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pottyprof

Arctic Ice Discussion (the Refreeze 2012-2013)

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As we enter into the autumn and winter periods, ice in the Arctic will grow. After breaking records for the melt season, are there any unusual happenings that will prevent decent growth rates or are we stuck with a low volume, low extent and quality of ice? Is there any research on the current situation that gives us any hope of a recovery? Currently we are at the edge of the yearly switch between melt and freeze and we could see some of both.

Welcome to any new posters to this area. If you have a question about this topic, feel free to ask in the thread and hopefully someone will be able to provide an answer.

The Arctic Ice melt season thread will remain open until the freeze is well under way and to give chance for any summaries.

As always, stick to the rules and enjoy the debate. :)

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PS, your forgot to mention (actually you didn't but), that knives & daggers are to be left at the doorgood.gif

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PS, your forgot to mention (actually you didn't but), that knives & daggers are to be left at the doorgood.gif

Killjoy!

I'd suggest that folk be mindful of the properties of young, salty ice compared to the older ,'fresher' ice when it comes to melt out/ I'd also suggest that the PIOMAS data has proved itself trustworthy so 'average thickness' at winters end is also a good guide to how we have done over the season?

Don't be fooled by ice extending outside the basin. experience tells us that this will play no part in ice min totals (it may also represent the impacts of a new weather regime driven by the extra energy now available in the basin?)

Finally be mindful of the ice flow out of Fram as this is tending to remove a fair proportion of the older ice that survived summer over the winter months.

Recovery? it has taken over 100yrs for us to arrive at this point and ,now we are here, the 'normal oceanic processes' are beggining to change the 'unique' nature of the ocean making it even more unlikely to 'recover'. as we saw this year any 'gains', in older ice ,will be wiped out over a single season leaving us worse off than before. I think our energies would be better spent wondering how the 'new' arctic will impact our world than on wish-casting 'recoveries'?

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Please use the other thread for venturing into speculation, peeps? This is not the place...

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Please use the other thread for venturing into speculation, peeps? This is not the place...

?

If we're speculating on the way the basin acts after this years record losses I'd suggest that this is the place?

Can we expect 'instant' impacts as heat is released back into the atmosphere? how would folk expect to see signs of this over the coming months? Will Barrentsz?Kara have company in the 'low winter ice club' this year?

in the same way that it was 'interesting to speculate about the melt season to come surely it is just as much fun to 'speculate' how ice re-build will be this year after such an extreme melt season.

I'd say 'speculate away' Pete, just link it to the data that you feel important so others can better follow your thinking?

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Come on Ian? You know what I mean...biggrin.png

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Using the NSIDC extent data, with the 79-11 average, the average minimum date is the 12th, with 6,272,000km2. By September 30th, the average extent is 6.826,000km2, so a jump of 554,000km2. I think if we want to reach a respectable maximum by March next year, we need to be beating the average increases from now until then.

The 554,000km2 between minimum and the end of September is the first target. During October, a realistic daily increase to aim for would be 100,000 - 120,000km2/day (the 79-11 average being around 85,000km2).

We're currently about 2.8 million below the 79-11 average, so we have a massive gap to close!

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We're currently about 2.8 million below the 79-11 average, so we have a massive gap to close!

Its not beyond the realms of possibility that we have a really good recovery in extent. Just need to hope then that it doesn't get wiped out to the same extent.

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What would we need for a good quality refreeze?

Would a delayed freeze actually aid in thicker ice formation later due to a deeper layer of mixed cold water forming without being insulated by a thin layer of ice?

The SW winds to the far east of greenland for much of last winter really didnt seem to give us a good pack, however I cant see that a north airflow would help either due to transport through Fram or just transport out of the basin?, Maybe overall light winds here or some southeasterlies which no doubt would be very rare for any prolonged time? I know that a big hight tends to like to settle over greenland presumably due to it having the coldest temps and thus sinking air which generally aids in helping transport through Fram.

Increased precipitation over the basin during a refreeze? Thats gotta be a plus surely?

Volcanic events? Nothing substantial for this year? (if there was it surely would have reduced temps during melt season)

Dipole and jetstream, Higher lat stronger jet, anyone? Is this likely this winter?

Just throwing some ideas around, It would be nice if people could give their views on refreeze factors and magnitude so we can look out for either good or bad signs for this coming refreeze.

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Its not beyond the realms of possibility that we have a really good recovery in extent. Just need to hope then that it doesn't get wiped out to the same extent.

I think with the volume as low as it is, and the thickness as low, it's more than likely that we'll see another massive melt next year, regardless of the maximum. The sea ice just doesn't have the thickness to withstand a typical summer anymore whilst maintaining 6 or 7 milliom km2 of ice.

Any recovery is going to be long term, whereas a complete summer melt out (less than 1 million km2) could happen within the next few years. I don't see where the recovery is gonna come from unfortunately.

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First signs of the arctic winter night approaching at 80°N in the photos of the USCGC Healy http://icefloe.net/A....php?album=2012

Not much ice however.

Also barely light early afternoon at the ice cams now.

http://psc.apl.washington.edu/northpole/NPEO2012/WEBCAM1/ARCHIVE/npeo_cam1_20120912133615.jpg

http://psc.apl.washington.edu/northpole/NPEO2012/WEBCAM2/ARCHIVE/npeo_cam2_20120912125139.jpg

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What would we need for a good quality refreeze?

Would a delayed freeze actually aid in thicker ice formation later due to a deeper layer of mixed cold water forming without being insulated by a thin layer of ice?

The SW winds to the far east of greenland for much of last winter really didnt seem to give us a good pack, however I cant see that a north airflow would help either due to transport through Fram or just transport out of the basin?, Maybe overall light winds here or some southeasterlies which no doubt would be very rare for any prolonged time? I know that a big hight tends to like to settle over greenland presumably due to it having the coldest temps and thus sinking air which generally aids in helping transport through Fram.

Increased precipitation over the basin during a refreeze? Thats gotta be a plus surely?

Volcanic events? Nothing substantial for this year? (if there was it surely would have reduced temps during melt season)

Dipole and jetstream, Higher lat stronger jet, anyone? Is this likely this winter?

Just throwing some ideas around, It would be nice if people could give their views on refreeze factors and magnitude so we can look out for either good or bad signs for this coming refreeze.

This paper entitled "Surface energy budget over the central Arctic Ocean during late summer and early freeze-up" examines in detail the energy flux during refreeze - http://www.agu.org/journals/jd/v106/iD23/2000JD900083/2000JD900083.pdf

Basically it confirms what might seem obvious, the amount of cloud cover, windiness and warm advection, and the proportion of ice to open water determine the radiation balance and refreeze in an area.

However the increase in open water in summer is leading to the year round storage of solar radiation giving a near surface temperature maximum (NSTM) which can melt ice from below even in winter, as described in this article "Winter sea-ice melt in the Canada Basin, Arctic Ocean" - http://www.agu.org/journals/gl/gl1203/2011GL050219/2011GL050219.pdf

Guessing it is possible that a stormy cold period and delayed refreeze could reduce the NSTM but then the freeze period is reduced. If the ice forms earlier, subsequent storms can erode the summer halocline and extend the surface mixed layer into the NSTM and melt the ice or at least reduce its thickness. Bit of a catch 22.

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Looking at the 31 day NATICE animation, it can be seen that the ice pack has gained a little (extent). It has made some gains towards Siberia.

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Despite some adjustments of previous days, we're now on 2 days of SIE increases on the IJIS site, totalling about 65k. I think we may well see the minimum called here soon.

The main minimum call is at the NSIDC though. If we see another significant increase today, I think a minimum announcement by weeks end is likely.

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The Arctic basin is busy in the process of 'normalising' to the type of ocean more typical on the planet. The GAC12 that came through in Aug showed us that the beginnings of the change is well underway and will take a lot of undoing before we again have an ocean capable of carrying the ice load it used to. with some buoys noting mixing as far down as 500m you have to wonder how long before we have a fully operating 'normal' ocean with the Atlantic Deep waters able to mix freely with the layers above (and keep ice free all year round)?

Oceanographers tell us that the heat to keep an ice free basin is already within the ocean but 'the old Arctic' kept a lid on top of this reserve due to it's 'quiet' nature. The more stormy the basin gets with low ice cover (no dampening out of the wave action) the quicker we will see the basin regain it's 'normal' status.

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September chill; Arctic Sea Ice bottoms out; increasing again

Posted at 8:29 AM on September 18, 2012 by Paul Huttner

  • 2.23 million sq km - coverage of Arctic Sea Ice Saturday
  • 2.27 million sq km and growing... Arctic Sea Ice Monday

http://minnesota.pub...c_sea_ice.shtml

113%20asi.PNG

113%20asi2-thumb-490x364.png

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The Arctic basin is busy in the process of 'normalising' to the type of ocean more typical on the planet. The GAC12 that came through in Aug showed us that the beginnings of the change is well underway and will take a lot of undoing before we again have an ocean capable of carrying the ice load it used to. with some buoys noting mixing as far down as 500m you have to wonder how long before we have a fully operating 'normal' ocean with the Atlantic Deep waters able to mix freely with the layers above (and keep ice free all year round)?

Oceanographers tell us that the heat to keep an ice free basin is already within the ocean but 'the old Arctic' kept a lid on top of this reserve due to it's 'quiet' nature. The more stormy the basin gets with low ice cover (no dampening out of the wave action) the quicker we will see the basin regain it's 'normal' status.

This is an interesting subject but there is little evidence at the moment to suggest that this is going to happen in the near future. The Arctic ocean has factors in its favour which tend to preserve an equilibrium eg. the main stratification processes occur in winter so would need to see big changes in freezing at that time of the year; it is 1% of oceanic volume but has 11% of river inflow - fresh water = stratifcation; warming melting Greenland - fresh water = stratification; warming giving more precipitation - fresh = stratification.

By the time the Atlantic water reaches the eastern basins it is far from the surface, below Pacific waters.

Obviously this is not to say change hasn't and isn't happening and the processes are not completely understood.

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Sea ice extent for September 17 was 3.41 million square kilometers (1.32 million square miles). Weather conditions near the ice edge heavily influence the timing of the minimum, which has occurred as late as September 23. We are now five days past the 1979 to 2000 average minimum date of September 13. The decline has slowed in recent days and the minimum will likely be confirmed any day now.

The current extent is 760,000 square kilometers (293,000 square miles) below the previous record minimum extent in the satellite record (4.17 million square kilometers or 1.61 million square miles) which occurred on September 18, 2007. This difference is larger than the size of the state of Texas. The ice extent currently tracks nearly 50% below the 1979 to 2000 average minimum extent.

N_daily_extent_hires-350x417.png

http://nsidc.org/arcticseaicenews/

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Looking very likely that we've passed the minimum, after a 79k increase on the NSIDC extent yesterday, to give a a 145k increase over the last 2 days.

I'd say an official minimum announcement will be made either Friday or Monday.

post-6901-0-38560300-1348065269_thumb.jp

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That is good news. Hopefully any further losses will be offset by bigger gains from now on until we get into the depths of Autumn.

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USCGC Healy at 81°N ice report from 1200 synop shows first mention of freezing - "ICE 57//3" where 3 = ship in easily penetrable ice; conditions worsening.

Temperature below -7°C at the moment.

The ship Polar Stern also mentioned conditions worsening at yesterday with "ship in ice difficult to penetrate; conditions worsening. Ice under slight

pressure" but they are right in the pack near the pole at 87-54N. Temperatures around -4°C.

edit: Incidentally there are some quite nice pictures from the Healy at the moment in a period of extended twilight -http://icefloe.net/Aloftcon_Photos/index.php?album=2012

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Surprised this hasn't been mentioned, but it looks like we've already got our first century increase on IJIS, with a jump of 120k

post-6901-0-65246000-1348144571_thumb.jp

Will be interesting to see if NSIDC follow suit...

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Its going to be a long hard slog if we keeping getting temperature anomalies lie these

post-2495-0-80418400-1348148108_thumb.gi

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Its going to be a long hard slog if we keeping getting temperature anomalies lie these

Generally across the Arctic ocean over the last few years, September, October and November have seen very large surface air temperature anomalies as the reduced ice cover allows heat to build up in the ocean during the Summer, which gets released into the cooling atmosphere during Autumn and early Winter.

That extra heat will reduce the temperature gradient to the tropics, contributing to a more buckled jet stream, allowing for extra warm ridges into the Arctic and cold plunges into the mid-latitudes.

Surface Air Temperature Anomaly September-November, 2007-2011

post-6901-0-57863200-1348148844_thumb.pn

So far this year doesn't appear to be any different

Same as above, but for the first 15 days of this month.

post-6901-0-76516400-1348149100_thumb.gi

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