Any ideas about why Antarctica is melting slower than the Arctic

[Robert Zwilling]

Its has the highest average elevation for all the continents, maybe it keeps more ice higher above sea level so it is better insulated?

The northern zone where the average temperature is warming up faster extends past the Arctic zone. In the Arctic it is warming at twice the average rate of the rest of the planet. Since ice absorbs heat as it melts, without the all that melting ice the Arctic could be warming up at an even faster rate.

 

[Venusian Broon]

Antarctica has ice sheets kilometres thick over the inner part of the continent. The Artic on the other hand is mostly floating on sea and (I'll have to checks this, but I'm gyming at the mo') is tens of metres thick - on average. There are similar thick ice sheets in the North, but only in places like Greenland - which are smaller than Antartica.

The problem is, I believe, (I'll dig out the articles if you are interested) is that the bottoms of these ice sheets in Antarctica, when in contact with the sea are melting faster than expected, so vast chunks of 'land ice' may get calved very quickly into the sea - which could have terrible consequences for sea level rises.

 

[Robert Zwilling]

I'll dig out the articles if you are interested

I'm interested. I thought the Arctic had a greater exposure to melting from the bottom up, but that doesn't explain Greenland, where you can book a tour to watch the ice melt.

 

[Brian G Turner]

I would presume the first answer is due to circulation patterns - the second as due to the far larger mass of land and ice at Antarctica requiring far more energy to warm it.

 

[Venusian Broon]

I'm interested. I thought the Arctic had a greater exposure to melting from the bottom up, but that doesn't explain Greenland, where you can book a tour to watch the ice melt.

Yes, I'd guess that because it's mostly sea ice, that there's a limit to how much ice will form, because as you suggest the ocean below is always melting the bottom. (I think!) Whereas the ice on the Antarctic is formed by snow falling on ground and slowly getting squished together into ice - which can form very thick ice sheets* - whereupon it tends to flow to the sea eventually, thinning then calving

I expect you probably see similar scenes like Greenland near the coast of Antarctica where it is a bit warmer. But as you have also pointed out the central part of Antarctica is at a pretty high altitude (the central part is ~3-4000 metres up), so it's a much colder part of the world. Sometimes in the Arctic, in the summer, it can even get above zero deg C, which on average the Antarctic doesn't.
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* Although precipitation is generally so low in the Antarctic that it is officially a desert. The snow builds up these ice sheets over a very long time!

 

[Venusian Broon]

Here's a couple of articles. The second one is the one that I was referring to. Essentially underwater melting is accelerating thinning and speed of ice flows.

Antarctica’s ice is melting three times faster than we thought | WIRED UK

Underwater melting of Antarctic ice far greater than thought, study finds

 

[Danny McG]

Is it not because it's at the bottom of Earth so it's further away from the Sun?

 

[Robert Zwilling]

Is it not because it's at the bottom of Earth so it's further away from the Sun?

There isn't really a top and bottom for the Earth but the Arctic ice and the Antarctic ice properties have a few major differences which seem to make them opposites of each other. The northern hemisphere has more land in it than the southern hemisphere which makes it seem like the top of the world and probably interacts with the wind and ocean currents more than in the southern hemisphere.

The Earth's orbit is elliptical and for some reason, the North Pole is closer to the sun during it's summer season and during the summer season for the south pole it is farther away. There are 3 other seasons and every 6 months the Earth is at a minimum or maximum distance so I don't know what the overall results are. Supposedly for the summer months the difference between the 2 Poles is 6 percent.

The upper atmosphere sucks away heat and the North Pole with no land is low in the water compared to the South Pole which has the highest average elevation of all the continents bringing it closer by a few thousand kilometers to the cooling of the of upper atmosphere.

The Antarctic has a little more ice than the Arctic. Around 10 percent of the Antarctic ice is in the water around the continent. That is around the same amount of ice on Greenland, which is the Arctic land ice. Land ice vs water ice is pretty much opposite for the poles.

 

[Scookey]

It could also be because the antarctic sits on mountainous rock, it isn't being undercut by warming sea water the way the arctic is.

 

[Foxbat]

I wonder if it's anything to do with the planet's tilt?

 

[Danny McG]

Maybe penguin poo is harder to melt?

 

[Scookey]

I wonder if it's anything to do with the planet's tilt?

No idea but pretty sure the volcanic, mountainous nature of what is under the ice helps. Antarctica has the most brutal winds on the planet - over 200mph and sub zero. Now that is what you call wind chill.

 

[Robert Zwilling]

The penguins are plenty tough, maybe they prefer the uncluttered, only partially polluted atmosphere away from the northern hemisphere where 90 percent of humans are camped out.

 

[Scookey]

The penguins are plenty tough, maybe they prefer the uncluttered, only partially polluted atmosphere away from the northern hemisphere where 90 percent of humans are camped out.

The pollution point is very true. In the northern hemisphere even fish stocks can be too polluted to eat on a regular basis. Read a book once about Australia surviving a nuclear war in the northern hemisphere but facing imminent destruction due to the innevitable spread of radiation through the air. Good book, don't remember the title.

 

[Danny McG]

. Read a book once about Australia surviving a nuclear war in the northern hemisphere but facing imminent destruction due to the innevitable spread of radiation through the air. Good book, don't remember the title

Neville Shute - On the Beach

 

[Robert Zwilling]

On The Beach was a favorite choice at the middle school books for sale library shelve, right along with Jules Verne and H. G. Wells.