 2% per decade increase in the net ice mass balance in that area as well. If the ice was more shallow then of course the net decadal increase is greater. If the ice is deeper then the net decadal increase is less than 2%.

Nonetheless, the camp is buried under 36 meters of net accumulated ice.

Aren't those empirical observations excellent? You can't argue with surveyor "boots on the ground" taking physical volumetric measurements, right? You can't argue with actual measurements of net ice accumulation, can you? Sure, you can argue that you want "accumulation" to mean something else, but that doesn't change the amount the Greenland net ice mass balance is increasing.



Have you, by any chance, stumbled upon any examples of any gas that radiates in violation of Planck's? Just wondering.


.

Suppose that we are studying a glacier. Let's call it the Verdean glacier, or V for short. V is currently in equilibrium - every year, about 0.7 meters of ice are added to the top (via 1.4 meters of snowfall), and an equivalent amount of ice is lost through calving and melting.

Let us suppose that in the year 1960, a camp called Millennium was established on V. It was abandoned in the year 1967. How much ice would we expect to find on top of it?

The answer is 34.3 meters, and that is in fact how much ice there is.

=============================================

Now, suppose that there is another glacier nearby. Let's call it the Wuskya glacier, or W for short. W is not in equilibrium. Every year, 0.7 meters of ice are added to the top, and twice the equivalent amount of ice is lost through calving and melting.

As it so happens, a camp called Decade was abandoned in the year 1967 on W. How much ice would we expect to find on top of it?

The answer is 34.3 meters, and that is in fact how much ice there is.

=============================================

Now suppose that there is another glacier nearby. Let's call it the Xyzzy glacier, or X for short. X is not in equilibrium. Every year, 0.7 meters of ice are added to the top, and none is lost.

As it so happens, a camp called Eon was abandoned in the year 1967 on X. How much ice would we expect to find on top of it?

The answer is 34.3 meters, and that is in fact how much ice there is.

=============================================

Questions:
1. Is there a difference between the three glaciers?
2. Is there a difference between the ice layers on top of the three camps?
3. Therefore, can we measure the ice mass balance from the ice on top of any object (save the ground)?

=============================================

As we can see, the independent variable (the ice lost every year) has no effect on the dependent variable (the depth of ice on top of a camp). Therefore, the null hypothesis has been upheld - no correlation.

Tim the plumber wrote: So easy to check. Has the camp moved 20km?

IBdaMann wrote:

jwoodward48 wrote:
What's wrong with it?

Why don't you calculate the depth of ice above each camp and see what you get?

I don't get the same numbers you get.

Do you have any real world examples? I afforded two. Any example involving the real Greenland ice sheet would be more helpful in analyzing the Greenland ice sheet than your imaginary examples that necessarily work according to your Global Warming ideology which doesn't exactly line up with science.


.

jwoodward48 wrote:My imaginary examples that... must work because I can't accept them not working? That's an ad hominem. Fight the argument, not your opponent.

IBdaMann wrote:

jwoodward48 wrote:My imaginary examples that... must work because I can't accept them not working? That's an ad hominem. Fight the argument, not your opponent.

You're pretending to be insulted again just to avoid answering a straightforward question.

I'll ask again:

Do you have any real-world Greenland ice sheet examples as opposed to only hypothetical conceptualizations that work in your mind

according to your understanding of The Science?

jwoodward48 wrote: But! It does serve as a useful tool. For instance: Do V, W, and X have the same accumulation rate?

jwoodward48 wrote: So I will ask: is the amount of measured ice on top of a reference point dependent on:

1. The rate of deposition (minus the rate of sublimation).
2. The rate of overall accumulation.

IBdaMann wrote:

jwoodward48 wrote: But! It does serve as a useful tool. For instance: Do V, W, and X have the same accumulation rate?

Sure, and I enjoy theoreticals. I really do.

You just usually commit a foul when you do. If you are going to create a hypothetical thought experiment, you need to isolate the principle in question. You tend to mix various variables and seek an answer under fallacious circumstances. If extensive clarification is required then it's probably time to simplify the thought experiment.

jwoodward48 wrote: So I will ask: is the amount of measured ice on top of a reference point dependent on:

1. The rate of deposition (minus the rate of sublimation).
2. The rate of overall accumulation.

Fixed reference point or relative to the flow of the ice?

.

jwoodward48 wrote:A reference object that was laid down on the ice at a particular time, and remained fixed relative to the surrounding ice.

IBdaMann wrote:

jwoodward48 wrote:A reference object that was laid down on the ice at a particular time, and remained fixed relative to the surrounding ice.

Excellent. A relative point that moves with the flow of the ice.

First, let me give the bad news that's going to give Surface Detail a real headache. You obviously picked a practical, real scenario of ice accumulating atop ice that moves/flows, with ice breaking off of glaciers into the sea. The bottom line is that this scenario does a good job of concealing the fact that there is much more ice building up than warmizombies want to acknowledge.

For this explanation I need you to refresh your memory on "similar triangles."

Imagine a triangle wedge, e.g. a doorstop, with the small side pushed up against the wall, pointing away from the wall. We'll label this object "glacier" of volume "v."

Next, one decade later, you notice the doorstop is a similar triangle of a bit larger volume 1.02*v, and you push the doorstop one inch away from the wall. You now need to fill in that gap between the doorstop and the wall to complete the new similar triangle all the way up to the wall.

That gives you a new similar triangle that is much more than 2% more voluminous than the mere doorstop of a decade ago.

This is what is happening in Greenland, except that a bunch also breaks off into the ocean. How much? Greenland is not in ice equilibrium. Insufficient ice breaks off and the net ice mass balance of the Greenland ice sheet continues to grow.

So...your question appears to pertain to the growing-sliding doorstop model. Did I answer your question or shall we probe further?


.

jwoodward48 wrote:

IBdaMann wrote:

jwoodward48 wrote:My imaginary examples that... must work because I can't accept them not working? That's an ad hominem. Fight the argument, not your opponent.

You're pretending to be insulted again just to avoid answering a straightforward question.

I'm not insulted. I'm saying that your argument is fallacious.

I'll ask again:

Do you have any real-world Greenland ice sheet examples as opposed to only hypothetical conceptualizations that work in your mind

Ah, here's a decent argument I can understand.

according to your understanding of The Science?

Just leave that last bit off, and everything will be quite fine.

If there is an error in my scenario, please point it out.

The experimental stuff at the end was bad, I shouldn't have put it there. You're right. That proves nothing.

But! It does serve as a useful tool. For instance: Do V, W, and X have the same accumulation rate?

So I will ask: is the amount of measured ice on top of a reference point dependent on:

1. The rate of deposition (minus the rate of sublimation).
2. The rate of overall accumulation.

My glaciers are not necessary to prove this point, but they can help by giving an imaginary, specific example of particular things.

Tim the plumber wrote:

When they measure the level of ice on top of last year's ice, then that is last year's ice after a summer, after all the melting that it is ever going to get untill it is exposed again.

So given that they say that each year there is a 1m accumulation of ice, water equivalent, that means that they are allowing for the melting already. The layers of ice being 1m w.e. appart.

That there is a tiny amount of ice flowing down the glaciers will not change this substantially. To reach an equilibrium there would have to be 45 Mississippis flowing out of Greenland during the brief summer when all the ice melting and ice calving happens.

jwoodward48 wrote:Then what's the "sliding" part?

jwoodward48 wrote: The 1.02 increase in volume is the deposition, right?

IBdaMann wrote:

jwoodward48 wrote:Then what's the "sliding" part?

The ice is moving. The ice is flowing.

jwoodward48 wrote: The 1.02 increase in volume is the deposition, right?

It is the net ice accumulation over the relative point that moves with the flowing ice, per your question. The doorstop wedge is the answer to your question. That's what is going on...once you fill in the gap behind the wedge.

.

jwoodward48 wrote:But when the ice flows, ice doesn't magically appear behind it.

IBdaMann wrote:

jwoodward48 wrote:But when the ice flows, ice doesn't magically appear behind it.

Exactly. There is certainly ice filling in behind it and it isn't by magic.

That is some serious continuous ice accumulation going on in Greenland.