Just a few days ago I was crying with joy that PIPS had finally come back online again. The ice displacement maps are indispensable to my amateur analysis of what's going on in the Arctic as we speak and so it was great to see it come back on-line. But it gets even better.
Peter Ellis informed us in the comments of the previous PIPS blog post that there was an announcement on the PIPS website:
Since late April/early May 2011, PIPS 2.0 has developed an unrealistic opening in the North Pole region. On 22 May 2011, PIPS 2.0 stopped running because of a numerical instability. Since that time, we have been carefully trying to diagnose this problem (checking for anomalous atmospheric forcing, initial fields, boundary conditions, assimilated satellite ice fields, etc). During this process, the system's ocean model time step was reduced and the system is currently running again. The unobserved opening near the North Pole is still present and can be seen in the ice concentration and ice thickness fields. PLEASE USE THESE FIELDS WITH CAUTION! We have subsequently filled in the period from October 2010 to present with the hindcast using the reduced ocean model time step. Because PIPS 2.0 is a legacy system and will soon be replaced with a new ice nowcast/forecast system (see below), little additional effort will be expended to keep it running.
I think it's fantastic that the people from the Naval Research Laboratory put up this explanation of what has happened. And the announcement that the Polar Ice Prediction System (PIPS 2.0) is now a legacy system, is quite stunning. But not nearly as stunning as the news that it is going to be replaced with a new forecast system:
On a positive note, NRL is announcing the release of the Arctic Cap Nowcast/Forecast System (ACNFS) website. This is the Navy's state-of-the-art coupled ice/ocean data assimilative ice forecasting system for the Northern Hemisphere. ACNFS is currently undergoing operational testing at the Naval Oceanographic Office and the National Ice Center. This work is scheduled to be completed by the end of December 2011.
And my oh my, does this site look promising! Clicking through it a bit I ended up at this page with movies and snapshots of the 1/12° Arctic HYCOM/CICE. Here's how the 30-day animated GIF for sea ice thickness looks:
But there are other animations as well, of sea surface temperature, height, salinity, sea ice concentration and displacement. All in all very overwhelming. I'm going to need a couple of days to let this sink in.
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 :-) )
Posted by: Greg Wellman | July 08, 2011 at 22:46
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?
Posted by: toby | July 08, 2011 at 23:51
Sorry, in my last post I said PIPS when I meant the new model pictured above.
Posted by: toby | July 08, 2011 at 23:53
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?)
Posted by: Greg Wellman | July 08, 2011 at 23:58
Greg,
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?
Posted by: toby | July 09, 2011 at 00:29
Data for the CT concentration map was captured during the day of July 5. Look at the CT map again in 3 days...
Posted by: Artful Dodger | July 09, 2011 at 02:03
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?
http://en.wikipedia.org/wiki/Climate_of_the_Arctic
Posted by: Kevin O'Neill | July 09, 2011 at 02:11
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.
Posted by: Greg Wellman | July 09, 2011 at 02:55
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:
http://www.hycom.org/about
and the CICE (Community Ice CodE) model of Los Alamos National Laboratory:
http://climate.lanl.gov/Models/CICE/
Here's a presentation on the new system, dated Feb 2011:
http://oceanmodeling.rsmas.miami.edu/pdf/003_LOM_2011_oms_pres.ppt.pdf
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.
Posted by: Anu | July 09, 2011 at 05:25
Has anyone else noticed that the PIPS Thin Spot is collocated with the NOAA Hot Spot (a +5C area centered at 165W 85N)?
Posted by: Artful Dodger | July 12, 2011 at 00:12
Indeed, Lodger! Well hot-spotted. :-)
Do you think one has to with the other? The PIPS people would have noticed this, I would think.
Posted by: Neven | July 12, 2011 at 05:59
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?
http://www.youtube.com/watch?v=K-9fXz3Oog0
Cheers!
Posted by: Artful Dodger | July 12, 2011 at 07:52
What, the Enterprise destroyed? Oh my, we are royally screwed then.
Posted by: Neven | July 12, 2011 at 07:56
Trick question. It was the Albedo Flip.
Posted by: Artful Dodger | July 12, 2011 at 08:21