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Just Testing

Isn't this an expansion of the stable high-pressure zone over Greenland that was discussed last year? The one that first reared its head in 2007. The same that is arguably responsible for the U.S. drought? The one that's been dubbed the "climatological north pole"?

If so it looks like it's here to stay and emerge for an extended period of time each year.

wayne

Just testing, Greenland always had a near permanent Anticyclone over it, going back to the first days of world wide meteorology.
The jet stream patterns surely were affected by a new source of heat from below, the thinner ice and multiple leads gave strangely
anticyclone stability at least for this past winter.. Very unlike the winter before.... I attribute all this to thinner and thinner ice and especially what remains of the thick pack. Last winter remnant pack was just North of CAA to the Pole. This created a natural High, adjoined by surrounding Lows caused by open water all around it at minima last September. The Arctic weather pattern for last winter was thus set, with NE winds following the CAA coast, and NW winds parallel to the Northern Siberia coast. With long night time and way above, the stratospheric vortex became significant by end of December 2012.
Only to collapse in January. Causing 2 vortices, the CAA and Siberian one. In synchronized tandem with the old Ice pack centred circulation from earlier winter. This pattern dominated the rest of winter 2012-2013. Every year has a different circulation style because the field of sea ice cover morphed and looked different one winter to next. I expect a different pattern next winter as a great sea ice melt looms. If it happens, an absent significant core of old sea ice will cause even more surprises. Greenland Natural High will be consolidated around what will be left of the sea ice pack, rather than hovering about the larger Arctic Ocean. This will mean cooler NW Europe for part of winter and much warmer  Canadian Arctic with consequences we have a good idea about further South.

Christoffer Ladstein

In Norway we have to go back to 2006 & 1987 to come a cross a March more severe than this year. Interesting then to compare Ilulissat, situated at the middle of coastal western Greenland (in the Disco bay. They will most likely, as the attached web link will show, witness a March more than 10 C warmer than the normal (1961-1990), and in 2006 it was even more extreme...
http://www.dmi.dk/dmi/vejrarkiv-gl?region=3&year=2013&month=3

So what else than different Jetstreams cause this, and is the Jetstream really so linked to the "position and amount" of Arctic ice?

Susan Anderson

I'm in the US northeast and we too have been in the zone on this one. The storm that just passed is humongous. Every time somebody thinks this can't be happening so fast there's more evidence.

I understand there was a second SSW event; Tenney sent me this:

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/hgt.shtml

And I've posted this before, but for a short clear obvious explanation with helpful animations, it's hard to beat:
http://www.bbc.co.uk/weather/features/20998895

R. Gates

There are certainly two dynamics at play in the "weirding" of this winter's weather, but before discussing them, it would probably be good to understand that we are in a new regime of climate and therefore weather patterns, and thus, the weather is only weird compared to some former regime. In other words-- weird is the new norm, and it will be weird in the future not to have blocking patterns and associated extremes that come with climate change.

But back to the two big dynamics at work in this winter's NH winter. The first is of course the big SSW event that took place in early January. This event was not unlike the big SSW events of 2009 and 2006. The polar vortex was shattered and the normal westerlies over the Arctic reversed and cold air from the east has been generally circulating over N. Europe for several months. The SSW event from January, in addition to breaking down the vortex and warming the stratosphere over the Arctic, brought downwelling air actually all the way from the mesosphere down into the stratosphere and created higher pressure all the way down to the troposphere. This downwelling air from the mesosphere also affects stratospheric chemistry such that we've seen some of the lowest ozone levels ever recorded over the Arctic in the stratosphere this March. But more than that, the downwelling air (that began during the SSW of early January) lead to an AO index that fell well below -5, a level never before seen in over 60 years of records. In short, the SSW event from January has had lingering repercussions far beyond the original rapid stratospheric temperature spike. One must keep in mind that the energy or initial trigger for this event begins as an upwardly directed pulse or wave of warm air that begins far south of the Arctic in the troposphere, where it pulses rapidly up into the stratosphere and then travels at mid and upper stratospheric levels before descending rapidly over the pole. The SSW of January over the Arctic had its energetic origins over south Central Asia in December.

But the other influence in this winter's weather is certainly the low sea ice level, and with it, the changes in atmospheric circulation in general that Dr. Francis and others are studying so closely. It might seem natural to try and associate SSW events and the atmospheric changes brought about sea ice decline but there doesn't seem to be a link. However, that does not mean that they might not have some synergistic interplay. For example, if you get a blocked atmosphere as the result of lower sea ice (and the resultant change in thermal gradient between equator and pole) and an SSW event does come along, that blocked atmosphere could enhance the effects of the SSW, i.e. the two combined could certainly result in exactly what we saw a few weeks back with an AO index that was off the (bottom) of the chart, literally.

R. Gates

Regarding the easterly wind anomaly over higher latitudes of the NH that began as part of the January SSW event, this chart shows this quite clearly:

http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/gif_files/time_pres_UGRD_ANOM_JFM_NH_2013.gif

The easterly anomaly began with the SSW event and has brought colder Siberian and Arctic air masses consistently from the east over Europe since Janauary. The higher pressure over the polar regions also had its origins with the January SSW event:

http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/gif_files/time_pres_HGT_ANOM_JFM_NH_2013.gif

If SSW's are not caused by lower sea ice, but their effects are potentially enhanced by them, then we would expect more extreme effects from SSW's in future NH winters as alterations in the jet stream and blocking effects from lower sea ice levels enhance SSW effects.

Finally, the very low AO, which coincided with the cracking of MYI as reported so well by A-team and others, may certainly be one example of the an enhancement of January's SSW effects. The descending air and higher pressure over the Arctic brought about a stronger anti-cyclonic rotation of that lasted over a longer period. This is the same easterly anomaly as discussed and linked to above. The ice may have been primed to crack by being thinner anyway, but the sustained high pressure and anticyclonic action worked over a long period and helped to enhance the cracking in my estimation.


Werther

Thanks, R.Gates,
Your summary of last winter fits nicely to what I´ve been following, but haven´t been able to show in graphuics )yet+ I tried on the Forum...).
The part that really gets to me is the possible teleconnection(-s). You discreted well between the low sea ice effect and the SSW events.
My alarmist concern is that at 400 ppm CO2 and accompanying, though lagged feedback, irreversible change has already occurred in atmospheric/oceanic distribution patterns...

Ac A

Sorry for a bit more philosophical comment by Michael McCarthy, outgoing environment editor of The Independent:

In our current belief system, which we might term liberal secular humanism, which has held sway in the West since the Second World War, and which promotes human progress and well-being, only one response is permitted: Yes, of course! Any suggestion that there might be something wrong with people as a whole, with Man as a species, is absolute anathema. But today, two circumstances come together to prompt me to pose the question once more.

http://www.independent.co.uk/voices/comment/man-is-fallen-and-will-destroy-the-earth--but-at-least-we-greens-made-him-wait-8554548.html

Shared Humanity

Just Testing.....If so it looks like it's here to stay and emerge for an extended period of time each year.

My fear (grounded entirely in ignorance) is the blocking highs that currently form and then disappear with a polar high pressure over Greenland, causing sticky weather patterns, will become more persistent as the arctic becomes ice free and the jet stream will get locked in for extended periods of time. Could we see a persistent weather across the NH and what could it look like?

Alan Clark

An interesting article, but I would like to see what the models predict when the Arctic ice melts even further.
The temperature anomaly near Greenland has been huge recently, so I wondered how unusual it was, and if it had anything to do with the shrinking ice. This answers my question!

Susan Anderson

mildly OT, but does anyone know of a good animation of the jet stream for Europe?

Neven

R. Gates, thanks a lot for those comments! You explain things so well that I've added them to the post.

Neven

Maybe we could discuss the following some more:

the downwelling air (that began during the SSW of early January) lead to an AO index that fell well below -5, a level never before seen in over 60 years of records.

Is this graph below the 60 years of records, because the CPC AO page only has 3 month running or seasonal means:

Here's another one from 2000 onwards:

As you say this latest event had the AO going down to -5.5. The only thing that comes close to it is 2010. In the spring of 2010 we saw that huge drop in PIOMAS volume that Chris Reynolds has been analyzing so much. I wonder if the two are related?

As Chris wrote in his latest blog post on the matter a remnant of thicker ice in the vicinity of the Chukchi Sea (which I called The Arm at the time) prevented a sea ice massacre. In 2011 the massacre was just barely prevented (and the 2007 record minimum was 'only' tied). 2012 looked like it was going to be a repeat, but the ice didn't stand a chance. This year there is no buffer of older, thicker ice.

If this ultra-negative AO is a taste of what happened in 2010...

I don't even want to think about that.

Steve Bloom

Could be a coincidence. Or not.

What are the physics?

Steve Bloom

SH, a lot like what we're seeing now. Those highs like to set up in a couple specific places, then everything else follows.

Glacierchange.wordpress.com

The onset of the January SSW over Asia is depicted nicely in this animation from The Lee Side.

Martin Gisser
If this ultra-negative AO is a taste of what happened in 2010...

I don't even want to think about that.

Why not?

Whammies like in 2010 are alas necessary to wake up folks. The sooner and harder they come, the better. Lets hope that this turn more of the less innocent get hit: Please, not another baking and flushing of Pakistan this time, but what about another Sandy, with a nice flushing of Wall Street? And certainly the environmental and scientific North Korea, i.e. Canada, desperately needs a little blow on the head. I suggest, dear Mother Earth, to turn the vast swaths of bark beetle killed forests into the fires of 2013 (that would sequester a little carbon in form of char - human technologists are to stupid for that). Also me cynic thinks it necessary to hit the Middle East with more drought plus global grain supply shortages: It is time for folks to learn to cope with such things in peaceful collaboration (plus, dear Gaza maternity clinic chef, by Allah, you don't need millions more babies). Peace or perish. And lots of perishing of overshot population is already in the pipeline, this century.

I want to keep a tiny spark of optimism regarding our dismal species. Perhaps Late Homo S Sapiens can indeed learn, and not end up as a monstrous accident of evolution.

But for that we need more and harder 2010s, and soon.

R. Gates

Actually did a closer review of the daily AO data and found that there were a few days the index has fallen below -5 since 1950, though it is a rare event. During early March of 1970 the index fell below -6! Interestingly, in the months preceding that low index there were two major SSW events, as evidenced by the chart on page 165 of this research paper:

http://www.meteo.psu.edu/~fcstmgr/stratwarm.pdf

That paper BTW is an excellent though somewhat dated resource on how SSW's over the pole affect our weather down here at lower latitudes.

Here's the link to daily AO readings going back to 1950, which are better for weather forecasts than monthly means:

ftp://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.ao.index.b500101.current.ascii

Also note that March numbers are not yet reflected in this daily data.

Finally, my general conclusion is that SSW events definitely play a big role in creating the low very AO indexes much of the time, though certainly not all. It certainly was true for 2010, 1970, and this year. Overall though, the progress of weather patterns, wind, pressure, etc over the higher latitudes of the NH this winter seem more similar to 2006 than anything else I can find:

http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/gif_files/time_pres_HGT_ANOM_ALL_NH_2006.gif

Though of course we had much thicker sea ice in 2006. Here the dynamic of the lingering effects of an SSW combined with declining sea ice will be interesting to watch.

R. Gates

Previous link was cut off.

Link to daily AO data:

http://tiny.cc/2uetuw

Chris Reynolds

Neven,

As a large part of the volume loss of 2010 was the loss of thick MYI driven into the Siberian sector I don't think a re-run will occur. Recent events have happened too late for the remnant MYI to suffer the same fate.

I think the tale of this year will centre around First Year Ice and its lower albedo during the melt season.

It's not winter weirdness but my latest blog post concerns Eurasian snowfall and atmospheric impacts.
http://dosbat.blogspot.co.uk/2013/03/eurasian-snow-cover-and-atmospheric.html

Hans Verbeek

Neven, between 1987 and 1996 the AO was more often positive than negative.
Between 1996 and 2008 longterm AO-average was around zero (neutral).
But since 2008 the AO-average is heading towards the slightly negative value seen between 1950 and 1985.

http://cassandraclub.files.wordpress.com/2013/03/ao19502012.jpg

What could have caused the positive AO between 1987 - 1996?
What is causing the AO to return to the normal 20th century pattern?

By the way, the NH-snowcover is still way above normal.
http://moe.met.fsu.edu/snow/nhtime-4month.png

A-Team

"I don't think a re-run will occur. Recent events have happened too late for the remnant MYI to suffer the same fate."

What 'recent events' can you possibly be referring to here, Chris?

The Beaufort avhrr photos show us still running 45-50 days ahead of last spring's Modis series, May has become March. The brittleness and mobility of the remnant older ice is unprecedented in human history. Recently, decades of downward trend culminating in a dramatically lower low in 2012.

You've worked very hard and intelligently on this for a long time ... yet every Dosbat post I've read is the same: a 180º halfway through. Vacillation is not a bottom line. At what point do you think you'll be able make up your mind?

We're looking at catastrophic melt-out by mid-summer. I wouldn't be here otherwise.

Ac A

Hey A-Team,

looks like a critique of Chris. I suggest that Chris would agree that we are seeing "catastrophic" situation in the Arctic (details be damned). I am afraid, we are all powerless to do anything more than to describe this ongoing catastrophe.

Yesterday my friend from Uni studies posted to a Facebook pictures of her 3rd children. I wrote her:

"Congratulations. When she will be at my age (32), your daughter will not experience arctic summer floating ice".

She responded to me:

"Neither did I experience arctic ice and I am quite confortable..."

Even of all people recognize Arctic ice is critical for stable climate/weather, whould would change as a result?

Alex

Robert Fanney

A-Team...

Beaufort is definitely looking a lot weaker than last year at this time. I'm also wondering what's happening late?

Chris Reynolds

Hans,

At the time of the 1990s positive AO there was talk in the literature of it being driven by stratospheric cooling due to the enhanced greenhouse effect. If anyone knows what recent theories are I'd love to know.

Neven
What could have caused the positive AO between 1987 - 1996? What is causing the AO to return to the normal 20th century pattern?

I have no idea, Hans. I don't think anyone really has.

But keep in mind also that 1) AO is an oscillation, it oscillates back and forth, meaning that positive and negative even out in the long run, unless something big changes that, 2) AO is an interesting metric, but it doesn't tell us about important details, such as the position of highs and lows, 3) there's a difference between AO in winter and summer.

By the way, the NH-snowcover is still way above normal.

Yes, it's going to be interesting from April onwards. A positive anomaly from the monthly average would be highly interesting, as it has been 9 years since the last time.

Chris Reynolds

A-Team,

If I seem like I can't make up my mind it's because I'm often faced with too much complexity to be sure.

I still harbour doubts that I may have backed the rapid transition position too soon and something I've missed will cause a large negative feedback to kick in. The ice is very nearly at a totally first year state now, which is why I expect another record this year. But even with this state I do not anticipate a virtually ice free ocean this year. I think there needs to be more winter thinning, which is a symptom of the RILE I think we're in.

What recent events? Well the recent fracturing confirms what we know from ASCAT/PIOMAS and the DAM - there's a lot of FYI out there. But I'm increasingly sure that the pack is not so mobile that the interior remnant of MYI will transit out of that region to any great degree. Looking at past DAM images suggests the ice doesn't move that fast, we're nearly in April and a lot of the movement in 2010 occurred before that time over the winter.

As for March becoming May - you may have a point, but the situation is without precedent, lets see.

I've already been pretty strident over on the forum - if the ice falls below 1M km^2 Extent (NSIDC Daily) or 0.5M km^2 area (CT), I'll give up blogging. I don't want to do it, if I thought there were any chance of it happening I wouldn't have said that.

I'm virtually certain that this year will fall below last year's record, by how much I don't know, but it won't be ice free or below the limits I said in the previous para. Of that I'm 100% sure.

To expand on this I'll just quote from a reply of mine over at the forum - Why less than 1M Extent won't happen:

...what volume does 1M km^2 extent mean? Well extent is a crap metric, how much area is 1M km^2 extent? For 2012 August Dispersion Index was around 1.6, that's NSIDC EXtent / CT Area.
http://www.flickr.com/photos/54059206@N07/8581338180/#
so 1M extent / 1.6 => 0.625M area.

At a finishing thickness for Sept of around 1.1m in 2012: 0.0011*625,000 ~ 700 km^3, lets round that further in your favour and say it only has to get down to 1k km^3. Which gives a closely compacted pack of 1M extent with thickness 1m, any low concentration areas mean you need to lose more volume to get to 1M extent. Given that daily min volume 2012 was 3.261k km^3, this year would need to lose 2.261k km^3 below last year's minimum.

So this year needs to lose 2.2k km^3 more than last year did from max to min volume in order to get to 1M km^2 extent. That's taking into account the extra 1k km^3 spring melt that's already happened due to more FYI since 2010.

Steve Bloom

Late snow means April flooding. Something to look forward to.

Re the short-term ice trend, we, scientists and all, are just guessing at this point. All we really know is that GCM-based projections of a slow process appear incorrect. Maslowski's RCM -based projection may be correct, but just the other day he was lecturing Neven about jumping the gun on this stuff (although to be fair the context was Neven's question was about how soon the Arctic could go entirely sea ice-free).

My personal guess at this point is to agree with A-Team, albeit with large error bars. :)

But I'll repeat again the larger context, which is that the last time CO2 was ~350 ppm for any length of time Arctic temps were 18C +/- 4C greater than present, and the models are unable to replicate this even with varying assumptions about changed boundary conditions. Push on the Arctic and something big happens, and we don't really know what it is. We can't say for sure that we're seeing the beginning stages of a rapid shift toward such a state now, but nor can we say we're not.

Steve Bloom

Alexander, your interaction with your friend demonstrates yet again that many if not most people will be able to make light of even sharp changes in the Arctic unless there are clear, immediate implications that will impact them. So IMO we need to speak in terms of feedbacks that will affect crops via drought, floods and temperature excursions (mainly heat but still some cold, as we are seeing more and more). Europeans and Americans have lost their cultural memory of famine, so it's going to be harder to get them to pay attention.

R. Gates

1987 - Two big SSW events (Jan and Dec. with a negative AO during both
1988 - One SSW in March with a negative AO following into May
1989 - Moderate SW in Feb with negative AO not coming until April. that chart is an interesting one, see:
http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/gif_files/time_pres_HGT_ANOM_ALL_NH_1989.gif
1990 - No major SSW events and no major negative AO periods.
1991 - Odd year. several minor SSW events with negative AO periods, with a major high pressure anomaly in the Arctic stratosphere in the middle part of the year. See:
http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/gif_files/time_pres_HGT_ANOM_ALL_NH_1991.gif
Mt. Pinatubo erupted in June of 1991.

1992 - Moderate SSW in Jan. followed by moderate periods of negative AO.
1993 - Minor SSW in Feb. with minor period of negative AO.
1994 - Moderate SSW in March followed by negative periods of AO in April and May. Those charts are worth viewing to reinforce the direct relationship between SSW events and negative AO's:

http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/gif_files/time_pres_TEMP_ANOM_ALL_NH_1994.gif

http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/gif_files/time_pres_HGT_ANOM_ALL_NH_1994.gif

1995 - Minor SSW in Jan. with period of negative AO.

1996 - Several minor to mderate SSW's Jan to March with periods of negative AO associated.

During the period of 1987 to 1996, overall it looks like the association of negative AO and SSW's holds, but keep in mind that while SSW's might lead to negative AO index, not all negative AO periods are caused by SSW's of course. The most interesting year out of this whole period seems to be 1991, with the big high pressure anomaly in the stratosphere over the pole during the mid part of that year, perhaps related to the eruption of Mt. Pinatubo?

Steve Bloom

Chris, my tendency is to agree with you (those error bars again) about the loss being sharp, but probably not all the way down to the levels you mentioned. On the one hand the ice is overall more vulnerable and I suspect there will be further pressure on the MYI if the FYI disappears early (analogous to how ice shelf loss enhances glacier flow), but the gyre shows no sign of fundamental changes and so will probably save much of the MYI (of which I also agree there is *probably* too much of to melt in place).

This is really all just quibbling as I doubt global climate trends care very much about the exact year in which sea ice levels reach some arbitrary benchmark. What those trends do care about is the rate at which incipient ice-free conditions expand.

But regardless, don't give up blogging on this stuff based on a quibble. Your efforts are too valuable.

Robert Fanney

@ Chris, @ A-Team

My take is that there's a low risk of total melt this year. But there is still some risk. Any melt comparable to 2007 or 2010 (volume) would do it. A 2010-like melt would leave a very small remnant. The fact that this kind of thing is a possibility for this year is a big deal. But I don't think it's the most likely possibility.

Will have to agree mostly with Chris and say it is most likely to be another record low year (volume) and possible for area and extent.

But I also think you can't completely rule out a slight recovery year. Not likely, given all the variables mounted against the ice, but also possible. So, to sum up, more melt is most likely, total melt is possible (never been statistically possible before), and slight recovery (a bump in the ongoing melt trend) is also possible.

Chris -- I wouldn't quit blogging if you end up being wrong. Everyone who makes predictions is wrong at some point. And though your current call is probably most likely, it is possible that sea ice could blow through those low barriers. Not likely but not something worth staking your blogging career on.

A-Team

We've got people here at all the Kübler-Ross stages of sea ice loss -- anger, denial, negotiating, depression, and acceptance.

The first four are different versions of whistling in the dark (recursion to the mean, hail mary positive feedbacks, intervening volcano, clouds, whatever straws people choose to grasp).

I'm looking right now at a 98 day animation of spring 2012 Modis. The 10 May 2012 shot of the Beaufort bears an uncanny resemblance to what I see on the 30 Mar 2013 Modis and avhrr imagery.

We cannot simply add 40-50 days to a 100 day melt season and expect anything less than a complete fiasco. We've had close calls before (almost used bromofluorocarbons) but this time we've really done blown it.

As Martin G notes above, it is all for the best.

Villabolo

@ Steve:

"So IMO we need to speak in terms of feedbacks that will affect crops via drought, floods and temperature excursions..."

A short slogan (which I gave to freewayblogger) might be of help in communicating that thought -

Arctic loses ice, we lose crops.

Kevin O'Neill

I can remember when plate tectonics was a fringe theory. Likewise the idea that an asteroid collision caused the dinosaurs to become extinct. Combine that personal history with the 'fringe' prediction that the arctic could be devoid of sea ice this decade and it's easy to understand why I'm in the Barber/Wadhams/Maslowski camp.

In the grand scheme of things it matters not whether the sea ice extent falls below 1M km^2 this year, next year, or in 2020. It will - this decade or next - and then maybe, *maybe,* there will be enough political will to try and right the ship as best we can.

Anyone with the most rudimentary understanding of the data knows we're seeing changes in the arctic that will have impacts that last for centuries. Not only haven't the brakes been applied to this speeding train, we're still accelerating.

I wouldn't bet on the arctic sea ice falling below 1M km^2 this year - but neither would I bet very much against it. Since it's going to happen within a few years anyways, perhaps it's better that it all go in one big melt/flush to garner the most attention and instill a little backbone into some of our politicians.

Professor Wadhams predicted, "In the end, it will just melt away quite suddenly." I suppose this year is as good as any for that prediction to come true.


Villabolo

@ Kevin:

"...maybe, *maybe,* there will be enough political will to try and right the ship as best we can."

With the exception of some Democrats it is not the absence of political will but rather the presence of moral torpidity - actually psychopathy - that we're dealing with.

The mentality of the elite is such that they don't care what happens to anyone so long as it doesn't happen to them. They'll be able to afford plenty of food and armed guards.

You cannot negotiate with these people. Humanity means nothing to them. We need to root out these people as they will be an active force undermining our future.

Artful Dodger

I agree with A-Team, as I stated here on June 29, 2010:

"The drop in sea ice area is impressive. More impressive is the date it occurred.

The Arctic Basin began its annual melt about 12 days earlier than 2009.
(look at the far left of the Arctic Basin graph).

Earlier onset of melt allows loss of more ice. Later freeze-up allows less to regrow.

When the length of the melt season passes a tipping point, Arctic Basin ice will be unable to recover and we will soon have a seasonally ice free Arctic (I estimate 2013).

If other feedbacks continue to extent the range of melt/freeze dates, we will have a perennially ice free Arctic Ocean (a recent paper said perhaps only decades from now).

Then, when summer SST's reach 28C, we will see Arctic hurricanes. How's that for alarmist?"

The time for scientific reticence has long past. We have entered the period of consequences.

Well, a slight revision to my stance after Aug 6, 2012. I am now aware of the dynamics of both warm-core and cold-core cyclones. Both are heat difference engines.

I expect the cold-core variety to continue until the last cold stores are used up. Then a quick transition in Arctic SSTs, followed shortly by true Atlantic-style warm-core hurricanes in the Central Basin.

The 2012 melt season proved that Summer weather no longer matters in predicting sea ice decline. One only needs a calendar.

Still, we are missing one piece of diagnostic information that would resolve much of the uncertainty in predicting the 1st sea ice-free Summer: Atlantic heat influx. Petajoules lurk therein, but not ignored by the sea ice.

Hint: Until recently, there were 4 ice shelves on Ellesmere Island. They didn't melt from the Sun. Now that they're gone, what is the next coldest sink in the Arctic?

Nightvid Cole

Chris,

As a large part of the volume loss of 2010 was the loss of thick MYI driven into the Siberian sector I don't think a re-run will occur.

I don't think this is right. In the spring of 2008, a whole lot more MYI had been advected into the southern part of the Beaufort Gyre than in 2010, and yet the volume loss that spring and summer was much lower, if we believe PIOMAS.

Something else must be invoked in order to explain the loss of 2010. I suspect it had to do with large April temperature anomalies across the Arctic Ocean in 2010, but without the ability to "tweak" the weather and re-run PIOMAS to see the effect, I cannot say for sure.

Memoryholeblog

To what degree does stratospheric aerosol geoengineering play in this phenomenon? The patents are on the books, and it's been going on for many years. Look up.

[I've removed that link as discussions about chemtrails don't fit on this blog, N.]

Steve Bloom

Uh-oh.

Steve Bloom

Lodger, Emanuel and co-authors have proposed much-enhanced TC activity as one mechanism for the extreme mid-Piacenzian Arctic temps, but remember that minimum SSTs around 26C are necessary for such storms to survive, and rather more than that if sub-surface waters are significantly cooler, plus of course atmospheric conditions have to be correct (persistent high pressure e.g. would suppress TCs). Their results show the storms all dying by the time they reach the sub-Arctic, although cold-core successor storms will advect plenty of heat on into the Arctic Basin. Enough, they think.

David Goldstein

Alexander mentioned his friend not seeing how the loss of Arctic Ice could effect her children. I have made a video that addresses this to an extent. It is still a rough cut, but I would be interested in feedback. The website to which it refers is under construction. Thanks. Here is the direct link to the vid: https://vimeo.com/63017088

Artful Dodger

Villabolo wrote | April 01, 2013 at 02:37

"Arctic loses ice, we lose crops."

Hi Villabolo,

Here's a hit from the past, an oldie but a goodie. See if any of this rings true:

"As the ice pack recedes, storm tracks go farther north and midlatitude rainfall patterns shift eastward."

J. O. Fletcher (1968) "The Polar Ocean and World Climate" The RAND Corporation, Santa Monica, California.

Seems that scientists knew 45 years ago the general effects of Arctic sea ice loss: Storms move North, and drought in the Great Plains.

hmm...

Dave C

I wouldn't read too much into the arctic oscillation value. There have been two years this decade with exceptionally low winter ice gains- 2007 and 2010. In winter of 2007 the AO was unusually positive. There have been two years with unusually large winter ice gains- 2008 and this year. In winter 2008 there was a positive AO, but not as big as 2007. It seems unlikely that there is an obvious relationship between AO and ice gain/melt.

Steve Bloom

Yet another near-future Arctic feedback has been found to be much stronger than assumed in the models.

I have to say that at some point surprise becomes a difficult response to muster.

Next?

Robert Fanney

I'm still putting it at 10% chance of total melt this year. A large cracking event, though certainly impressive and ominous, does not account for the entire volume of ice out there (still rising, still looking about the same as 2012). The conditions of MYI are far worse, but there's still quite a bit to go. And weather, as always, is a huge uncertainty. In my view ENSO, SSW and AO are not predictive.

Furthermore, in context, cracking is just one factor. At this point, to say 100% loss by end of summer is an absolute certainty is just a bit ambitious. It's easy to get hypnotized staring into the eye of the snake (and it's a pretty dire one at that). But over-prediction would not help at all. In fact, it would only give fodder to deniers etc. Further, calling melt dates out to 2020 is hardly whistling in the wind. Any total melt this decade will be unprecedented. And I think the chances of that are, far, far higher.

Of course, as the season progresses we'll have more evidence. It could be that A-team is entirely correct and a Wadhams style total melt will happen this year. But even Wadhams is calling for a 2016 or 2017 final melt date.

This assessment isn't hope. Nor is it denial. It's just not getting too focused on one set of details and losing track of context.

In any case, we're all here watching the Arctic like hawks. So any changes will be completely visible for us to see. As I said before, we'll have a better idea if total melt conditions are really 40-50 days ahead as we get closer to May.

Robert Fanney

... and one more point.

I want to see what fresh water melt from Greenland does as a feedback. More on this later.

Chris Reynolds

Nightvid Cole,

The winter volume gain in the Siberian sector accounted for more than half the winter loss in the American.
http://dosbat.blogspot.co.uk/2013/03/what-caused-volume-loss-in-2010-part-2.html

Robert Fanney,

The stopping blogging thing was a rhetorical device to underline my confidence.

As an aggressive prognostication I think Wadhams is probably giving the most pessimistic outlook that's physically tenable. In September 2012 Wadhams said:

"This collapse, I predicted would occur in 2015-16 at which time the summer Arctic (August to September) would become ice-free. The final collapse towards that state is now happening and will probably be complete by those dates".
http://www.guardian.co.uk/environment/2012/sep/17/arctic-collapse-sea-ice

This makes that time period the earliest I think a total collapse is possible.

****

To get back on topic, although I do welcome a further discussion of what this year will bring...

The coldest March for over 50 years is spilling over into a wintry start to April and the latest long-term charts bring little cheer.... ...I was struck, therefore, by the forthright views of a Peak District farmer I spoke to this week. He was adamant that the climate has changed in recent years and said that spells of wet and dry, cold and warm are more prolonged now. His belief is that we get stuck in ruts of weather nowadays and we lurch from one to another, impacting directly on farmers' livelihoods. The last year is testament to his views and the science backs him up. Be it through global warming, melting ice sheets or changes in the oceans and the jet stream, there is a strong signal that the climate is indeed turning more extreme. So while this April will eventually warm up and spring will emerge in earnest, it seems only a matter of time before we lurch into yet another spell of severe weather.

That quote is from John Hammond, a BBC Weather presenter with a Masters in Meteorology, who's a former Met Office meteorologist.
http://www.bbc.co.uk/weather/features/21977085
People are starting to wake up to what's going on.

Hans Verbeek

R. Gates: thank you for your comment.
But we still don't know what causes SSW's and what we can expect for the future.

VaughnA

Currently on the West Coast of North America we are having a "Summer in March" event. Temperatures have been 22C to 26C for the past 2 days with abundant sunshine. The forecast is highs in the 20C to 22C for the next several days. Average high temperature for the first of April is around 14C to 17C according to the Weather Underground for my area. With one minor exception the weather this winter has fluctuated between warm and wet and trending warmer and drier as winter turned to spring. Just saying it is not cold everywhere. From the looks of things some of this warmer air has moved close to the Arctic Ocean. This warmth will at least affect the peripheral Arctic regions as it pushes northward.

Steve Bloom

Northwest coast, Vaughan. It's pretty close to normal in California.

Steve Bloom

Hans, my guess is that SSWs will increase as expansion of the tropics proceeds with warming, putting more warm air in the right place more frequently. But have you looked at the research results on this question and in particular the model results?

Neven
But we still don't know what causes SSW's and what we can expect for the future.

However, we do know that it doesn't make for a good start to the 2013 melting season. :-)

SATire

Kevin,

"In the grand scheme of things it matters not whether the sea ice extent falls below 1M km^2 this year, next year, or in 2020. It will - this decade or next - and then maybe, *maybe,* ..."
I would agree to you and many others posting here: It will happen soon; the exact year it happens doesn't matter. E.g. 10% probability this year, 50% until 2017, 90% probability that it happens once until 2020 - that is concrete enough to change modelers view on their business.

"...there will be enough political will to try and right the ship as best we can."
Politicans will do nothing poeple don't like. So we would need poeples will to change politicans mind. In some parts of Europe and Asia that is feasible - in Americas I suspect poeple prefer staying consumptive and trying to deny for that purpose. I would be very happy if you could proof me wrong here.

Building the dyke 1 m higher is not a big deal of course. Changing weather patterns could be - we do not know yet. Maybe we have to say good bye to the westerlies and mild winters and we expect more rain and warmer summer-autumn. We will have to accept that if we do not want to start WW3 against over-consumptive poeple...

To come to my point: It is interesting to watch the arctic, learn a lot here and it is good to get an idea about our future. But a big melt will not keep poeple from consuming. Maybe you will get an "oops" every summer and then poeple again buy their oil for winter and private mobility.

Hans Verbeek

@Steve Bloom: thanks for the nudge in the right direction.
More about SSW's:
http://www.sciencedaily.com/releases/2011/01/110121081051.htm
and
http://gmao.gsfc.nasa.gov/researchhighlights/SSW/

wayne

SSW's my be a symptom from a larger collaboration of events, either from the Mesophere or from the sea ice all at once, olar Stratospheric Vortex can be made unstable and prone to collapse. I just worked out some results from a search as to where the heat from vast areas of thinner sea ice has went. The results surprise at least tentatively.
http://eh2r.blogspot.ca/

"The coldest March for over 50 years is spilling over into a wintry start to April and the latest long-term charts bring little cheer."

weird when the Canadian Arctic is opposite vastly warmer.

A-Team

The imagery series below shows the melt situation in the southern Beaufort at the end of March 2013. The reddish brown region corresponds to an early melt stage -- the yellow shows where else besides the Beaufort this condition occurs, notably at the Nares Strait ice arch.

We do not having matching sensor imagery for 2012 but in Modis visible, this corresponds to mid-May in the previous year, itself a record melt year.

 photo BeaufortMelt4_zps41f97e4a.jpg

Neven

I shopped around a bit and here's what I found:

- MODIS black hole is gone
- Big dipole anomaly continues
- A large patch of open water behind Franz Josef Land
- Big cyclone forecast to move over GB next week

A-Team

This blog is not about sea ice. It is about heat gain during the insolation period and where we sit between the best case scenario (dry snow on ice, 75% reflected) and worst case scenario (open water, 0.06%).

That's an integral over the season; it was already a bad number in 2012 and it will be far worse in 2013.

I am just baffled by people grasping at straws (a million sq km, melt pond ice). That 7% residual slush (or even twice that) is largely irrelevant to this integral.

We have already approached a decent approximation of the worse case scenario. The planetary heat budget is already significantly affected by the ice loss to date.

When Tinker Bell intercepted the poisoned draught intended for Peter and drained it to the dregs, we all clapped our hands and were able to turn the situation around. That's not going to happen with sea ice.

 photo tinkerBell_zps80e58064.jpg

SATire

A-Team,

"This blog is not about sea ice." Nice to read, that you are innovating new business models for this blog for the time when arctis becomes ice-free all year ;-)

"It is about heat gain during the insolation period"
One comment to that: Once arctis becomes ice-free in winter, it will cool the oceans much more than today: Evaporation cooling is way more efficient than radiative cooling. The later will nearly stop anyway once the atmosphere is warm and humid there. Evaporation will suck the Atlantic water north and cover the continents with a ton of wet snow. The persistent depression over the artic ocean will kill the jet stream and the westerlies - leaving only the Antarctis to cool the Equator.
What would that mean for monsuns, westerly, northern trade wind, ... Persistent winter weirdness globaly, until we will get used to that new world?

A-Team

I can only take cold comfort in that -- even with summer ice completely gone, we will still have to wade through decades of winter re-freeze.

That combination is the worst of both worlds. Maximal heat gain in summer, maximal heat retention in winter.

The surface temperature of the ice on the Beaufort on today 01 Apr 13 ranges from -14.9ºC to -35.9ºC (taken off the infrared scale on the image above). It was way colder during the winter.

SATire

"Maximal heat gain in summer, maximal heat retention in winter." How can such a scenario not lead to more and more ice-free month in the dark season? And to the subsequent global winter weirdness?
Wipneus exponentials point to 2020 for 6 ice-free month/year. I would guess from that picture 1 decade more for the other 6 month (of course ignoring bays and shallow shelves).

Anyway - no reason in sight to take comfort.

Chris Reynolds

A-Team,

"The planetary heat budget is already significantly affected by the ice loss to date."

That's an interesting point, I'm not sure I agree on it. Much of the energy gained in the summer, by ocean warming and the latent heat involved in the enthalpy of fusion of ice is emitted into the atmosphere during the autumn then to be radiated to space. So the ice ice / ocean system is acting like a massive capacitor, storing energy and releasing it. Then of course there's heat emission in winter due to thinner ice, more heat leaking from the summer energy stored in the capacitor. That volume keeps going down tell us that despite these energy losses there is a net gain in ice/ocean system energy over the passing years.

The problem now is that this cycle is out of step with the cycle as it used to be, where thicker stronger Arctic sea ice kept the heat flux over autumn/winter down, and restricted energy storage in the summer.

So on a yearly basis I don't think the planetary energy budget is being screwed up as much as the major issue in that respect: CO2 emissions. To me the atmosphere is the place of the major systematic imbalance.

SATire,

At some stage a combination of CO2 levels and low cloud created by the open ocean could keep the ocean from freezing, and this might not take until the latter part of this century.

The changes in the atmosphere are just the start. It will intensify until we have new seasons; here in the UK it looks like colder winters and wetter summers - for the medium term at least.


Chris Reynolds

SATire,

Just read your last comment, so in addition. With 6 months ice free (not sure I believe the 2020 date - anyone have a graph?) enough energy will be gained to severely retard ice growth over the winter. I suspect that with such a situation a perennially ice free state will follow in a very short period.

Jim Hunt

Does anyone fancy a little festive fun, lovingly prepared by yours truly, especially for All Fools' Day?

http://econnexus.org/the-economist-being-economical-with-the-truth-about-climate-change/

R. Gates

Regarding the notion that we don't know what causes SSW's - We actually do know what causes them, but we don' have all the details about the exact dynamics behind those causes - though I think we are getting very close. The energy of SSW's definitely do start at lower latitudes down in the troposphere as vertically directed Rossby-like waves. Many SSW's (even perhaps all whose precursors are accessible to reanalysis data since the 1950's) have precursors that begin in south central Asia and can be seen as waves of warm air that travel at 10 hPa and higher from south to north. Once reaching the pole, this warm air descends, increases pressure, warms even more, disrupts the vortex, and all sorts of other interesting effects. Here is a very revealing chart that shows the progression of this latest SSW that took place in Jan. 2013:

http://tinypic.com/r/4k6v4i/6

The SSW actually hit over the Arctic pole around January 6 or so, but if you look at this chart, which shows the temperature anomaly at 10 hPa, you'll see that it begins around Dec. 15-20 down around 15 degrees north in Asia. This chart covers the regions from about 70E to 120E, right over Asia (i.e. if you ran this same reanalysis over any other part of the NH, you would not get anything that so clearly shows this pulse - it definitely came from the Asian continent.)

You can clearly see the pulse of warm air traveling to the north between mid-December and the SSW event in early January. In doing reanalysis of SSW events going back to the early 1950's, this kind of pulse is very typical. There is much more I can add to this and if Neven would like, I'd be glad to do a guest post on SSW's (not too technical), with lots of charts that show even more interesting details which would reject that notion that we don't know what causes SSW's. BTW, much of this is my own personal and collaborative private research and not yet widely distributed.

A-Team

Peter Wadhams ... from extensive internet browsing, I had formed the early impression of a discredited, attention-seeking academic (likely half-senile), with a message of alarmism covertly linked to peddling some economically self-serving remedy, in the consensus view of reputable climate modelling scientists, not so different from the nutter two bar stools over muttering on to no one in particular.

So you can imagine my surprise upon learning of a 1974 Ph.D in mathematical physics ("The effect of a sea ice cover on ocean surface waves"), a 1994 ScD for published work, 30 seasons of field campaigns in the Arctic, a full professorship at Cambridge University (one of their better schools), numerous and continuing peer-reviewed articles in the better scientific journals, and many thousands of subsequent citations by other scientists in still other journals.

I know first-hand what this entails -- 40,000 hours of hard labor. What then makes folks, who themselves are yet to place 10 bricks in a wall, think they are so well-positioned to dismiss Wadhams' predictions?

If he's right, that's a colossal embarrassment to the climate modellers so trash-talk from that quarter is understandable.

Shooting the messenger has a long history of not accomplishing much, not just the Egyptian lady enraged at a messinger (Henry IV, 1598) but back to Antigone and Plutarch.

So let's not be King Canutes and think 'later-this-decade' Delayism is going to hold back the tide. To defend that position, you'll need better qualifications than Wadhams.

 photo canute_zpsb60d3476.jpg

VaughnA

Steve, Western Washington State about 45.8 degrees north and 122.7 west in between the storminess in the Pacific and the cold weather farther east. My point is that it is far from cold in mid latitudes everywhere.

Steve Bloom

Sure, Vaughan, but also don't forget that spring and fall are poor times of year to look for temperature extremes, plus of course the NA West Coast is rather famous for having moderated weather most of the time. One can have an extreme anomaly (although I suspect your present weather falls short of that), as most of the U.S. did last year with a May-like March, but it won't be perceived as extreme because it's not in an absolute sense.

SATire

Chris,

"At some stage a combination of CO2 levels and low cloud created by the open ocean could keep the ocean from freezing, and this might not take until the latter part of this century." You don't think, that 400 ppm CO2 would do that? At least there is some risk for that, it is in the uncertainties of Miocene, isn't it? Maybe it only takes some more years of heat accumulation at current forcing to get us there.

Steve Bloom

The Canute canard strikes again! :)

As many will know, Canute in fact was proving to his suck-up courtiers, who apparently had gotten rather carried away with praising him, that any attempt to command the tides to change their behavior would be useless.

Great graphic once again. Am I detecting a theme? :)

OldLeatherneck

Lee Grenci, at the Weather Underground has written several articles about Radiational Cooling and at least one on SSW events in the past several months.

SSW Post:
http://www.wunderground.com/blog/24hourprof/comment.html?entrynum=16#commenttop

Radiational Cooling Posts:(Most Recent 1st)
http://www.wunderground.com/blog/24hourprof/archive.html?year=2013&month=03
http://www.wunderground.com/blog/24hourprof/comment.html?entrynum=14#commenttop
http://www.wunderground.com/blog/24hourprof/comment.html?entrynum=1#commenttop

While much of this information may be common knowledge to many posters here, for the "Meteorologically Challenged" such as myself, these posts seem very relevant to much of what is currently being discussed here.

OldLeatherneck

Neven,

My most recent post may have gotten trapped in the "Spam" locker.

R. Gates

In following Dr. Wadham's work for quite some time, I suspect he'll (unfortunately) be proven as the most accurate in terms of forecasting the arrival of a virtual ice-free summer Arctic. It is quite remarkable to think that just a few years ago the average date was in the 2100 range. To think that 2016-2020 is now quite reasonable shows how far away from the true dynamics the models have been. Once more, I think the full accounting of the influx and advection of heat from the warming oceans and that effect on the melting and reduction of sea ice volume from underneath is a big part of the failure of the models.

Chris Reynolds

SATire,

It is within the range for the Miocene, it's also within Abbot & Tzipperman's range.

A Team,

Wadhams has had enough standing here in the UK to have an open invitation from the Royal Navy to go on their submarine missions under the Arctic sea ice. I've read this was at the behest of Margaret Thatcher, but that maybe here-say.

Nightvid Cole

R. Gates,

Have you not read the P. Rampal et al. paper "IPCC climate models do not capture Arctic sea ice drift
acceleration : Consequences in terms of projected sea ice thinning and decline " ?

I think it is the increased drift speeds of ice as it thins that accounts for the vast majority of model failure, not an increase in ocean heat advection from lower latitudes.

The rest of the discrepancy can be (maybe?) accounted for by the snow albedo feedback, given that the models also seriously underestimate NH snow cover retreat in May and June. (or even multiyearice-albedo feedback???)

Shared Humanity

....most people will be able to make light of even sharp changes in the Arctic unless there are clear, immediate implications that will impact them.

I live in Chicago and I can state without reservation that most intelligent people I talk to consider the loss of sea ice in the Arctic a curiosity. They'll talk to friends and relatives over a beer at a backyard cookout but it simply does not register as a serious threat. Most of the U.S. is in this space. It will take dramatic, devastating impacts before the U.S. wakes up. The droughts of the past 3 years has not done it.

Shared Humanity

So the ice ice / ocean system is acting like a massive capacitor, storing energy and releasing it.

I really like this analogy. If the sea ice/ ocean transfers are acting like a capacitor, the deep ocean is acting like an immense battery.

Neven

Two comments from Oldleatherneck and Chris Reynolds released.

if Neven would like, I'd be glad to do a guest post on SSW's (not too technical)

Anytime, R. Gates! It'd be an honour. But only if you feel like it and have the time.

Chris Reynolds

Nightvid Cole,

There are more reasons for models not representing well. For a start many models have too strong a temperature inversion in the Arctic winter, this will lead to a stronger thickness/growth feedback, meaning not only does is thicken thermodynamically more than in reality, but in response to low sea ice episodes the models concerned will grow more ice the following autumn. Thus they have a greater negative feedback countering ice loss than seems to be the case in reality.

Shared Humanity.

The ocean introduces another complexity. Most of the warm Atlantic Water is decoupled from interaction with the ice because it's about 200m below the surface. But it will interact weakly through heat fluxes and mixing events. If it's a battery it's connected via a high value resistor.

OldLeatherneck

Quoting Shared Humanity:

I live in Chicago and I can state without reservation that most intelligent people I talk to consider the loss of sea ice in the Arctic a curiosity. They'll talk to friends and relatives over a beer at a backyard cookout but it simply does not register as a serious threat. Most of the U.S. is in this space. It will take dramatic, devastating impacts before the U.S. wakes up. The droughts of the past 3 years has not done it.

It's even worse in my part of Texas where 80% of the population gets their news from FOX NEWS! Ironically, it is the grain producing region from Texas north to the Dakotas that will be suffering the most from drought and groundwater depletion. Yet, it is their elected officials that proudly claim that AGW/CC is socialist plot to destroy capitalism.

Somehow, we need to proclaim very loudly:

"What Happens in the Arctic,
........Doesn't Stay in the Arctic!!"
SATire

Sorry Chris - missed your post "With 6 months ice free (not sure I believe the 2020 date - anyone have a graph?) "

Wipneus Arctische Pinguin shows that in top right graph: https://sites.google.com/site/arctischepinguin/home/piomas

Robert Fanney

@ A-Team

My personal opinion is that Wadhams will come much closest to the mark than the models. He seems an interesting fellow and being stuck on navy subs for a long time can make anyone seem a little nutters.

@ Chris Reynolds

No way all that extra heat going in during summer is being re-radiated during winter. That ocean is definitely taking up some of the extra heat. The land and ice sheets will take up some too. We see that already in permafrost state change. GHG will trap more and more of it and transfer to the rest of the atmosphere as positive deta F increases along with CO2 + methane.

Robert Fanney

... much closer....

Bah. Please excuse typos...

Steve Bloom

See here for how CBD used A-Team's Caravaggio take. All very amusing.

Wipneus

There is a assumption in those extrapolations of course: the processes that have led to the past decline are unchanged in the future. That assumption WILL break down once there is no more summer ice too melt, the freezing seazon will not start with ever lower amounts of ice. The sensible heat involved is much more volatile.
I expect the rates of decline to slow down well before the ice free period is 6 months.

Chris Reynolds

SATire,

Thanks for that.

Wipneus,

Not sure how it will pan out, but a change in loss rate is a reasonable expectation.

Above it was stated that it's 6 months ice free by 2020. Actually it's month 6 (June) going to zero on trend extrapolation by shortly after 2020.

From my reading of that graph it seems to be the post May months that dip down out of step with the other months, in part this seems to be due to the spring melt years of 2010 - 2012. Again I'm drawn back to wondering how much thinning in the spring will set the scene for an ice free state in the summer.

Robert Fanney,

I didn't say it was, I did note that the volume decline shows that the ice/ocean system is gaining energy. But if the ice/ocean system wasn't losing so much energy we wouldn't see the substantial warming of the atmosphere, happening when there's no sunlight coming in, during the autumn.

SATire

Wipneus,
"There is a assumption in those extrapolations of course: the processes that have led to the past decline are unchanged in the future.
That assumption WILL break down once there is no more summer ice too melt, the freezing seazon will not start with ever lower amounts of ice. The sensible heat involved is much more volatile.
I expect the rates of decline to slow down well before the ice free period is 6 months."
I have to admit, that I missused your graph intentional - that is not fair and I have to explain in more detail, what I thought above.
The albedo feed-back resulting in that exponential only works, if there is sun - e.g. from April to August. Maybe due to heat storage in the sea until Oktober or even November. But evaporation cooling (which is way more efficient than radiation cooling) will cool the uncovered ocean in the dark month.

But we know the stable state of clima belonging to a 400ppm CO2 from climate paleontology (Miocene). What we do not know and what is the reason for our discussions are the way to the stable clima and the time scale.

Since open sea in the arctis will kill the polar vortex, the jet stream and hence the atmospheric flux of energy to the arctis, the oceans currents must do that job on the long run.

I think, evaporation will trigger that transition. Once we got e.g. 10 °C in the upper 10 m in the Amundsen Basin, the game would change: 10 K x 10 m gives enough energy to evaporate 0.1 m (~3,000 kJ!) of water. Loss of 0.1 m of water would increase salinity in that upper 10 m by 1% (~10PSU) or 1 PSU for the 100 m and destroy the halocline there. So convection will start in the Amundsen Basin and the ocean will stay ice-free in winter. Of course bays and shallow selfes will freeze, but the open sea in the basin will change the wether weirdly enough for us.
In the Canada Basin it will take much longer due to a delta of 0.4% salt and 200 m layer thickness - but that is just a matter of time for mixing.

Ron Mignery

SATire

Evaporation killing the halocline is a positive feedback I have not seen discussed before. What produces the basin haloclines in the first place? Is it brine jets from sea ice formation taking salt to lower levels? I've read that these jets, if too vigorous, could actually cause mixing and disrupt the halocline rather than enhance it. Does sea ice formation in the vast areas previously covered by MYI strengthen the halocline or weaken it? Is it generally agreed that total destruction of the halocline would produce a year-round ice free Artic? Sorry to be such a pest with these elementary questions.

Kevin O'Neill

The pycnocline is essential to a winter ice cover. Ice formation would otherwise require that the entire column depth reach freezing temperatures.

Wadhams has a great explanation of ice formation at How Does Arctic Sea Ice Form and Decay?

SATire

Hi Ron,

you think that idea should be discussed somewhere else? Maybe in that Forum, because it is off-topic here? Probably you are right...
The halocline is a result of the ice-forming & -melting processes and also of inflow from Atlantic and fresh water from rivers. I think most poeple would agree that the atlantic water beneath it would kill any ice above, if the halocline would vanish.

Chris Reynolds

Horizon's Global Weirding documentary is on tonight on BBC4 at 20:00.

Not a great documentary, but in view of this thread it might be interesting for people who can get BBC4.

Glacierchange.wordpress.com

The low Barents Sea Ice cover will continue to have an impact on Novaya Zemlya glaciers such as Krivosheina where recent retreat has freed a new island.

A-Team

The Beaufort ice pack is very much on the move. The fast-moving western tip of a recognizable central feature, traced for 41 days (23 Feb 13 to 02 Apr 13), has moved 479 km or 11.7 km per day at 0.49 km per hour. The angular velocity about the feature's Euler pole at 82.5ºN 140ºW is quite rapid, about 1.2º per day.

By 02 July 13 the tip will have swung around 76.4º from its 21 Feb 13 position putting it approximately at the Wrangel Island meridian. This will put a sizeable percentage of western multi-year ice coming along for the ride in the center of the melt zone in the center of the melt season.

 photo BeaufortMoveAprilB1_zps605e543b.gif

A-Team

Here is what the lower Beaufort Sea -- our year-on-year melt timer -- looked like on 01 Apr 03. Note the parallel zones of melt stages above Banks Island.

This is not a tinted grayscale but an authentic RGB made from the three infrared wavelengths measured by the AVHRR satellite. It combines the information in the 3 grayscales in a way that the human eye cannot -- here, the whole is more than the sum of its parts.

To make the image, individual channels are first 'equalized' to make proportionate use of color space, inverted to brighten cracks, then composed into the final., and optimized slightly in overexposed areas.

This type of image cannot be made until spring because all but channel 4 are ruined by oblique sun angle and winter darkness. Comparable satellite data for 2012 and earlier years has apparently been discarded by Environment Canada.

926 pixels wide:
 photo Beaufort234_zps510631e1.jpg

A-Team

At last! I've found the source of my confusion about this spring's melt season being 40-50 days ahead of record year 2012.

We know from the mathematical certainty of Recursion to the Mean that a good melt year must follow the bad.

Turns out all I needed to do was update my calendar. March and April can be fused into Mapril. And June is a pleasant month, so why not repeat the early days there.

The net effect is the 2013 anomaly goes away!

 photo revisedCalendar2_zpsf62f16a6.png

John Cartmill

I've been watching western Greenland MODIS and it seems to be using your Mapril calendar as well.
Matt Owens has a nice post at Fairfax Climate Watch about the status of Greenland snow cover.

http://climatewatch.typepad.com/blog/2013/04/greenland-snow-cover-all-wet-in-december.html

SATire

A-Team,
nice to read the obvious. Just one day late with that.

AmbiValent

At first glance, the area and extent numbers don't look bad. Unfortunately, all the other news and images more than makes up for that. And it's only the beginning of melt season...

o/~ My feelings can't reach you, Our bonds being torn apart
The clouds drift away regardlessly on a
Grey Wednesday

Now, remember the spectacular past
When everything was bright, when you fell in love

Now, remember the time we loved each other
When we stared into each other's eyes

Now, remember the spectacular past
When you lived for a dream, when you loved each other o/~

A-Team

I built a couple of imagery interferometers for the purposes of detecting slight daily ice pack motion and the extent to which multi-year ice is part of that motion.

The ice in the Beaufort is moving rapidly enough that the motion is easily detected between avhrr photos taken two hours apart, in particular between beaufort.130402.0315.4 and beaufort.130402.0133.4.

However wider time differences are needed to measure the direction, velocity, rotation, and acceleration with any accuracy, beaufort.130402.2020.4 is used below.

These are all NOAA-16; there would be registration jitters if NOAA-15 and NOAA-19 satellite products are mixed in. The observed daily motion is completely consistent with that seen in the 41-day product above.

The entire field of ice in 'Beaufort' imagery is moving coherently up towards the Chukchi. A substantial part of this ice is thick multi-year as you can see from overlaying on the 'anatomically correct' ice pack radar animation above.

925 pixels wide:
 photo interferometric_zps94e039e5.jpg

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