Eric Worrall writes:
Based on the current rate of Antarctic ice growth, how long until an ice bridge forms between South America and Antarctica?
Lets start with a simplification – if you squint hard Antarctica is a circle. Antarctica, according to Wikipedia, is 14 million square miles. Sea ice this year covered 20 million square miles. So what is the radius of a 34 million square mile circle?
area = PI x radius ^ 2
so
(34,000,000 / PI) ^ 0.5 = 3289 miles
So the radius of our “circular” Antarctica is approximately 3289 miles.
According to Wikipedia, the distance between Antarctica and South America is 500 miles. http://en.wikipedia.org/wiki/Drake_Passage So we need to calculate, what is the perfectly circular volume of sea ice required to increase the radius by another 500 miles?
Using our area calculation,
Area = PI x radius ^ 2
Area = PI * (3289 + 500) ^ 2 = 45 million square miles.
Since 34 million square miles (the land area of Antarctica + sea ice) is already taken, to increase the radius of Antarctica enough to close the gap, ice growth needs to fill in another 11 million square miles.
At say 300,000 square miles growth per year (lets not forget, this year busted records by 600,000 square miles), and via my drastically simplified calculation, we could expect Antarctic ice to close the Drake passage in 36 years – by 2050.
Interestingly 2055 – 2060 is the peak of the coming Little Ice Age event predicted by Dr. Khabibullo Abdusamatov, head of the space research sector of the Russian Academy of Sciences’ astronomical observatory, in his press release in 2006.
http://en.ria.ru/russia/20060825/53143686.html
This is a very rough calculation, so please don’t take it as a firm prediction – I am most definitely not a polar ice or ocean expert. There are many other factors, such as the brutal winds and currents which blast through the Drake Passage, which would likely impede the formation of sea ice. On the other hand, the growth of ice would increase the albedo of an enormous area of ocean, causing more sunlight to be reflected back into space – though as we are talking about polar ocean, it doesn’t receive much sunlight to start with.
Story Title:
One line summary of story: The growth of Antarctic ice
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Sounds about right. More than close enough for government work.
Unfortunately, from my experience, our government does not work.
The government has been accomplishing its agenda with great efficiency.
— It’s just what *you* want.
At least not on this topic! AMEN
Sure the government works. They’ve been busting their collective, Marxist/socialist backsides trying to saddle and ride this global warming hoax. ‘Er horse. And their backsides were already cracked.
It’s sounds very chilling to me.
The closest part of Antarctica to South America may also be the warmest.
A number of active underwater volcanoes have been reported in this region and this may extend this estimate.
Let’s not go down the Warmist’s route. The problem with estimates / predictions like this is that they will most likely fail due to an ever changing climate. Dr. Peter Wadhams has said that the Arctic ocean will be ‘ice-free’ no later than 2016.
Jimbo
“Lets not go down the Warmist’s route”
I heartily concur!
.As the global temperatures have plateaued for a decade and a half and as this fact sinks in, the Skeptic, and I’m as skeptical as one gets, are increasingly showing signs of taking up the warmist theme of making what could easily be seen in the future as another science destroying bout of unsubstantiated predictions for a future cooling world where predictions, to gain increasing recognition for their proposers are constantly increased in volume and extent as to the new set of climatic dangers suposedly facing mankind all over again.
We’ve had enough of truly stupid and totally irrational planet dooming predictions from the rabid far left watermelon eco-loons including numerous so called scientists, or at least they have some letters after their names which they assume gives them the right to call themselves scientists, who have demonstrated their personal and mindless inability through the extremism of their predictions to think and behave in a rational, considered and thoughtful manner as befits a genuine scientist.
So as skeptics lets not also be sucked in to that prediction game as to do so will mean that those of us on the skeptic side who have tried to keep our beliefs and understandings firmly fixed in the realities of the great swings in climate that Nature regularly imposes on the planet are not eventually seen to be no better than the mindless, rabid and ultimately failed warmists and their catastrophic climate cult fixation.
To paraphrase Jimbo again;
Let us a skeptics not now also go down through the warmist prediction morass for there is nothing at the end except disappointment, despair, fear, dismay, distress, disparagement and complete denigration and ultimately a total loss of trust in the integrity and honesty and clear sighted-ness of those Skeptics who so openly and so forcefully and through the passing of many years, stood tall for truth and honesty in science and politics through all of the worst that could be thrown at them by the warmists over the past two decades
I had previously predicted 2050, so 2055 seems entirely reasonable. Got me banned at Grist. LOL
Haven’t the GCM’s already model the Antarctic ice bridge to South America ?
/sarc
That only takes into account growth from one side certianly if ice formation is occuring from the Antartic side and it is cold enough to reach South America there will be ice formation form the South American side like happens in the shallower water every year in the Arctic.
The Antarctic sea ice growth is actually very even all the way around the continent.
Actually … no. Look at the picture. The area in white (ice plus land) is roughly circular. However the land portion is not circular. That means that the sea ice growth is not very even at all.
False.
The fixed shelf ice is NOT included in NSIDC’s sea ice calculations and records. The result is a nice, even circle around the total area of Antarctica + shelf ice.
“… even all the way around the continent.”
Continent is land, not shelf ice. The growth of the sea ice is very limited around the Trinity penisula compared to the rest of the continent.
I think it’s too stormy there – winds and waves will break up new ice in that region and keep it well flushed.
True. Maybe a better question is when will ships stop going through there?
Then the Panama Canal raises its rates 10 fold..
At the moment the canal saves a distance of 8,000 miles….
The bill for a standard fee for a container ship that fits the locks is about $350,000.00 !
The Chinese are working on a new canal through Central America. They must know something. Maybe they are planning on building bigger ships or they don’t want their access to the Atlantic cut off for political reasons or their expecting a lot of icebergs down there in the future.
Panama is working on a new Canal. Basically their economy depends upon the revenue from it, and as ships have gotten larger, the existing canal is getting less usage. China is probably a bit late to the party.
Maybe, maybe not. We cannot tell.
The currents will likely keep part of the area clear of surface ice, but at the expense (greater area) of sea ice away from the narrow reaches between of Cape Horn and the Peninsula. Regardless, this is an assuming (amusing ?) exercise to tweak catastro-physicists who proclaim catastrophic loss of Arctic sea ice….
It was open during the LIA, probably because of the wild seas, but if it gets colder than the Dalton then all bets are off.
It was open during the Maunder, too, which was the depth of the LIA and colder than the Dalton.
Agreed … hell of a Cape to sail though.
I managed the trip one time back in 1986 one a friends yacht. I vowed to never make the trip again because it was so brutal, but a few months later I was sailing through the very same stretch of ocean, but for the US Navy. Never again!
unless it’s done on a submarine, at ~ 400 feet depth! Even then you can feel hurricane strength wave action. The sub I served on went below a hurricane once and it was still a bit roller-coster’ish.
Eric !
Not gona happen ! [Oh, your post is a funny funny, I agree. But I must add … ]
Why? Currents!
[Think of the movie ‘Master And Commander: The Far Side of the World’ of a few years ago. Yes, a fiction. And Yes, it gives a sense of sailing the oceans in the 19th century and the odds of survival.]
The southern ocean sea ice area extent took, just, a little pause before the “roll-over” to occur.
[you know the link]
🙂
Right. Currents are very strong in that area. Any sea-ice will be whisked away.
LOL, so I would expect to see the following headline in the media soon. “Antarctic Ice expected to collide with South America by 2050….Due to Global Warming”
A lot more scientific than the IPCC’s methodology…
Per IPCC methodology, the estimator must first pull a number out of his posterior, then transpose two digits.
I predict the antarctic ice field will reach Tierra del Fuego by 2006.
Has there been an ice bridge across that gap at any time in the past? How long ago?
Don’t confuse volume with area: “…what is the perfectly circular volume of sea ice required to increase the radius by another 500 miles?”
Nope! you have to use the partial circular area formulas for a beanie cap.
NOT a flat circle.
You said it: “… partial circular area formulas …” – not “volume formula.”
Show me a “circular volume” formula. Spherical volume formulas – Yes; Spherical surface area formulas – Yes; Circular volume formulas – No! Well, maybe if you employ fractal transformations you can get dimensions higher than 2, but that’s not being done here.
Volume? So, what thickness (depth) of sea ice are you going to assume?
The partial area of a surface of a sphere depends on the sphere’s radius and latitude (in this case) of the cap being analyzed.
Compared to the radius of the Earth and the small “beanie cap” extension of ice to the tip of S. America, the depth of the ice is negligible. In the spirit of the problem as presented, (“…if you squint hard Antarctica is a circle”), a simple projection from spherical 3d to Euclidean 2d is good enough for approximating a length of time.
“Circular volume” seems like a neologism, but if you were forced to define it would you not perhaps equate it with “cylinder”?
Depending on the axis of movement (translation or rotation) for the circle, you could sweep out a cylinder, sphere, or torus. If scaling is employed while translating, then you can get a frustum, cone, ellipsoid, and any number of weird, unnamed objects.
When M Mann abandons his climate models….in other words about the same time hell freezes over.
http://en.wikipedia.org/wiki/History_of_Antarctica
snow-covered mountains” beyond the 64° S in 1603
in 1615, they proved that the Tierra del Fuego archipelago was … not connected to the southern land
the pack ice in 52° S in January 1700
ice-cumbered sea nearly in 55° S in 1730
none of them before 1770 reached the Antarctic Circle
On 17 January 1773 the Antarctic Circle was crossed for the first time
reached 67° 15′ S by 39° 35′ E, where their course was stopped by ice.
was stopped by ice in 61° 52′ S by 95° E
compelled after reaching 67° 31′ S to stand north again in 135° W
blocked by ice four days later at 71° 10′ S by 106° 54′ W
On 30 January 1820, Bransfield sighted Trinity Peninsula, the northernmost point of the Antarctic mainland
“71° 10′ S by 106° 54′ W”
For anybody not familiar with Antarctic sea ice extent, map the above using your favorite mapping software.
I was thinking of saying ” 2019, the data is already written moderated and accepted for publication” but I sit on the wrong side of the fence for that.
Actually I think the solar hemispheric bias will drive the PDO negative thus promoting a more active arctic-both in sea-ice growth and hemispheric cooling. In my humble opinion.
Mr Worrall is not using the proper formulas.
…
The area covered by the ice is not a circle, it is the cap of a sphere.
..
The correct formula is
.
A=2& pi;rh
..
As per this diagram.
..
http://en.wikipedia.org/wiki/Spherical_cap#mediaviewer/File:Spherical_Cap.svg
Yeah – We fixed that.
It is worse than you think.
We only need 12 years to reach Cape Horn.
I understand albedo in the form of clouds, which do not allow sunlight to reach the earth’s surface, but I’m lost on ground level albedo. Wouldn’t the sunlight reflected off the ice be trapped by the greenhouse gases just the same as radiated heat? Thanks for the help.
During winter in polar regions there is not much sunlight to reflect. At the south pole the sun has been away since March 21st and is just now back again since September 21st.
False. Even at its minimum sea ice extents, the constantly increasing “excess” Antarctic sea ice is reflecting more and more solar energy. At its minimum sea ice extents, the edge of the Antarctic sea averages right at 67.2 south latitude. At that latitude, the Antarctic sea ice receives and reflects sunlight every day of the year.
Even today, at the equinox, the south pole is getting enough solar energy to reflect energy into space!
Not so in the Arctic. The vast majority of Arctic sea ice lays well north of 71 north latitude, and it IS hidden by darkness more than half of the year.
But it is even worse than you think!
When the Arctic sea ice is exposed to 24 hours of sunlight, it is receiving the LEAST solar energy of the entire year – less than 1315 watts/m^2 at top of atmosphere!
When the Antarctic sea ice is exposed to 24 hours per day of sunlight, it is receiving 1410 watts/m^2 at the top of atmosphere.
RA
When you run through these numbers it makes me want to go out and buy a large globe. A lot easier than the flat maps in visualising what is going on and comparing latitudes in NH to the edges of Antarctic sea ice.
Incoming sunlight is mostly shortwave. It doesn’t get absorbed by GHG’s regardless of which direction it happens to be going. When the shortwave is absorbed by earth surface on the other hand (as in absorbed, not reflected) the surface radiates that energy back out. But since the earth is no where near as hot as the sun, the energy is radiated out at a much longer wave length, and that’s the wavelength GHG’s absorb at.
Here is a graph that should help explain:
http://commons.wikimedia.org/wiki/File:Atmospheric_Transmission.png
Thank you for that reply davidmhoffer. I was ignorant of the main difference, which you explained clearly. That graph sure makes me wonder what all the CAGWers are in such a tizzie over. LOL.
But Judith Curry measured the much dirtier, multi-year Arctic sea ice albedo as low as 0.38 in late July, with an average low of 0.43 for most oh July and early August. So, not as much energy is reflected from the Arctic as was previously thought.
The Antarctic sea ice is 90% fresh ice, covered with new snow. Its year-round albedo is 0,83 to 0.86 Much, much higher.
so, you have the obligatory rolling stones reporter there stating half truths and treated as though nothing is wrong with what he says. the scientist is dragged down to this chaps level by using him as a prop, and you must question his motives. typical climate science piece.
the reality is regardless of rapid global co2 increases sea level rise is not accelerating, the arctic and antarctic are tied to natural cycles and while the arctic may be losing a fair bit of sea ice extent antarctica is gaining. sea ice volume losses are guess work, grace and other forms of modelled volume estimates are not available for any reasonable length of time. IPCC models of BOTH arctic and antarctic sea ice extent predict a NEGATIVE trend-
http://www.climatechange2013.org/images/report/WG1AR5_Chapter09_FINAL.pdf
page 789
so it is obvious that our ‘understanding’ of ice loss and sea ice extent is poor. with so many excuses for the cessation of global warming (the one predicted by climate scientists, not the alarmist make it up as you go version), you know the one where co2 in the atmosphere warms the surface and should result in more water vapour as a positive feedback, an upper tropospheric hot spot, INCREASING SURFACE TEMPS etc.. it is just too bloody hard to believe a word any of these snake oil salesmen.
No, The reflected energy is in the shortwave bands that the atmosphere is transparent to. The Greenhouse problem only comes into effect when it is thermalized by absorption then re-emitted in the long wavelength IR bands.
Eric!!!!
You can do better than this!
Now, let’s get serious here.
Radius of the earth = 6371 km.
Area of Antarctic land mass = 14.0 Mkm^2
Area of shelf ice = 3.5 Mkm^2 (NSIDC doesn’t include this in the sea ice extents nor area.)
Sea ice extents at minimum = 2- 2.5 Mkm^2
Minimum total area of ice at sea ice minimum = 14.0 + 3.5 + 2.5 = 20.0 Mkm^2
Today, at maximum sea ice extents = 20.5 Mkm^2,
Area_Maximum = 14.0 + 3.5 + 20.5 = 38.5 Mkm^2
(The usual Antarctic sea ice maximum is actually in 8 – 15 days from now!)
So, the actual latitude for a spherical earth for any Area_Total =
=DEGREES(ASIN(1-(Area_Total)*10^6/(2*PI()*6371^2)))
(using excel “arithmetic” notation)
So, at 2.5 Mkm^2 at minimum, the average latitude of the Antarctic sea ice extents = 67.2 latitude
(right at the southern polar circle.)
And, at the maximum antarctic sea ice record extents of 20.5 Mkm^2, total area = 38.5 Mkm^2, so
the average latitude = 58.1 degrees
Cape Horn = right at 56 degrees south latitude.
But, the ships go around it a little bit south (by about 20 kilometers to clear the rocks and allow for storm winds), so we can accurately use 56.0 degrees – and easily assume that the very narrow Straits of Magellan are frozen over also.
Reversing the above equation, latitude 56.2 requires 43.0 Mkmm^2 of total ice. (if you have a symmetric beanie cap over the south pole.)
43.0 – 14.0 -3.5 = 26.5 Mkm^2 of sea ice extents is needed when the Antarctic sea ice hits Cape Horn.
Net, we need only 6.0 million more kilometers of Antarctic sea ice.
But! Look at the increase in the Antarctic sea ice anomaly in the past 4 years.
2011 = -0.5 Mkm^2
2012 = +0.0 Mkm^2
2013 = +0.5 Mkm^2
2014 = +1.1 (In January)
2014 = +1.6 (in September)
At the recent rate of increase of 500,000 km^ per year, it will take less than 12 years to gain another 6.0 Mkm^2 …. And it is even faster if you include the recent acceleration …
Yes, I should have calculated the area of Antarctica as a surface on a sphere instead of a flat circle – even scarier 🙂
> Area of shelf ice = 3.5 Mkm^2 (NSIDC doesn’t include this in the sea ice extents nor area.)
The area of the ice shelves is about 1.6 million sq km.
Good find. I agree.
I also can’t find a reference claiming that the ice shelves are not included in the 14 million sq. km. Do you have one?
Email reply from the NSIDC.
It seems to me that the ice is very close to South Georgia Island which is on the same latitude as the southern tip of South America. So you don’t rally need a perfect circle and I reckon 2025.
Good thing all that ice is on the bottom, if it was on top I’d be afraid it might flip the world over. Good to have coutnerweight like that keeping us northerners up top where we belong… phew.
But ice is lighter than the colder water that is sinking and flowing north so this means it WILL reach a tipping point faster! 8<)
Don’t tell Hank Johnson, we wouldn’t want him to get all wound up again.
I know this is a fanciful calculation, but your units – and results are (almost) all wrong.
> Antarctica, according to Wikipedia, is 14 million square miles.
No, 14 million square kilometers.
> Sea ice this year covered 20 million square miles.
20 million square kilometers. And this is ice extent, not area, so “covered” is not accurate. (Antarctic sea ice area is about 16.6 million square kilometers.)
> So the radius of our “circular” Antarctica is approximately 3289 miles
Again, kilometers. And, not really – you’re not accounting for the curvature of the Earth.
> According to Wikipedia, the distance between Antarctica and South America is 500 miles.
This is the distance to the Livingston Island, not Antarctica – but what you’re really after is the area of a circle centered on the south pole and just touching South America. Let’s use Cape Horn, although it’s not part of the mainland. It’s at 56 deg south. The area of a spherical (we’ll assume the earth is a sphere) cap is 2 * pi * r * h = 2 * pi * 6378 km * (1 – sin(56 deg)) * 6378 = about 41 million square km, so we need another 21 million square km, or about twice as much as we have now.
> At say 300,000 square miles growth per year (lets not forget, this year busted records by 600,000 square miles)
Nope. This year’s record was 600,000 sq. km. higher. Assuming half that, 300,000 sq. km. per year, the Drake Passage will be (at least 15%) blocked in 70 years, not 36.
Nope. Your numbers are incorrect. See above.
What formula are you using for latitude vs area?
I forgot to add in the area of Antarctica (14 million sq km) – so we need 6 million, not 20 million sq km.
However, my point about area vs. extent stands. The 20 million sq km “extent” is at least 15% covered. The actual area is 16.6 million sq km.
Think of the catastrophic impact on resort beaches as ocean levels drop. Ferry docks throughout the world will be left high and dry. Whales will be beached, Venice will lose it flush waters.
Sea ice does not affect sea levels.
You don’t recognize sarcasm very well, do you? 8<)
How long to get to Cape Agulhas? Maybe 2-2.5 times as long (eyeball estimate)?
Albedo is more important at the South Pole than at the North as during the summer when that sun is shining on and melting the ice, the Earth is closer to the sun, the increase in albedo with all this extra ice must be huge.
True:
When the Antarctic is exposed to 24 hours of solar energy per day, it is hit by 1407 watts/m^2 at top-of-atmosphere.
When the arctic is exposed to 24 hours of sunlight, that sunlight is only 1315 watts/m^2. Almost 100 watts/meter less.
We calculated that difference for today’s values – not even the mid-summer values you are assuming.
Today, 22-23 September, the 1.6 Million sq kilometers of “excess” Antarctic sea ice is reflecting five times the energy that the Arctic sea ice is receiving.
At 80 north latitude on September 22 at noon on a clear day, a flat surface only receives 106 watts/m^2
If sea ice, 22 watts is absorbed, 84 are reflected back into space
If open ocean, 72 watts are absorbed, and 33 are reflected and lost into space.
At 58 degrees south latitude the excess Arctic sea ice is hit by 515 watts/m^2
If open ocean (which was last year), 478 watts are absorbed, 37 watts are reflected.
if sea ice (this year!), 91 watts are absorbed, and 424 watts are reflected back into space.
> At 80 north latitude on September 22 at noon on a clear day, a flat surface only receives 106 watts/m^2
Where do you get this number? Cos(80 degrees) = about .17. That would be well over 200 watts/m^s (at noon). Are you thinking of the average insolation over 24 hours?
> At 58 degrees south latitude the excess Arctic sea ice is hit by 515 watts/m^2
That would be Antarctic sea ice, I’m pretty sure the sea ice covers very little water this far north (see extent vs. area, and look at the map), and, again, is this an average or a peak value?
No Pablo: You’re using the wrong approximation for air mass. Near the poles, you can’t just use the simple cosine that (almost) works close to the equator.
What attenuation factor are you assuming for your air mass? Polar or near-tropical?
Haven’t we learned from the warmists about the perils of assuming current run rates continue indefinitely? We do not live in a linear world. More than likely the circumpolar current will keep the straight ice free until something more permanent, like a continent, blocks it’s path.
Yeah. You’re right. But it is more fun to tweak their assumptions and linear scaling.
Yeah. This recent uptick in Antarctic ice is unlikely to be any more significant than in the long term than was the 1998 super el nino. But boy is it fun to bring that graph up on your laptop, spin it around in a meeting, and ask people how that’s even possible….
No one has mentioned this yet, but the increasing volcanic activity and thus the dust and other aerosols that are lifted into the atmosphere will help increase the growth of ice.
[Why would more dirt increase the growth of ice? .mod]
Please refresh my memory about “increasing volcanic activity.” I don’t recall that claim.
I have the same problem skywolfe, I don’t remember global volcanism being any higher.
But as for the mod’s question, if sunlight is dimmed globally by high altitude particles there could be an increase in ice growth, of course it probably balances out later when those particles fall on the ice after a few years and cause hot spots to melt into the ice.