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Messages - Cato

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Arctic sea ice / Re: IJIS
« on: August 22, 2017, 10:29:43 AM »
Guys, sometimes the easiest explanation is the most reliable: it's the principle of the Razor of Occam at the end of the day. The summer has been rather cool over the arctic and this is fact. There was no significant pre-conditioning, and this is another fact. The synoptic configuration has been quite benign so far, and this is another fact.

For a couple of months I've been stating that synoptic configuration was favorable to ice preservation: lack of strong winds, plenty of clouds in July and August, lack of significant cyclones at the end of August. Nobody should really be surprised by a slowing down of the melting rate in this period.

I think that nobody is immune to confirmation bias: we all know that the trend is clear and is to ice decrease both in extension and volume. This doesn't imply, however, that every year, and every month of that year, there will be a new record-low, or an exceptional melting or something has never been seen before.  2013 should have thought us something in this regard. As Neven has explained very well, 2017 has just dodged a canonball. There is no such thing as "hidden warming", forest fires or whatsoever: summer 2017 has just been very benevolent to the ice in terms of weather and temperatures, that's it. But the trend is clear and is to the low.

Whatever the end of this race, be it a 2nd place or a 5th place, this is not going to change anything in the long term, unfortunately. Which is the only thing that really matters.

Arctic sea ice / Re: IJIS
« on: August 21, 2017, 12:18:49 PM »
No way in my humble opinion a process like ice melting going on for months can be stopped due to some smoke. In theory, one effect of forest fires is that black soot particles are deposited over the ice thus leading to extra-melting (reduction of albedo). But overall, it is obvious to expect that clouds are much more effective than smoke itself in reducing radiation. And clouds have never been missing in the last few weeks, thus helping to contain the melting.

IMHO the factors which helped avoiding a catastrophic melting have been the following: 1) Cloudy weather 2) Lack of GACs 3) Lower-than-average temperatures in July and August 4) Lack of pre-conditioning due to snow accumulation.

Not necessarily does this flattening of the curve anticipate an imminent and anticipated minimum. On the other hand, the synoptic configuration doesn't look like a catastrophic decrease in ice extension is to be expected, apart for some further and physiological compaction over the CAB. The season is almost over, and even a strong LP wouldn't make such a big damage in a couple of weeks' time, as temperatures are going to decrease significantly and precipitations would be mostly in the shape of snow.

Arctic sea ice / Re: IJIS
« on: August 05, 2017, 10:19:32 AM »
Lots of compaction due to the action of rather strong winds from bering towards caa and cab. One or two more days like this, then dispersion should gain momentum IMHO. Interesting end of season I do quite agree.

Arctic sea ice / Re: IJIS
« on: August 01, 2017, 05:48:01 PM »
Thanks Shared Humanity for your interesting post. IMHO the LP will not significantly impact the ice extension as it is forecast to affect an area where ice is rather compact. 2012 ice conditions were terrible at this same time over Beaufort and Chuckhi, and more vulnerable as a result.

Generally speaking I don't expect a major ice extension decrease in the next 7-10 days based on the synoptic configuration.

Arctic sea ice / Re: IJIS
« on: July 24, 2017, 11:07:41 PM »
Hi guys I don't think a -10 k makes such a big difference honestly. If we think in terms of average decrease, I guess the last 10 days have seen an average decrease of about 90 k which is not surprising at all if we consider the synoptic configuration and the average temperatures on the Arctic. Temperatures have been in line with the average or below for the last 3 months almost.

As I stressed in previous posts, it's difficult to get better synoptic charts than the current ones at this moment of the melting season: plenty of clouds, dispersion and not too deep LPs are extremely beneficial in terms of ice preservation. In the next days we will see a more intense intake of warm winds from Pacific Ocean which will be bringing more clouds and precipitations as well.

Difficult to make forecasts at this point of the season honestly. But so far the synoptic analysis has worked quite well. In my very humble opinion, close as we are to the end of July, I believe the momentum for a major melting has probably been lost. But it's nothing more than an barely-educated guess...Just need to wait and see, there's not so much more to wait actually...

Arctic sea ice / Re: IJIS
« on: July 21, 2017, 10:59:34 AM »
Fully agree with Neven's point about the impressive extent decrease in spite of cooler-than-usual conditions over the Arctic for quite a few weeks so far.

I guess the next 10 days will decide most of the final outcome in terms of minimum extent: conditions will be cool, cooler than today, with significant areas of the Arctic below 0C and associated snowfalls. No significant inflow of warm air is forecast, just some quick "injections" of warmer and wetter air from Pacific due to the H+ block forcing LPs to enter the Arctic, a typical late-summer synoptic pattern.

Regarding precipitations I'm attaching the maps of accumulated snowfalls over the next 6 days (ECMWF). Wait and see, it's an exciting end of melting season indeed.

Arctic sea ice / Re: IJIS
« on: July 17, 2017, 05:49:13 PM »
As I expected, the trend is now showing early signs of a slower decrease rate. The synoptic configuration for the next 7-10 days is definitely not bad for the ice. Yet, if confirmed by the next few runs, it would lead in my opinion to a further flattening of the curve. The maps are quite interesting indeed: persistence of LP systems in the absence of too big gradients. In other terms, conditions conductive to ice scattering and preservation due to cloudy skies, some precipitations and no inflow of warm winds from lower latitudes....
The chaps on the 2017 melting season thread have a totally contrary view on the way things are going. I also have looked at various weather sites and have seen nothing to tell me that climatic conditions are going to change soon to promote increased melting.
I agree here

Guys, I'm not an expert in sea-ice, and therefore I'm very reluctant to make my point in front of so many experts in the field, writing on this great forum. If the chaps you are making reference to are basing their analysis on the conditions of the ice, well, I don't have the basic knowledge to oppose their view.

But if their analyses are based on synoptic configuration only, well, I can very well reinstate my point and confirm that weather conditions (based on the current model runs) are not conductive to melting. Or better, to bigger-than-average melting. Those maps are very clear to me. It is difficult to get better conditions for ice preservation than the ones depicted in the latest runs.

Even the temperature forecasts at sea level (though quite variable from run to run and not so reliable in general) show a clear temperature decrease over rather vast areas in the next few days. And it's not so normal (especially in this extremely warm period we're living in) to see below-zero temperatures over rather vast areas as you can see from the latest model runs.

And then, as usual... only time will tell.

Arctic sea ice / Re: IJIS
« on: July 17, 2017, 11:55:26 AM »
As I expected, the trend is now showing early signs of a slower decrease rate. The synoptic configuration for the next 7-10 days is definitely not bad for the ice. Yet, if confirmed by the next few runs, it would lead in my opinion to a further flattening of the curve. The maps are quite interesting indeed: persistence of LP systems in the absence of too big gradients. In other terms, conditions conductive to ice scattering and preservation due to cloudy skies, some precipitations and no inflow of warm winds from lower latitudes.

This is even more relevant in consideration of the fact that this is a key moment of the melting season and "fresh" conditions now would probably determine the outcome of the whole melting season.

Arctic sea ice / Re: IJIS
« on: July 13, 2017, 02:12:33 PM »
IMHO the weather forecasts are all right for the ice in the next 7-10 days. With the obvious premise that they need to be confirmed in the next runs. Lots of clouds, some precipitations, low-gradient LP systems... Considering that this is the most challenging period for the arctic ice, if today's runs are confirmed, I  would tend to be optimistic about 2017 minimum. Moreover, temperatures have been normal or slightly lower than normal for many weeks so far, which obviously helps.

I would not be surprised if 2017 didn't end up in the top-three. But only time will tell.

Arctic sea ice / Re: IJIS
« on: July 10, 2017, 11:48:50 AM »
As I expected, the decrease rate has slowed down due to an anticipated melting in the Hudson in the previous weeks. Fully agree with Neven that next few days will be conductive to melting especially on Beaufort and Chuckchi due to very warm air being sucked-in from the Pacific.

On the other hand, it seems to be a relatively quick event, as a huge LP with low gradient is going to settled down after about 72 hours, a condition relatively beneficial to the ice. Let's see what happens... I expect a few days of century declines followed by a new flattening of the curve.

Arctic sea ice / Re: IJIS
« on: July 05, 2017, 03:52:41 PM »
Interesting the extremely low extension of ice in Hudson compared to the average. This could help flatten the curve in the next few days, considering also that synoptic configurations seem to be rather benign (to the ice) so far... Wait and see, as usual...

Arctic sea ice / Re: IJIS
« on: June 18, 2017, 10:56:01 PM »
Jim, it's the difference between being contrarian on the stock exchange and dilapidating your savings at the casinĂ² I guess ;D

Arctic sea ice / Re: IJIS
« on: June 18, 2017, 11:25:21 AM »
I like contrarian strategies on the stock market therefore I agree with feeltheburn :) synoptic configuration has changed significantly and current conditions are much more favourable to ice preservation. Melting ponds evolution is quite encouraging as well.

Record lows remain the most crowded trading by far, but real big money is made on unpopular tradings :) :)

Arctic sea ice / Re: IJIS
« on: June 01, 2017, 10:42:03 AM »
A "normal" start of melting season I'd say. Where "normal" refers to the last decade unfortunately. I'm not too much impressed by the performance so far: 2017 is not leading for the moment, but this does not imply that the melting season will be gentle with the arctic ice, as we all know. The volumes are small and this is just worrying.

The extension has been sustained by colder-than-usual conditions over the Barents which as usual have been associated with transport. The synoptic conditions have been fairly decent so far: the persistence of HP systems have prevented inflow of warmer and more humid air from the oceans. But in June this pattern can be associated with melting in-situ and formation of melting ponds, and therefore a "gentle" start of the melting season could turn easily into something much less gentle unfortunately.

It looks like in the next few days LP systems will start entering the arctic and persisting. This could help with temperatures as a persistence of the HP pattern in June would have compromised the rest of the season due to pre-conditioning. At least in my humble opinion.

There's a whole story to be written. I guess it will be the usual story of decreasing ice extent and volume, but so far there are not especially worse conditions than usual in terms of snow cover, synoptic patterns and even sea surface temperature (positive anomalies on Barents have decreased significantly). If it is true and evident that the ice is thinner, on the other hand a higher extension would help in terms of albedo, especially on the Beaufort sea, compared to one year ago.

Let's see what happens in the next few weeks. A cloudy June could avoid a major disaster in terms of ice melting, fingers crossed...

Arctic sea ice / Re: IJIS
« on: April 04, 2017, 09:52:24 AM »
Fairly normal in my view: ice extension deficit was concentrated over peripheral areas like st Laurence bay or okhotsk where typically ice melts very early. Which explains why we're now 3rd in the ranking, with the additional dispersion over barents after the unusually cold conditions in the past two weeks.

This melting story is all to be written and as usual synoptic conditions over the arctic in May will be essential to make an educated guess about what is to come in the next few months...

Arctic sea ice / Re: IJIS
« on: February 28, 2017, 11:01:51 AM »
It's a really mixed situation: if on the one hand the (probably) umpteenth lowest maximum just confirms a trend which is crystal clear in itself, on the other hand significant reduction of export from the Fram, very low temperatures over CAA and Beaufort and thicker ice transportation towards Beaufort and Chuckchi are good news for arctic ice in realation to the incoming melting season...

Arctic sea ice / Re: IJIS
« on: February 27, 2017, 11:31:07 AM »
As anticipated in my previous post, extension has come to a stop due to a less favourable synoptic configuration over several peripheral areas of the Arctic. In particular, compaction is ongoing in the Fram (thus reducing export which has been massive in the  last few weeks). Okhotsk is experiencing very mild conditions, and it will just get milder in the next days. Barents does not show much potential for extension increase as well. Therefore I would not be surprised if the maximum had already been reached last week, in line with my expectations.

On the other hand it is worth mentioning that temperatures have significantly decreased over the Arctic. Ice temperature, in particular, in the last few weeks has been significantly lower than one year ago over vast areas of the Arctic, in particular CAA and CAB. Conditions will be extremely cold over CAA and part of Beaufort for the next 7-10 days, thus helping with ice thickening especially in areas like Beaufort where thickness is currently very low.

IMVHO in spite of a one more record-low maximum possibly already achieved, synoptic conditions are not the same unfavourable in terms of distribution of multi-year ice and thickness over critical areas of the Arctic. Of course summer weather conditions will be key to any outcome, including a new summer record-minimum, which remains highly probable in my view. But there are also reasons for a quite cautious and moderate optimism which I'm not willing to disregard.

Arctic sea ice / Re: IJIS
« on: February 20, 2017, 10:22:30 AM »
I wouldn't be surprised if the maximum was made in the next one-week time. It would be another low maximum, needless to say. Bering is getting warmer every day from now on, and Barents will get milder in a few days as well. Potential for ice growth only for Okhotsk and some dispersion in Davis / Newfoundland. Temperatures will be low over the CAB and especially CAA, where increased ice thickness could delay the NW passages opening this year. A lot of transportation ongoing through the Fram, and for the next 4-5 days.

Arctic sea ice / Re: IJIS
« on: February 15, 2017, 11:42:23 AM »
Everything as per the forecasts which, by the way, confirm very low temperatures in Bering, and persistence of low temperatures over Barents as well, where there's space for major extension increase after persisting conditions favourable to compaction in the last weeks. What is more, temperatures close to the seasonal average values will persist over much of the arctic for th next 7-10 days (which is a big news, considering the current trend..)

As usual freezing comes with dispersion, amplifying the overall effect. There's a price to pay though, as transportation through the Fram will probably be massive, due to the combination of persisting strong winds and presence of thick ice north of the strait.

Summarising, I don't see 2017 ending up with a record-low maximum, but in the meantime I remain pessimistic about the overall status of arctic ice, considering the massive volume deficit shown by PIOMAS.

Arctic sea ice / Re: IJIS
« on: February 13, 2017, 02:48:37 PM »
As anticipated by Neven, very cold conditions forecast for Bering for the next 7 days or so. Colder over Barents as well. There's space for a significant extension increase in the next days. Honestly I wouldn't be surprised at all if 2017 maximum was not a new...minimum.

The real issue is about volumes though.. As we've seen from the PIOMAS the situation is just horrible. Temperatures have been "less abnormal" than usual over the Arctic for the last few weeks, and for the next few days there will even be lower-than-average temperatures over several areas, due to a compaction of the PV. Just hope that this will help increasing the volumes over beaufort, Chuckchi and ESS which would somewhat help during melting season.

It is worth noting that there is much more ice in the NW passages than one year ago, as the ice is significantly thicker up there. Winter temperatures have been fairly normal over that area, and they'll keep being low in the next days (between -35C and -42C currently). Just a few drops of good news in a sea of bad ones.

Arctic sea ice / Re: IJIS
« on: February 07, 2017, 03:08:58 PM »
Conditions favourable to compaction in Barents persisting until the end of this week, followed by general cooling. Increasingly colder on Chuckchi and Bering in the next few days, with associated ice extension increase. Very cold over CAA and Beaufort for the next few days.

In this period I'm more interested in the effect of synoptic conditions in terms of ice surface temperature, rather than ice extension. As we've seen from Neven's PIOMAS outlook, IMHO the biggest issue is not just with ice extension but rather with volumes which are really terrible. Cold conditions over the arctic are vital to accumulate some more reserves with a view to the incoming melting season, much more than a few kmq of more extension in peripheral areas which will melt down at the first ray of sun.

Arctic sea ice / Re: IJIS
« on: January 31, 2017, 11:45:24 AM »
Just to be clear, do you think there will be a drop sometime in the next 7-10 days, or that the total extent figure 7-10 days from now will be lower than it is today?

Hi Greg, it's just an educated guess, but I wouldn't be surprised to see a total extent figure lower than the actual, in 10 days' time. The split of PV is really massive and, if on the one hand very cold air will be moving to Canada, the USA, Russia and Europe, on the other hand very big areas of the Arctic will be affected by warm air advection from Atlantic and Pacific side.

In particular, southerly winds will be blowing over Barents for quite a few days, at least 7 days starting from tomorrow, due to the concurrent action of a very active LP in northern Atlantic, and the opposition of a Scand+ high pressure system. The ice recently formed in Barents will be easily compacted and moved northwards with significant extent reduction in that area.

Also Bering will be heavily hit by an advection of warm Pacific air due to a strong HP system in Alaska, even though temperatures will not be exteremely high due to thermal inversion. And Okhotsk will not be any better, due to the action of LP systems bringing warmer air, winds and rough sea conditions.

The only sectors which will remain cold are the CAA, which has been rather cold for quite some time so far, and the coast of Newfoundland and Davis Streit, but I can't see how this could reasonably offset the massive atlantic advection over Barents and the growth slow-down in the other sectors.

Arctic sea ice / Re: IJIS
« on: January 30, 2017, 01:52:18 PM »
Very unfavourable synoptic conditions for arctic ice in the next 1-2 weeks due to a major split of the PV and inflow of warm air from both Pacific and Atlantic. Warmer on Okhotsk as well. I expect a  reduction in ice extension over the next 7-10 days.

Arctic sea ice / Re: IJIS
« on: January 25, 2017, 02:35:41 PM »
In the next few days there's space for some further upside in the okhotsk and bering area, and barents as well starting from tomorrow. In one week time, though, major changes in the synoptic configuration could bring warmer air to the pacific side and barents as well, with the polar vortex more active on canada-newfoundland: a configuration which is especially negative for ice extension.

I agree that volumes and thickness are more important now than extension, which provide limited information on the overall condition of arctic ice.

In particular, it is interesting to note that so far winter has been warmer than usual on Hudson and Newfoundland, and colder than one year ago on CAA and Beaufort, when the gyre was very active.
Distribution of ice shows thicker ice in CAA, CAB and part of Beaufort and ESS, and thinner in Chuckchi. Thinner ice on Hudson as well. Overall, apparently, a more favourable distribution of ice thickness compared to one year ago, even though transport from the Fram seems to be much more relevant this year.

As usual, only time will tell.

Arctic sea ice / Re: IJIS
« on: January 21, 2017, 11:15:25 PM »
If only someone made the effort of reading my previous posts before raising discussions about the meaning of the word "recovery", so many words would have not been spent uselessly. "This of course does not challenge the long term trend, which is quite clear. But I would not be surprised if there was a temporary recovery in ice extension and volume, from now on and for the next one-to-two years." I thought this sentence was clear enough. Recovery to me means, for example, passing from the last position to the second-last. Is that clear enough now? It's honestly tiring sometimes, and disappointing being forced to add a disclaimer to any discussion like "I don't mean to say that ice won't disappear, or the like". And references to tea parties and Fox news then... For an Italian like me :)... it sounds just like complete and unwillingly funny nonsense.

I'll take Neven's request to close this senseless argument and focus on more sensible issues. I have the greatest respect for his work, his professionalism and intellectual honesty as I've been following his blog for the several years, and I beg your pardon if my post led someway to this senseless off-topic discussion. It was not my intention.

Regarding the recent JAXA extension increase, I maintain my opinion that with such low temperatures in Bering area, freezing is just what one should expect. There's -25C in Savoonga and -27C in Mekoryuk as we speak. Dispersion IMHO is in most cases associated with cold air advections and therefore it's a difficult and probably useless exercise to try separating the two issues which generally tend to act concurrently. For example, the LP currently forming in the Pacific will activate strong, and cold winds from Alaska to Russia, thus leading to extension increase for both advection of colder air, and dispersion of the existing ice offshore Alaska.

The same has happened recently for Barents, where cold air from the CAB has moved to Svalbard and Kara Sea. Again, combination of two concurring factors: colder air moving southwards and dispersion. The same typically applies to Hudson as well, associated with cold westerlies moving from Manitoba or Nunavut to the Atlantic. There is therefore not much point in justifying the current extension increase with "dispersion" only. Dispersion and advection of cold air just tend to act concurrently in most cases.

Arctic sea ice / Re: IJIS
« on: January 20, 2017, 10:45:26 PM »
I didn't mean to sound revolutionary mentioning that sea gets frozen with temperatures of -25C. I understand, though, that anything which goes against the narrative of the "death spiral" and so on and so forth is seen as a threat. I can't see any threat in mentioning that ice is forming in bering because it's cold, however revolutionary this concept might sound.

Regarding the use of the word "recovery", well, free to choose anything sounding more adherent to the narrative of the dying and hopeless patient, I'm OK with it, honestly. Especially considering I'm not a mother tongue English speaker...

For the rest, I watch the thickness maps from dmi and I see much more ice than one year ago in CAB, CAA, part of Beaufort and ESS. And less ice in Hudson, Chuckchi and Barents. I watch the maps and I see low temperatures and favourable synoptic configurations for the arctic ice in the next 7-10 days, and I feel more optimistic for a recovery... sorry... for a dead-cat-bounce than I was one year ago. And if the Nino has been a hot topic for the last two years, I cannot understand why it should sound so heretic to expect a decrease of temperatures over the arctic now the enso is neutral again.

Arctic sea ice / Re: IJIS
« on: January 20, 2017, 12:21:43 PM »
Barrow -37C, Mekoriuk and Savoonga -22. Not surprisingly ice is freezing in bering. Compared to one year ago, beufort is much colder and this is important with a view to melting in summertime. One year ago el nino was strong, now enso is neutral and temperatures are falling globally as a result. It is quite normal the arctic is getting cooler as well, with a lag compared to land. This of course does not challenge the long term trend, which is quite clear. But I would not be surprised if there was a temporary recovery in ice extension and volume, from now on and for the next one-to-two years.

Arctic sea ice / Re: IJIS
« on: January 20, 2017, 08:03:21 AM »
I see discussions about waves and dispersion.. anybody looking at the temperatures by the way? It's extremely cold in the Beaufort and Bering and it will be extremely cold over the CAB in the next few days. I expect piomas will be veeyextremely interesting in the next release. Sometimes things are much easier than we want to believe. When it's cold ice is formed, and viceversa... ;)

Arctic sea ice / Re: IJIS
« on: December 30, 2016, 06:10:16 AM »
Don't want to anticipate Espen's post, I'll just say that it's gonna be a thrilling ending for year 2016... ;)

Arctic sea ice / Re: IJIS
« on: December 28, 2016, 10:10:03 AM »
And here we (nearly) are. Conditions in Barents have changed: no more compaction and colder conditions forecast for the next few days...

Arctic sea ice / Re: IJIS
« on: December 20, 2016, 10:39:37 AM »
More or less in accordance with the forecast, freezing over hudson has been very quick, though partially offset by compaction in Barents. The gap has not been closed due to the slower than expected (by me) freezing rate over Okhotsk.

Between now and the 31th of December, about 800,000 kmq are needed to close the gap. It's not a big deal as it makes slightly more than 70k per day. And there is potential for further freezing over Okhotsk, Davis streit and Chuckchi, where conditions will be very cold in the next one week. IMHO there is more than 1 million kmq to freeze in those areas, as conditions over barents will keep being extremely warm and favourable to further compaction.

Based on synoptic considerations only, I still tend to believe that 2016 will not be leading by the end of December.

Arctic sea ice / Re: IJIS
« on: December 16, 2016, 12:50:31 AM »
As per the forecasts, Hudson is freezing quickly and there's 5-6 days left of very low temperatures to further increase extension up there. Very cold conditions forecast for the Okhotsk and, in a few days, for Chukchi as well.

There's more than 1 million kmq left to be frozen between Hudson, Chuckchi and coastal areas of Okhotsk and Newfoundland where conditions will be generally cold for the next one week. Part of this increase will be offset by very warm conditions in Barents, where I expect also some compaction after the strong winds from the south.

Overall I keep expecting that 2016 will probably close the gap in about one week time (I'm always overoptimistic, I know...)

Arctic sea ice / Re: IJIS
« on: December 12, 2016, 05:07:42 PM »
Quick increase of extension, as per the forecast. In the next few days the recurring synoptic pattern will be reinstated, with consequent massive advection of warm air from both Atlantic and Pacific into the CAB.

In spite of this, extension should keep growing significantly, for the contribution of Hudson, Ohotsk and the smaller contributions from Davis Streit and Kara (east of Novaya Zemlja).

I confirm my view that by the 20th of December, 2016 might no longer be at the top...

Arctic sea ice / Re: IJIS
« on: December 08, 2016, 03:38:27 PM »
There's no much to say, especially after the latest update from PIOMAS (and the very nice and professional summary by Neven, as usual). On a synoptic level, though, the situation does not appear desperate to me, in perspective. At least with reference to extension.

In the next 7-10 days I expect the complete refreeze of Hudson, which accounts alone for almost 1 million kmq. Moreover, fairly cold conditions will persist over Kara and (partially) Barents, with consequent decrease of positive temperature anomalies, which actually have been decreasing significantly in the last couple of weeks. There's potential for further 0.5 million kmq in the next 7-10 days upd there, IMHO.

With a view to the above, I wouldn't be surprised if 2016  recovered a significant part of the gap with the top years, in the next couple of weeks. Which does not mean, of course, that the patient is gonna be healed, as we all know...

I wanna be optimistic, though, and I'll put my two cents on a recovery of the gap within the 20th of December, however unrealistic this forecast might sound...

Arctic sea ice / Re: IJIS
« on: December 06, 2016, 10:43:12 AM »
Agree with Tigertown: a lot of "effort" has been spent by the Arctic to cool up the waters in Barents and Kara, where positive anomalies have been very high, and for very long time.

So far, the relatively cold conditions in that area have just led to a decrease in the anomaly, but no additional ice. This process will be ongoing for the next few days, about one week, before very mild air is conveyed up there by the LP systems developing in the Atlantic and moving NE.

In the next days, though, a significant contribution to ice extension will be provided by Hudson, where conditions will turn extremely cold after the collapse of the polar vortex over North America. There's about 1 million kmq to freeze in Hudson, and they're coming soon.

Arctic sea ice / Re: IJIS
« on: November 22, 2016, 11:00:28 AM »
...As per the forecast I guess  ;) Synoptic configuration has changed dramatically up there, and a very cold HP is due to persist for quite a few days. Easy to foresee a quick recovery in the Kara Sea and a general cooling overall. Okhotsk is colder than usual and will keep being cold in the next days, while Hudson is warmer. There's a long way to go before reaching 2006 but at least there looks to be some competition now...

Arctic sea ice / Re: IJIS
« on: November 17, 2016, 10:56:23 AM »
Hi everybody, always reading this thread: one of my first-things in the morning. I would just like to highlight one issue that IMHO is very important and very well explains what is happening up there: there's been for quite a long time, several months actually, an anomalous persistence of HP in the north Pacific sector, namely in the Aleutian islands area.

This has enabled advection of very warm and humid air into the Arctic from the Bering strait. In summer, this has been the main reason for cloudy and stormy conditions in the Arctic, and for ice compaction towards the CAA. This trend has continued, leading to unusually warm air being pumped in the Arctic from the Pacific, which is happening right now actually, with the umpteenth advection of warm air from Bering and slowdown in the ice extension growth rate (if any at all!). The other side of the medal is the extremely cold conditions in Siberia, which are affecting an immense area, from Russia down to Mongolia and Kazakhstan.

It seems (!) that this synoptic configuration is changing in the next few days, with collapse of the HP blocking in the Aleutian and establishment of a very cold HP on the Artcic. This will lead to a collapse in arctic temperature and an increase of the ice growth rate accordingly. Far from suggesting that what is happening up there is "normal". It is not, definifinitely.

My point is, rather than pointing the finger only at the unusually high temperatures on the arctic, it would quite help to have a look at the synoptic configurations. This helps a lot understanding why it is so warm, and whether this anomaly is going to persist. IMHO we will see soon a significant change in the conditions up there. Too late to recover what has been lost? Probably yes. But at least, it will add some more drama to a movie that is getting too repetitive, isn't it?

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