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grixm

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Re: Freeform season chatter and light commentary
« Reply #450 on: August 09, 2019, 08:44:46 AM »
Eye of a hurricane? No, this strange looking cloud is located in Baffin Bay!


binntho

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Re: Freeform season chatter and light commentary
« Reply #451 on: August 09, 2019, 09:01:55 AM »
Aliens?
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

dnem

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Re: Freeform season chatter and light commentary
« Reply #452 on: August 09, 2019, 05:20:41 PM »
Killian wrote on the 2012 vs 2019 thread:

"You mean 7 years of data isn't enough to predict weather? That would b a wild assertion given the short-term nature of weather forecasting. I'm assuming you mean seven years of weather is not enough to forecast climate?

Either way, this would be incorrect. First, in any given year, the majore forcing for the ASI minima is weather, but overall the climatic changes are setting the context. I would suggest that climate forcing is changing so fast and at such magnitude, it is having noticeable yearly effects. Still, most of the year-to-year differences will be weather. Climate is found in the trends."

Sorry Killian, this statement makes no sense. Of course seven years is not enough to generate climatological data from which to predict the weather. Not even close.  No idea what you're trying to say.  The issue at hand was about the statistical validity of tossing out 2012 as an outlier when trying to think about what may be to come for the arctic.  The arctic is a rapidly transitioning system and there is no valid way to make predictions about what the next few years may bring.  We can look back at the years since 2007 and make some informed guesses.  That's about it.

Just look at Zach's heat chart of monthly ranks.  After two cold, cloudy Julys folks were ready to declare a new trend.  Not so much.

gerontocrat

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Re: Freeform season chatter and light commentary
« Reply #453 on: August 12, 2019, 08:51:46 PM »
There has been comment here and there about how the very high SSTs might delay the onset of freezing, both timing and speed.

My guess is there is a correlation between accumulated AWP and SSTs. Is there a correlation beteen AWP and SSTs and the beginning & speed of the freezing season? I had a quick look.

- couldn't find Arctic SST anomaly maps for late Arctic Summer over recent years,
- but we have Tealight's AWP anomaly graphs. 2012 and 2016 are the years with abnormally high cumulative AWP anomaly, 2016 being the highest.

So also tweaked a graph to show Arctic Sea Ice Extent August to December, highlighting 2012  and 2016. In neither year was there a stretching out of the minimum. Rather the reverse. But 2016 does show really slow refreeze from late October to early December.

2019 looks like being a new record year for Cumulative AWP anomaly. So if there is an effect, when will it take effect and how long and how significant will it be?



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DrTskoul

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Re: Freeform season chatter and light commentary
« Reply #454 on: August 12, 2019, 09:19:31 PM »
If only one could calculate the "actualized" AWP...

FishOutofWater

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Re: Freeform season chatter and light commentary
« Reply #455 on: August 12, 2019, 09:28:18 PM »
AWP and SST anomalies should directly correlate and it would be disturbing if there was no correlation. Obviously, there are other factors related to winds, currents and initial conditions, but the correlation looks strong this year. If that extra heat doesn't delay freezing, there's going to be a lot of heat stored below the surface of the ice. It a good bet we'll see a combination of the two.


philopek

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Re: Freeform season chatter and light commentary
« Reply #456 on: August 12, 2019, 09:33:35 PM »
In neither year was there a stretching out of the minimum. Rather the reverse. But 2016 does

Great job as always, thanks.

As to the "reverse" part, that makes totally sense since the less ice remains, the more retreated, speak north, is the ice edge and therefore some of the open water will be exposed to really cold conditions way earlier than farther south.

In addition to that, the last stretch of melted ice, and the faster it melted the more is this the case, must have a significantly lower salinity due to the only recently melted ice that is less saline and recently melted regions are most probably a bit cooler SST wise than the stretches that melted earlier and had time to mix, increase salinity and eventually got some sunlight.

Those two factors and perhaps a few others make it somehow logical that the melt onset is a bit earlier and also covering a wider area a bit quicker to begin with. A later slow down like in 2016 makes also sense since the excess systemic (global) warmth with warmer winds and warmer ocean currents reaching farther north would  explain such a slowdown to quite some extent.

« Last Edit: August 13, 2019, 11:21:10 AM by philopek »

oren

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Re: Freeform season chatter and light commentary
« Reply #457 on: August 12, 2019, 10:57:31 PM »
What philopek said. 2016 had a quick initial refreeze due to there being open water very far north and in the middle of the pack. Later it had a terrible refreeze, especially in the Chukchi.

In addition, check out 2018's strange behavior in October in the CAB. After being a mediocre year in mid-Sept, it broke records in mid-Oct.
« Last Edit: August 13, 2019, 06:09:04 AM by oren »

binntho

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Re: Freeform season chatter and light commentary
« Reply #458 on: August 13, 2019, 06:00:14 AM »
Great job Gerontocrat! And I agree with what philopek said.
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

HapHazard

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Re: Freeform season chatter and light commentary
« Reply #459 on: August 13, 2019, 11:07:17 AM »
Yep, philopek nailed it.
If I call you out but go no further, the reason is Brandolini's law.

be cause

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Re: Freeform season chatter and light commentary
« Reply #460 on: August 13, 2019, 12:43:17 PM »
No worldview images today .. rather unusual .. I normally have my first daily look mid-morning . This is my first day without .. suffering withdrawl .. b.c.
Conflict is the root of all evil , for being blind it does not see whom it attacks . Yet it always attacks the Son Of God , and the Son of God is you .

philopek

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Re: Freeform season chatter and light commentary
« Reply #461 on: August 13, 2019, 03:15:11 PM »
No worldview images today .. rather unusual .. I normally have my first daily look mid-morning . This is my first day without .. suffering withdrawl .. b.c.

Rammb's Natural Colors are working again FWIW for your needs, there are interesting news
i.e. McLure and more ;)

CalamityCountdown

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Re: Freeform season chatter and light commentary
« Reply #462 on: August 15, 2019, 01:13:22 AM »
This is probably a silly analogy, but in comparing 2019 to 2012, the two upcoming dates of century drops in 2012 remind me of an elite marathoner that throws 4:30 miles at his (or her) opponent to try an shake them off. If 2019 extent stays close to 2012 extent through the two upcoming centuries, this melt season could eventually end up with more days at satellite era record lows. Scary times.   (Chart credit: Gerontocrat)

DrTskoul

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Re: Freeform season chatter and light commentary
« Reply #463 on: August 15, 2019, 01:16:28 AM »
2019, still hangs on... let's see how much steam is left...

bluice

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Re: Freeform season chatter and light commentary
« Reply #464 on: August 15, 2019, 09:38:27 AM »
Not much has changed since June regarding the minimum extent record. 2019 is going for the 2nd place, but has a small chance of beating 2012's record.

be cause

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Re: Freeform season chatter and light commentary
« Reply #465 on: August 15, 2019, 11:00:28 AM »
.. or as I would say .. not much has changed since March .. b.c.
Conflict is the root of all evil , for being blind it does not see whom it attacks . Yet it always attacks the Son Of God , and the Son of God is you .

HapHazard

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Re: Freeform season chatter and light commentary
« Reply #466 on: August 15, 2019, 07:19:57 PM »
.. or as I would say .. not much has changed since March .. b.c.
Just keeps marching on.  ;D
If I call you out but go no further, the reason is Brandolini's law.

pearscot

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Re: Freeform season chatter and light commentary
« Reply #467 on: August 15, 2019, 07:29:03 PM »
No worldview images today .. rather unusual .. I normally have my first daily look mid-morning . This is my first day without .. suffering withdrawl .. b.c.

SAME HERE!! Everything is down at the moment and it's killing me. The barrow ice cam hasn't updated since 8/1 and even this one isn't updated:

https://www.foto-webcam.eu/webcam/freya1/

If I actually have to work at work today I'm going to be quite unhappy.
pls!

DrTskoul

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Re: Freeform season chatter and light commentary
« Reply #468 on: August 15, 2019, 08:18:01 PM »
... oh the shakes and the chills...  ;D ;D

sark

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Re: Freeform season chatter and light commentary
« Reply #469 on: August 16, 2019, 07:07:35 AM »
What's the wave called that precesses about the North Pole about once every 7 days?

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Re: Freeform season chatter and light commentary
« Reply #470 on: August 18, 2019, 09:03:33 PM »
But entanglement is immediate - happens totally simultaneously, with information travelling at infinitely more than the speed of light.

As far as I understand it, entanglement does not involve propagation but simply uncovering a pre-existing state. But I'm no quantum physicist.

The reason that I mention water waves is that presumably that's how melt water is moved around the oceans.

Edit: This is relevant, showing a correlation of increased local/regional sea-level with increased river discharge: https://doi.org/10.1073/pnas.1805428115 .

sark

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Re: Freeform season chatter and light commentary
« Reply #471 on: August 19, 2019, 03:27:47 AM »
This here is that 6000 thickness thing, anomaly, month by month.  rolling 5 year composite average.

the first 7 months have a 2019, the rest waiting.

If Aug-Sept 19 don't settle down, next chance is December for a +AO?

sark

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Re: Freeform season chatter and light commentary
« Reply #472 on: August 19, 2019, 06:35:42 AM »
What is this retrograde high pressure wave on a 5-8 day cycle?  (try posting mp4)

oren

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Re: Freeform season chatter and light commentary
« Reply #473 on: August 19, 2019, 07:03:34 AM »
A. Greenland indeed has a gravitational pull.  It affects water levels permanently around Greenland.
B. If Greenland ice disappeared, water levels would drop by tens of meters nearby, and the effect will be felt in a large area. Sounds science fiction but true.
C. Ireland tides therefore can rise due to many factors, but the factor that absolutely cannot cause them to rise is Greenland melt. Counterintuitive but true.
D. Greenland pulls not only ice, but also water. The water is "inclined" towards Greenland. Therefore imagining that this causes ice to flow over static water and stick to Greenland is wrong.
E. Kitchen ice cubes stick to each other because first they melt at the edge, then they touch, then the edges freeze together . And edges must be large comapred to the cube size. Only when all this happens will ice stick to its neighbor. This does not happen with ice floes in the Arctic in summer.
F. The place for raising such things is not the melting season thread, but the questions thread.

Am I the only one noticing the higher tides of late? Today in Ireland the tide was the highest Ive ever seen on the beach I went to in Sligo. 3 weeks ago I went to another beach and noticed some of the road had been taken by the sea. Is this related to the gigaton melting in Greenland and the Arctic? Is it already happening?

My theory is that Greenlands mass pulls the ice towards it.

I like your theory, it makes a lot of sense.

This is an article about the gravitational pull of Greenland. I also included a NASA video that shows the lowering of sea levels around Greenland as the ice cap melts, and the gravitational pull weakens. This could also maybe explain why sea levels in Ireland are going up?

Gravitational Attraction of Ice Sheets on the Sea
http://sealevelstudy.org/sea-change-science/whats-in-a-number/attractive-ice-sheets
« Last Edit: August 19, 2019, 07:24:11 AM by oren »

binntho

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Re: Freeform season chatter and light commentary
« Reply #474 on: August 19, 2019, 07:20:10 AM »
But entanglement is immediate - happens totally simultaneously, with information travelling at infinitely more than the speed of light.
As far as I understand it, entanglement does not involve propagation but simply uncovering a pre-existing state. But I'm no quantum physicist.

Well neither am I - but according to Niels Bohr's view of how quantum works, there are is no "uncovering of pre-existing states" - that's almost what is meant by "quantum" in a physics context: A quanta is the very smallest "thingie" there can be, so there is no possibility of anything else being hidden or waiting to be uncovered inside.

And entangled pairs of particles (photons, electrons etc.) will change instantaneously when one of them is changed. This has been tested and the information is exchanged at a speed much higher than the speed of light. https://newatlas.com/quantum-entanglement-speed-10000-faster-light/26587/

As for gravity, the general consensus seems to be that it travels at the speed of light - a gravitational wave from a spiralling neutron star can be measured at almost the same time as the gamma rays hit.

Quantum physics is very interesting in that they allow for (and have repeatedly been tested for) things like instantaneousness, true randomness, and cause-less events. All things that do not exist outside the realms of quantum physics (as far as we know!)
because a thing is eloquently expressed it should not be taken to be as necessarily true
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nanning

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Re: Freeform season chatter and light commentary
« Reply #475 on: August 19, 2019, 11:03:47 AM »
<snip>But entanglement is immediate - happens totally simultaneously, with information travelling at infinitely more than the speed of light.

Causality is fundamental!
Information cannot move faster than lightspeed. Otherwise nasty paradoxes arise.

@petm You are correct but it does not uncover a pre-existing state. Observation (measurement) of one of the particles collapses the entanglement wavefunction. The entangled particle far away is now no longer entangled and has the same state as the observed one. If you take a peek at one, you simultaneously take a peek at the other(s).
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binntho

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Re: Freeform season chatter and light commentary
« Reply #476 on: August 19, 2019, 11:15:18 AM »
<snip>But entanglement is immediate - happens totally simultaneously, with information travelling at infinitely more than the speed of light.

Causality is fundamental!
Information cannot move faster than lightspeed. Otherwise nasty paradoxes arise.

Well, not in the quntum world!

Quantum events, such as the decay of a radioactive atom, happens without any cause. There is absolutely no way to predict the decay (neither theoretically or practically), therefore there is absolutely no way that there could be any causality behind the event of an atom decaying.

In other words, an event without a cause!

The speed of information flow in the Quantum world has apparently been measured at having a lower limit of 10.000 times the speed of light (https://www.extremetech.com/extreme/150207-chinese-physicists-measure-speed-of-einsteins-spooky-action-at-a-distance-at-least-10000-times-faster-than-light)
because a thing is eloquently expressed it should not be taken to be as necessarily true
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binntho

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Re: Freeform season chatter and light commentary
« Reply #477 on: August 19, 2019, 11:19:02 AM »
@petm You are correct but it does not uncover a pre-existing state. Observation (measurement) of one of the particles collapses the entanglement wavefunction. The entangled particle far away is now no longer entangled and has the same state as the observed one. If you take a peek at one, you simultaneously take a peek at the other(s).
But since the outcome of the collapse is non-predictable, this becomes a good example of information travelling instantaneosly, without predetermined correlation.

(The postcard example is often used to describe instantaneous information travel with predetermined correlation. If I send two postcars, one with a cat to nanning and one with a dog to petm, then the first one to look at his card will know instantaneously what the other has got).
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

gandul

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Re: Freeform season chatter and light commentary
« Reply #478 on: August 19, 2019, 02:16:39 PM »
Found no "Coriolis" mention in this page. Nor "Transpolar"
Fresh water is up (salty water down)
Fresh water and ice run toward the Fram. Why? Because of two reasons:
 - Dominating transpolar drift pushes ice and water against CAA/Greenland.
 - Fram is the greatest outlet for this pushed water/ice at the surface. (How different climate would be without the CAA in the middle. Ice would escape so soon. Blue ocean. BOOM.)
Then Coriolis force looks toward Greenland for ice/water wanting to escape the Arctic thru Fram. The current bends around Greenland at Fram thanks to Coriolis force too.

Therefore we have two major "attractors" that force ice/cold fresh water to stick to Greenland: Transpolar winds/drift and Coriolis force.

None of it is gravity.

As an example of the nonsense of this gravitational pull theory, this is Kane Basin (Nares Strait outlet). At the right, Greenland. At the left, Elles-whatever, another island with much less gravitational pull. These are from June 4 to June 9, I think.

When the Nares export is really going, the ice and the water from the Arctic tend to stick toward their right (Elles-whatever), staying AWAY from the Greenland side.

Anti-gravity?
« Last Edit: August 19, 2019, 02:49:09 PM by gandul »

Neven

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Re: Freeform season chatter and light commentary
« Reply #479 on: August 19, 2019, 03:55:46 PM »
Comment from new member was in the wrong thread:

This is an article about the gravitational pull of Greenland. I also included a NASA video that shows the lowering of sea levels around Greenland as the ice cap melts, and the gravitational pull weakens. This could also maybe explain why sea levels in Ireland are going up?

Gravitational Attraction of Ice Sheets on the Sea
http://sealevelstudy.org/sea-change-science/whats-in-a-number/attractive-ice-sheets

We're getting OT again but I say greenland is raising and not the water is lowering, i discussed this before over many years and never reached consensus. Those who believe some theories and papers as sacrosanct cannot be convinced and the same with the other side.

Either way thanks for the input, never wrong to document a point.
Hi philopek. I agree that sea level changes because of the gravity of Greenland is totally OT, but the reason I posted this was to prove that the Greenland ice sheet does have a large gravitational pull on things. And so the point I'm making is that it's not unreasonable to think that the Greenland ice sheet is "pulling" on ice that's floating on the arctic ocean. It's like 2 ice cubes sticking together. This would explain why MYI can always be found closest to the North American coast. I believe that's because the largest ice mass is located on the pole. And the pole is located closest to Greenland. So I can't imagine that these two ice massas wouldn't have a pull on eachother.

A counterclaim to my theory is that water has more mass than ice. That's why ice floats, right? And so why would Greenland attract the ice instead of the more massive water?

I'm not sure this is entirely OT. It probably is a little, but it belongs in the melting season I think because my theory does have an effect on ice movement. But I'd be happy to discuss this somewhere else.

I know this is OT, but its also just so wrong that it needs to be corrected in a science forum. One water is more dense than ice, if you take a kilogram of water and freeze it, it is still 1 kg of frozen water it did not lose any mass. That is why it floats. Second, the melting of Greenland's ice sheet this year alone will probably raise sea level by ~ 2mm (and that is probably generous as its rising an average of 3mm per year https://climate.nasa.gov/vital-signs/sea-level/)  it is definitely in no way shape or form the cause of a high tide in Ireland. And third, there are multiple reasons that the sea ice edge sticks to Greenland , the "Gravitational effect of Greenland" is at the bottom of that list.

Sorry, but I don't think people should read through this forum and learn just bad basic science and physics. End OT.
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oren

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Re: Freeform season chatter and light commentary
« Reply #480 on: August 19, 2019, 04:17:13 PM »
Welcome tolfer10, and you are absolutely correct in your response.
It is quite a challenge to handle comments that are OT and scientifically wrong - to shut up is bad, to continue the OT derailing is bad too.

Note: thanks also to gandul for mentioning Coriolis and Transpolar drift.

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Re: Freeform season chatter and light commentary
« Reply #481 on: August 19, 2019, 04:21:45 PM »
A. Greenland indeed has a gravitational pull.  It affects water levels permanently around Greenland.
B. If Greenland ice disappeared, water levels would drop by tens of meters nearby, and the effect will be felt in a large area. Sounds science fiction but true.
Do you have an actual scientific reference to back this up?

As a back of the envelope calculation, taking the mass of the entire Greenland ice sheet and assuming a best case distance from the centre of mass of about 750km at the Greenland shore, the gravitational attraction comes by at about 11 orders of magnitude less than the gravitational attraction of the earth and about 5 orders of magnitude less than the gravitational pull of the moon.

I would be very interested in seeing how this could translate to tens of meters of water column displacement, considering that the tidal amplitude caused by the moon is only about 0.5 meters, and is amplified only due to other variables.
« Last Edit: August 19, 2019, 04:30:30 PM by stjuuv »

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Re: Freeform season chatter and light commentary
« Reply #482 on: August 19, 2019, 04:35:32 PM »
A. Greenland indeed has a gravitational pull.  It affects water levels permanently around Greenland.
B. If Greenland ice disappeared, water levels would drop by tens of meters nearby, and the effect will be felt in a large area. Sounds science fiction but true.
C. Ireland tides therefore can rise due to many factors, but the factor that absolutely cannot cause them to rise is Greenland melt. Counterintuitive but true.
D. Greenland pulls not only ice, but also water. The water is "inclined" towards Greenland. Therefore imagining that this causes ice to flow over static water and stick to Greenland is wrong.
Thank you for explaining this so clearly Oren. That makes absolute sense to me what you are saying. Thanks for clearing that up for me! It's always good to learn something new, like this;
Quote
Kitchen ice cubes stick to each other because first they melt at the edge, then they touch, then the edges freeze together . And edges must be large comapred to the cube size. Only when all this happens will ice stick to its neighbor. This does not happen with ice floes in the Arctic in summer.
I guess I'm at the right place to learn everything there is to know about ice.  ;D

Quote
F. The place for raising such things is not the melting season thread, but the questions thread.

My apology. I thought it was relevant.
90% of the world is religious, but somehow "love thy neighbour" became "fuck thy neighbours", if they don't agree with your point of view.

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Re: Freeform season chatter and light commentary
« Reply #483 on: August 19, 2019, 04:44:44 PM »


As a back of the envelope calculation, taking the mass of the entire Greenland ice sheet and assuming a best case distance from the centre of mass of about 750km at the Greenland shore, the gravitational attraction comes by at about 11 orders of magnitude less than the gravitational attraction of the earth and about 5 orders of magnitude less than the gravitational pull of the moon.

Your calculations are wrong. The mass of the earth is 6e12 GT, the mass of the Greenland ice is 3e6 GT,  a ratio of only 2 million. Also, the ice is closer than the centre of the Earth by an order of magnitude, so the gravity is only different by a factor of ~20,000.
A slope of 1 in 20,000 over 2000Km amounts to a rise of 100 metres.

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Re: Freeform season chatter and light commentary
« Reply #484 on: August 19, 2019, 04:49:27 PM »
I know this is OT, but its also just so wrong that it needs to be corrected in a science forum. One water is more dense than ice, if you take a kilogram of water and freeze it, it is still 1 kg of frozen water it did not lose any mass. That is why it floats.
Sorry, but I don't think people should read through this forum and learn just bad basic science and physics. End OT.
I guess I'm a little rusty on my physics lessons, so my apology if this is a stupid question, but isn't mass calculated by volume? 1m3 of water weighs more that 1m3 of ice, so doesn't that mean that the mass of ice is lower than the mass of water?
90% of the world is religious, but somehow "love thy neighbour" became "fuck thy neighbours", if they don't agree with your point of view.

WTF happened?

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Re: Freeform season chatter and light commentary
« Reply #485 on: August 19, 2019, 05:01:03 PM »


As a back of the envelope calculation, taking the mass of the entire Greenland ice sheet and assuming a best case distance from the centre of mass of about 750km at the Greenland shore, the gravitational attraction comes by at about 11 orders of magnitude less than the gravitational attraction of the earth and about 5 orders of magnitude less than the gravitational pull of the moon.

Your calculations are wrong. The mass of the earth is 6e12 GT, the mass of the Greenland ice is 3e6 GT,  a ratio of only 2 million. Also, the ice is closer than the centre of the Earth by an order of magnitude, so the gravity is only different by a factor of ~20,000.
A slope of 1 in 20,000 over 2000Km amounts to a rise of 100 metres.

Thanks Pikaia.


Are you saying the current level of the sea by Greenland would drop by 100m if the ice were removed?  (Not melted, just removed).

Freegrass

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Re: Freeform season chatter and light commentary
« Reply #486 on: August 19, 2019, 05:09:56 PM »
If all the ice of Greenland would be removed, the land would rise, and the sea level would drop. But I wouldn't know by how much.
90% of the world is religious, but somehow "love thy neighbour" became "fuck thy neighbours", if they don't agree with your point of view.

WTF happened?

binntho

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Re: Freeform season chatter and light commentary
« Reply #487 on: August 19, 2019, 05:11:56 PM »
I know this is OT, but its also just so wrong that it needs to be corrected in a science forum. One water is more dense than ice, if you take a kilogram of water and freeze it, it is still 1 kg of frozen water it did not lose any mass. That is why it floats.
Sorry, but I don't think people should read through this forum and learn just bad basic science and physics. End OT.
I guess I'm a little rusty on my physics lessons, so my apology if this is a stupid question, but isn't mass calculated by volume? 1m3 of water weighs more that 1m3 of ice, so doesn't that mean that the mass of ice is lower than the mass of water?
You are thinking of specific mass, which is indeed a product of mass and volume.

The mass of an object is only partly related to the weight of the object (weight being a product of gravity and mass), but given the same gravitational pull, 1kg of floating water will still have the same weight and the same mass after it freezes (~9.81 N in both cases).
because a thing is eloquently expressed it should not be taken to be as necessarily true
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binntho

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Re: Freeform season chatter and light commentary
« Reply #488 on: August 19, 2019, 05:15:43 PM »
If all the ice of Greenland would be removed, the land would rise, and the sea level would drop. But I wouldn't know by how much.

Isostatic movement would cause the Greenland landmass to rise if the ice was removed. This however will not cause sea levels to drop (except of course locally). Another effect is that the surrounding seafloor (and to a much lesser extent the continents) will sink as the Greenland landmass rises.

Local sea level drops are still ongoing in Scotland, Northern Scandinavia and I beleieve in Canada and Alaska, the land still being on the up and up after the last major glaciation.
because a thing is eloquently expressed it should not be taken to be as necessarily true
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pikaia

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Re: Freeform season chatter and light commentary
« Reply #489 on: August 19, 2019, 05:24:16 PM »

Are you saying the current level of the sea by Greenland would drop by 100m if the ice were removed?  (Not melted, just removed).

That is the figure that I have seen, presumably from a more precise calculation.

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Re: Freeform season chatter and light commentary
« Reply #490 on: August 19, 2019, 05:26:45 PM »
Sorry to interrupt the 'meaningless chatter'.  8)
One last response to binntho: Please be aware of the context of quantum.
And the correspondence principle.

As you were  :)
"It is preoccupation with possessions, more than anything else, that prevents us from living freely and nobly" - Bertrand Russell
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Why do you keep accumulating stuff?

Freegrass

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Re: Freeform season chatter and light commentary
« Reply #491 on: August 19, 2019, 05:29:02 PM »
Isostatic movement would cause the Greenland landmass to rise if the ice was removed. This however will not cause sea levels to drop (except of course locally).
I meant locally of course. Global sea levels would rise by 7 meter I believe if the entire Greenland ice sheet would melt?

Quote
Local sea level drops are still ongoing in Scotland, Northern Scandinavia and I beleieve in Canada and Alaska, the land still being on the up and up after the last major glaciation.
Wow. I didn't know that.

I have another theory I might as well put on the table now.

With all the ice melting in the world, from glaciers to ice sheets, and the water levels rising in the oceans, one could say that the forces on the earth's crust are changing. I believe that these changing forces on the earth's crust will cause more earthquakes and volcanic eruptions. Is that a crazy theory, or could there be some truth in this?
« Last Edit: August 19, 2019, 05:41:44 PM by Freegrass »
90% of the world is religious, but somehow "love thy neighbour" became "fuck thy neighbours", if they don't agree with your point of view.

WTF happened?

binntho

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Re: Freeform season chatter and light commentary
« Reply #492 on: August 19, 2019, 05:53:53 PM »
Sorry to interrupt the 'meaningless chatter'.  8)
One last response to binntho: Please be aware of the context of quantum.
And the correspondence principle.

As you were  :)
Interrupt at will! I'm not sure what you mean by "context of quantum", but Niels Bohr (who was also the author of the Correspondence principle) was very clear on stating that a quanta is the smallest there can be.

So a quanta (or quantum state) cannot contain anything hidden, any extra capabilities or physical laws. When a quantum wave collapses, there is no predicting the outcome because there is no causal link between the collapse, or anything that caused the collapse, and the specific outcome.

So if two entangled particles change because one of them is measured (the waveform collapses), the other has to "learn" which state the first one collapsed to. This is information, and it travels instantaneously (theoretically) or at least 10.000 times faster than light (as measured).

The world at the time of the Big Bang was governed by quantum physics, so if we follow that logic, the world was created without a primal cause (it was simply a random collapse of a wave function).
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

dnem

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Re: Freeform season chatter and light commentary
« Reply #493 on: August 19, 2019, 06:06:57 PM »
With all the ice melting in the world, from glaciers to ice sheets, and the water levels rising in the oceans, one could say that the forces on the earth's crust are changing. I believe that these changing forces on the earth's crust will cause more earthquakes and volcanic eruptions. Is that a crazy theory, or could there be some truth in this?

Not crazy at all. Tons have been written on this, e.g.
https://www.smithsonianmag.com/science-nature/melting-glaciers-are-wreaking-havoc-earths-crust-180960226/

petm

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Re: Freeform season chatter and light commentary
« Reply #494 on: August 19, 2019, 06:16:37 PM »
But entanglement is immediate - happens totally simultaneously, with information travelling at infinitely more than the speed of light.
As far as I understand it, entanglement does not involve propagation but simply uncovering a pre-existing state. But I'm no quantum physicist.
And entangled pairs of particles (photons, electrons etc.) will change instantaneously when one of them is changed. This has been tested and the information is exchanged at a speed much higher than the speed of light. https://newatlas.com/quantum-entanglement-speed-10000-faster-light/26587/

On the other hand:
Quote
However, the far more likely option is that relativity is correct. In that case, the strong ban on faster-than-light communication would rule out the possibility of faster-than-light transfer of information encoded in hidden variables, and force us to deal with nonlocality. Once again, it would seem that local realism and relativity are incompatible notions in the quantum world.
https://arstechnica.com/science/2012/10/quantum-entanglement-shows-that-reality-cant-be-local/

It seems like there is debate over this, at least if these news reports are accurate. Quantum physics is way outside my realm of understanding (aside from the popular science aspects) and can perhaps only be "understood" using specialized advanced mathematics, not human intuition.

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Re: Freeform season chatter and light commentary
« Reply #495 on: August 19, 2019, 06:20:13 PM »
As a back of the envelope calculation, taking the mass of the entire Greenland ice sheet and assuming a best case distance from the centre of mass of about 750km at the Greenland shore, the gravitational attraction comes by at about 11 orders of magnitude less than the gravitational attraction of the earth and about 5 orders of magnitude less than the gravitational pull of the moon.
Your calculations are wrong. The mass of the earth is 6e12 GT, the mass of the Greenland ice is 3e6 GT,  a ratio of only 2 million. Also, the ice is closer than the centre of the Earth by an order of magnitude, so the gravity is only different by a factor of ~20,000.
A slope of 1 in 20,000 over 2000Km amounts to a rise of 100 metres.
I stand corrected, thank you!

However, I would still appreciate any references  :)

binntho

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Re: Freeform season chatter and light commentary
« Reply #496 on: August 19, 2019, 06:22:51 PM »
It seems like there is debate over this, at least if these news reports are accurate. Quantum physics is way outside my realm of understanding (aside from the popular science aspects) and can perhaps only be "understood" using specialized advanced mathematics, not human intuition.

Well put. ;D
because a thing is eloquently expressed it should not be taken to be as necessarily true
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petm

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Re: Freeform season chatter and light commentary
« Reply #497 on: August 19, 2019, 06:31:58 PM »
A. Greenland indeed has a gravitational pull.  It affects water levels permanently around Greenland.
B. If Greenland ice disappeared, water levels would drop by tens of meters nearby, and the effect will be felt in a large area. Sounds science fiction but true.
Do you have an actual scientific reference to back this up?

Quote
When Greenland melts, places as far away as Norway and Scotland could actually see the sea level fall by as much as 50 meters. “But you pay the price somewhere,” Mitrovica said. In the Southern Hemisphere, you get more [sea level rise] than you bargained for.” The same counterbalancing effect holds for the West Antarctic Ice Sheet. If it were to collapse, the seas would rise the highest near Washington, D.C., and Northern California.
https://www.sciencemag.org/news/2016/02/how-melting-ice-sheet-could-actually-lower-sea-level-some-places

binntho

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Re: Freeform season chatter and light commentary
« Reply #498 on: August 19, 2019, 06:34:41 PM »
As a back of the envelope calculation, taking the mass of the entire Greenland ice sheet and assuming a best case distance from the centre of mass of about 750km at the Greenland shore, the gravitational attraction comes by at about 11 orders of magnitude less than the gravitational attraction of the earth and about 5 orders of magnitude less than the gravitational pull of the moon.
Your calculations are wrong. The mass of the earth is 6e12 GT, the mass of the Greenland ice is 3e6 GT,  a ratio of only 2 million. Also, the ice is closer than the centre of the Earth by an order of magnitude, so the gravity is only different by a factor of ~20,000.
A slope of 1 in 20,000 over 2000Km amounts to a rise of 100 metres.
I stand corrected, thank you!

However, I would still appreciate any references  :)

https://core.ac.uk/download/pdf/25988300.pdf

I found this paper, doesn't really answer the calculations, but seems to indicate that sea level is falling by up to 0.8 mm/year close to Greenland with ice loss at 165Gt/year.

The same ice loss causes rises of up to 0.8 in other areas of the oceans, particularly in the Southern and Pacific oceans.

So if the entire ice sheet were to melt, a global 7 m sea level rise, but a localized 7 m sea level fall closest to Greenland?

Here's another short article with a fantastic picture (albeit not of an ice sheet), https://www.sciencemag.org/news/2016/02/how-melting-ice-sheet-could-actually-lower-sea-level-some-places

Quote
Right now, that ice is a huge weight pushing down Earth’s crust in and around Greenland. So when it’s gone, that land will pop up. An intact ice sheet also has a noticeable gravitational pull, which attracts water to the region. No ice means that water will rush away. Both of those effects actually add up to lower sea levels in the area right around the former ice sheet, Mitrovica said. When Greenland melts, places as far away as Norway and Scotland could actually see the sea level fall by as much as 50 meters.

Sounds pretty far-fetched to me! But here is another eminent scientist:

Quote from: http://nautil.us/issue/62/systems/why-our-intuition-about-sea_level-rise-is-wrong-rp
So if the Greenland ice sheet were to catastrophically collapse tomorrow, the sea level in Iceland, Newfoundland, Sweden, Norway—all within this 2,000 kilometer radius of the Greenland ice sheet—would fall. It might have a 30 to 50 meter drop at the shore of Greenland.
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binntho

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Re: Freeform season chatter and light commentary
« Reply #499 on: August 19, 2019, 06:35:08 PM »
Crossposting with petm ...  8)
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6