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Greg Wellman

Has anyone compared the total volume implied by the ACNFS map to the PIOMAS volume for any given day? (too lazy to do it myself :-) )


What I don't figure is that just north of the Canadian Archipelago, if you look at the Cryosphere maps or MODIS images, you will see melting, even open water, where the ice is at its thickest according to PIPS.

Does this mean the PIPS model is out of date? Or is something else happening?


Sorry, in my last post I said PIPS when I meant the new model pictured above.

Greg Wellman

That open water is basically a lead that has opened up as the Beaufort Gyre pulls the ice away from the archipelago. If you squint at the ACNFS (aka "new PIPS") animation above you'll see it briefly. The resolution on that map is simply lower than the MODIS image - by quite a lot. (A 1/12 degree is almost six miles, nearly 10 km, right?)



Unless my old eyes are deceiving me, another lead is opening up North of Ellesmere Island. It is big enough to be visible on MODIS images, though not on Cryosphere Today. Any thoughts?

Artful Dodger

Data for the CT concentration map was captured during the day of July 5. Look at the CT map again in 3 days...

Kevin O'Neill

I just happened across Wikipedia's entry for "Climate of the Arctic" - I was just looking for a map with place names, but the caption is what really caught my eye:

A map of the Arctic, the red line indicates the 10°C isotherm in July, commonly used to define the Arctic region border, and the white area shows the average minimum extent of sea ice in summer as of 1975. CIA World Factbook

The white area mentioned is almost identical to today's SIE. In other words, the average SIE minimum circa 1975 is now being reached in early July. Does the CIA have a known liberal bias too?


Greg Wellman

Toby, yup, I see that lead too - what can I say, the pack is a lot more mobile than it used to be. Whether the thickness on either side of that lead is what ACNFS says it is ... that's sort of the motivation behind my first comment on this post. The actual presence of the lead doesn't utterly preclude that.


Wow - the new Arctic Cap Nowcast/Forecast System looks like a quantum leap over PIPS 2.0.
I guess this is what PIPS 3.0 became.

PIPS 2.0 was based on the Hibler and Bryan coupled ice-ocean model from 1987. The new one is based on HYCOM (HYbrid Coordinate Ocean Model), the work of a large consortium of institutions doing data assimilative modelling of the ocean:

and the CICE (Community Ice CodE) model of Los Alamos National Laboratory:

Here's a presentation on the new system, dated Feb 2011:

The work of university professors, and assimilating all kinds of data? That sounds too much like PIOMAS - the skeptics aren't going to like it. Especially if it gets the ice thickness correct.

And that ice thickness chart looks very professional, Neven - I hope Cryosat-2 starts releasing data presented that nicely.

Artful Dodger

Has anyone else noticed that the PIPS Thin Spot is collocated with the NOAA Hot Spot (a +5C area centered at 165W 85N)?


Indeed, Lodger! Well hot-spotted. :-)

Do you think one has to with the other? The PIPS people would have noticed this, I would think.

Artful Dodger

Of course correlation is not causation, but i like to keep a eye peeled for anomalies :^$

So remind me, is the Enterprise destroyed by Klingon Disruptors, or because Scotty fails to reassemble the Shields?




What, the Enterprise destroyed? Oh my, we are royally screwed then.

Artful Dodger

Trick question. It was the Albedo Flip.

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