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Rob Dekker

NIce summary, Neven.
It still amazes me that despite the cyclones, and despite the flying start, we still can't quite rank where 2016 will end up in September.
It may come down to the question of if the "arm" of low concentration ice towards the ESS will melt out or not.

wayne

Yes and so goes another extent number shake up , once more, the prominent cyclone on the 20th had significantly different wind directions over the icescape than the current one. In fact opposite in most parts. In a matter of days! Extraordinary. There has been a new more vigorous summer circulation afoot since the great melt of 2007 and especially of 2012. This melt season is really showing it.

Artful Dodger

Hi folks,

Yes indeed shoppers, come see the new models of 'Kelvinators' for 2016.

Still available in classic "Arctic White", but now also in the new exciting hybrid model "cold-core at surface/mid levels, with warm-core characteristics at the 200 mb level".

Get'em while they last. Arctic sea ice is going fast.

w całości - NW Passage

Cheers,
Lodger

Jim Hunt

The 2016 (Great?) Arctic Cyclone is down to 970 hPa once again this morning (UTC), and there's also a 1030 hPa high over Greenland:

http://GreatWhiteCon.info/2016/08/the-great-arctic-cyclone-of-2016/#Aug-23

Meanwhile the University of Hamburg are busy processing their high resolution AMSR2 data back to summer 2012. Here's 400 pixels worth:

That’s sea ice area for the Arctic Basin, comprising the CAB plus Beaufort, Chukchi, East Siberian and Laptev Seas.

Where do you suppose the red line is heading next?

navegante

Rob, the dispersing effect of a very strong cyclone, for 8 days now, lingering within the central pack. Yet extent dropping steadily.
If peripheral waters keep melting at this rate for some weeks expect sustained drops...

EthonRaptor

Wouldn't get too excited about naming the storm. After all Sandy was not a hurricane at landfall.

dominik lenné

How does PIOMAS deal with such a dispersed and at the same time compacted ice mass?

wayne

Jim ,

"Where do you suppose the red line is heading next?"

Down Jim, down. but erratically like the continuous changing winds. Speaking of unsteady, Goodbye Waves in Fram Strait had no continuous geometry during the last three days, while the melting sea ice remained relatively in place:

http://eh2r.blogspot.ca/2016/08/goodbye-waves-lack-of-geometric.html

also 2013 had a great melt near the Pole but not measured properly
thanks to the magical mystical 15% minimum sea ice per grid rule:

http://eh2r.blogspot.ca/2016/08/north-pole-sea-ice-what-we-can-see-2016.html

Rob Dekker

dominik said

How does PIOMAS deal with such a dispersed and at the same time compacted ice mass?

That is a very good question.
Anyone with more knowledge about this please correct me, but from what I understand, PIOMAS adjusts their "ice thickness" at any particular grid point by assimilating the ice concentration observation with the modeled ice thickness. So if one gridpoint has modeled ice thickness of 1 meter, but the ice concentration observation is 50%, then they present the ice as having 0.5 meter thick ice.

That way, ice volume calculations are following ice concentration quite nicely and do not show unrealistically thick ice in the marginal ice zone.

Tony

MASIE is showing NH (presumably, Arctic) sea ice extent below that of 2012, at the same point. The main NSIDC daily plot isn't showing that. What should I make of this, as MASIE has a higher resolution?

Cato Uticensis

Based on synoptic charts, the next 7 days will be very challenging for arctic ice, due to the persistence of a huge LP system along the siberian coast of the arctic, coupled with a smaller but the same persistent HP on Beaufort and CAA.

Very strong winds leading to compaction, warmer air pumped in from Pacific ocean and even increased transportation through the Fram. This configuration in my view is much more impacting than the arctic cyclone.

I wouldn't be surprised if we got >100,000 kmq drops in the next few days and as of today I can't see 2016 do any better than 2007. Second place after 2012 should be a rather easy catch IMHO.

John Christensen

Agreed that the forecast looks ominous Cato: On the DMI forecasting model you see how a larger area of thick ice is entering Fram:

http://ocean.dmi.dk/anim/index.uk.php

Cato Uticensis

Yes John, and based on the latest GFS update transportation could be relevant for the next 7 to 10 days... Let's wait and see whether the next runs confirm the current view. There's much alignment between ECMWF and GFS,with other models like GEM slightly less ominous, as you say... But the forecast looks solid overall.

Tony

Well, 2012 has gone below 2016 again, on Masie. They seem to be vying for the lead.

Robert S

I think if the forecast 957 hPa low on the 29th actually happens we can start talking about "great".

wayne

Cato

"I wouldn't be surprised if we got >100,000 kmq drops in the next few days and as of today I can't see 2016 do any better than 2007. "

Yes on the >100,000 drops, but the over all look at present is very bad:

http://eh2r.blogspot.ca/2016/08/huge-sea-ice-area-is-on-razors-edge.html

Hans Gunnstaddar

Wayne, that is quite an amazing change from the 23rd to the 24th over a huge area!

John Christensen

Final blow?

From ecmwf it seems like the cyclone will provide a final blow this weekend and then become disorganized with overall higher SLP across the CAB developing next week.

John Christensen

Ominous:

The DMI forecast of sea ice drift seems to confirm the ecmwf forecast, which has worsened since yesterday:

http://ocean.dmi.dk/anim/index.uk.php

With the cyclone displacing itself towards Barents/Kara, winds will be strong from the north through Fram and ice drift in a southerly direction is certainly picking up.

Perfect mix for late season ice volume drop..

Lawrence Martin

John Christensen

All models including ECMWF are indicative of the storm lasting well into next month...

http://www.tropicaltidbits.com/analysis/models/ecmwf/2016082412/ecmwf_z500_mslp_nhem_9.png

NeilT

DMI 80N temperatures have now dropped below salt water freezing levels and the Bremen AMSR2 concentration is starting to show the NP and immediate area starting to close up after being ripped apart by the storms.

Any huge drop will come from the periphery and, as we've seen, some of that is more resilient than was expected.

I don't expect any major surprises unless it turns up as a huge polynya on the Atlantic side of the pole amongst the ice there. All that heat has to go somewhere after all.

John Christensen

"All models including ECMWF are indicative of the storm lasting well into next month..."

I do not see that: ECMWF medium-range has the cyclone significantly weakened by Wednesday next week and by Saturday the minimum SLP is above 1000mb:

http://www.ecmwf.int/en/forecasts/charts/medium/ensemble-mean-and-spread-four-standard-parameters?time=2016082500,0,2016082500&parameter=MSLP&area=NorthernHemisphere

I wouldn't be concerned about a forecast going beyond nine days, but a week from now we will know if there is potential for another cyclone to develop.


wayne

Hi Hans

Indeed, that is quite possible, if sea ice has thinned and melted enough, it would simply vanish, but before that variable wind movements would make it look strange. Unlike 2013 which had some significant melting which did not show up at all on JAXA due to 15% sea ice per grid rule:

http://eh2r.blogspot.ca/2016/08/north-pole-sea-ice-what-we-can-see-2016.html

2016 has a lot of grids just about to become 14% sea ice, while 2013 had lots of grids which were maintained just above 15 throughout.

wayne

There is good reason to hope that the forecasts for more Cyclones would be incorrect. The Trans Polar Stream is just about to be a real river carrying fluidly sea ice directly to the Atlantic, once a small ice dam of denser ice, North of Spitsbergen collapses, that will be so:

http://eh2r.blogspot.ca/2016/08/the-trans-polar-stream-is-becoming-like.html

Tony

MASIE has 2016 again squeezing below 2012.

https://nsidc.org/data/masie/masie_plots.html

Can anyone comment on the difference between the MASIE plots (which are available via NSIDC) and the main NSIDC plot? It's quite marked.

http://nsidc.org/data/seaice_index/images/daily_images/N_stddev_timeseries.png

wayne

It may be too late, the reduced pressure by lack of solid sea ice going to Fram Strait by the Trans Polar Stream will likely accelerate the flow outwards to Fram even before winds would flush out sea ice more by the cyclone about to strike in the same area:

http://eh2r.blogspot.ca/2016/08/trans-polar-stream-first-time-so-wet-in.html

Jim Hunt

Tony - I discussed MASIE versus the NSIDC's Sea Ice Index with NASA's Walt Meier not so long ago:

http://GreatWhiteCon.info/2016/02/dmi-masie-and-the-sea-ice-index-an-interview-with-walt-meier/#Walt

In brief:

MASIE repackages data from the NIC, and incorporates an ice edge hand drawn by analysts working with whatever satellite data they have available at the time. It is an “operational” product designed to produce a “best effort” ice edge each day, based on whatever data may be available at the time.

On the other hand the SII was designed to use a consistent methodology over a long period of time using a single type of sensor. 100% automatically processed passive microwave data is the “gold standard” when it comes to determining sea ice trends.

Bill Fothergill

@ Tony,

In his GWC article mentioned above, Jim's closing remarks sum it up pretty well...

"So there you have it. If you’re on the bridge of a vessel sailing in Arctic waters then MASIE is the right tool for the job. If on the other hand you’re sat in front of a computer trying to get the best estimate of trends in Arctic sea ice extent then the Sea Ice Index is what you’ll grab from your toolkit."

Neven

Tony, thanks for an interesting question, and sorry I didn't answer earlier. I went into this a bit in the latest ASI update under the compactness header.

I think I'll shoot off a mail to Walt Meier tomorrow.

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