Sometimes it’s just the way you look at things that gives a better understanding. Simply shifting Point Of View is sometimes enough. At other times, a full motion animation can make things clear over time.
Nullschool is a computer simulation (but claims to be based on actual collected data). I’ve not taken the time to sort out which bit is simulation (model) and which bits are data based. I’m mostly presuming they start from actual data now and in the past, then run it forward. FWIW, comparison of snapshots with other data maps (Sea Surface Temp, Wind, clouds, storms) seems to show a decent match).
So I was looking at another article on Antarctic Melting…
that once again pointed out that it is only the West Antarctic Peninsula that is warming up a bit (if you can call frozen ‘warming’…) and not all of Antarctica. They mention the usual reasons that are put forward as “possibles”. Perhaps it is volcanoes under the ice. Perhaps it is the latitude. Perhaps.
I’m going to offer another “possible”. Perhaps it is the wind, and where it comes from. Looking at Nullschool, it looks to me like the WAP is being warmed by a nice Pacific breeze. Warm air entering on that side, frozen air exiting the other side of Antarctica. First off, the link to Nullschool:
At the moment, I’ve clicked on a spot on it, just ‘up wind’ of the WAP, that is showing 4.9 C with winds headed straight at the WAP. Somehow I think that matters. Here’s a screen capture I just did (that’s a bit funky to do on the Chromebox):
There’s a little marker circle where I clicked in the approach winds. The text in the lower left shows the lat long and temp. 4.9 C. A little harder to see is a similar warm wind headed south from near South Africa. That air gets entrained into the slighter further south wind going the other direction toward the WAP. Looking at the wind flow lines, you can see that the warm source air flows over the WAP, and that the very cold frigid air from the central continent vortex tends to exit from the continent on the far side. It does vary some with which side has the daylight, but generally the flow is off the continent on the parts away from the WAP. (In what I’ve observed so far).
This is surface winds from 20 October 2014 at 10:50 AM Eastern USA time.
While it does not show the temperature gradients of the prior picture, the wind patters stand out a bit more. Notice that the generally circumpolar wind tends to ‘swing out’ over Chile / Argentina and then back toward the WAP? The South Polar vortex stands out better too, and you can see the flow lines away from it covering more of the area toward the bottom of the image.
Here I’ve marked a spot out near the edge of the ice shelf. It is all of -12.5 C and is about the same latitude as the WAP. Well, really further from the pole than the WAP… but the point is that it is much colder here than in that relatively warm wind off of the ocean near Patagonia. So how cold is it in the center of the continent?
Yeah, that -50.8 C is cold… While they show up better in the animated version, you can still see the flow lines of very cold air both ‘up’ and ‘down’ in this image.
I have other images, with other temperature captures and at other heights. They generally show warm air flowing inward and cooling until they hit the vortex, then head down. Eventually, at the surface, the cold is forced back out again, freezing things along the way. Except that outflow is not able to overcome the wind inbound from the Pacific over the WAP. (This might change at other seasons. I intend to ‘check in’ on this over the next year to see if any seasonal patterns / changes happen. For now, it is only ‘what it does right now’.)
The key take away for me is that -50 C and -12 C are simply NOT “melting”. Most of Antarctica is astoundingly cold, having just recorded ‘record ever’ frozen cold and ice extent. The only place less than Oh My God Cold, is the WAP, and that is getting a wind off the Pacific (that despite starting out at about 8 C at the peak of the ‘loop’, drops rapidly to 4 C on the approach, and is down to -0.6 C as it approaches the tip of the WAP. At the root of the WAP, it is down to -15 C, and the further inland you go, the colder it gets. That’s a range of 25 C from origin of the air to the end of the WAP. That is one heck of a lot of heat being dumped.
IMHO, their is NO warming in Antarctica. There is a lot of cooling. There is a very small part of the WAP that is not as cold as the rest of Antarctica, but that is just due to a large flow of warmer ocean air being cooled to freezing as it passes. Again, not warming, cooling that air.
In the discussion below reference is made to the Mean Sea Level Pressure graphs. I’ve added three of them here. South Pole 1000 mb (as discussed) and a matched set of 700 mb for both N and S poles as I think they show the wind structure a bit better.
First, the 1000 mb South Pole:
Then the 700 mb South Pole followed by the 700 mb North Pole:
Overall, the North Pole is a bit less extreme in the pressure differential, but it is still there even though much of it shows as a lighter shade of yellow with purple spots in it, instead of a clear band of purple with brownish spots. Maybe displaced a bit toward the N. America side (and less circular) due to the land mass vs water distribution. Same effect though.