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viddaloo

«and with just a month or two to go before the melting season gets going»

Bah, Neven. Not even you are thick, aka 'conservative', enough to believe the freezing season will go on for two more months until April 19th. Is this some sort of competition to look like a dork? In that case, what is the prize?

Neven

A month or two means between one and two months, so, somewhere between March 19th and April 19th, you know, give or take. Area and extent are basically flatlining during March, and volume continues to increase until the max in April. So yeah, in a month or two the melting season gets going (relatively slowly until (the end of) May).

Why am I even defending myself?

Is this some sort of competition to look like a dork?

Well, if it is, you win. :-P

And the prize is a ban if you hijack this comment section.

viddaloo

So basically you're saying the 2016 melt will start in June. Amazing.

AbbottisGone

I think the orbits are decaying...

StuDownUnder

Hi there Neven (and all). I've Been lurking here for years (a lot of years) and have loved all the fantastic analysis here.
I wanted my first post to be some sort of clever sharing of data/observations in the spirit of this place, alas, if I wait for that I may never post!
Just a comment on the above comments by Viddaloo.
*my interpretation* of what Neven said was that, the Arctic melt season will start around the third week of April (as per usual), proceed slowly at first, until the end of May when it then speeds up. Also, that we may or may not see a new minimum max extent before end of April (depending on the usual set of things that have been discussed here extensively over the years).

Looked like a perfectly reasonable statement to me.
Hope this clears it up for you Viddaloo?

wayne

Tie my kangaroo down not sot so fast StuDownUnder,

This time is more complex by so much snow there is on sea ice. There is 2 things ongoing at once, less sea ice accretion for sure, but the possibility of more apparent sea ice by drifting snow over open sea water colder than 0 degrees C, which helps the formation of sea ice and also fooling of sensors which may show that there is more sea ice, while there is in fact floating snow!

The maxima has nearly 0 chance of being late, every chance of being earlier than last year, extra snow on sea ice makes the overall sea/snow ice temperature significantly warmer than the air right above. This is what I am thinking about. It is not at all like last year which had comparatively very little snow.


Kris

And again a downtick at ADS - Japan, this time -64608 km2, thus over a century in two days. If it would continue like that, the max extennt for 2016 already could have been reached ... oh boy, it's as bad as it looks like....

Neven

Indeed, Kris. Last year's JAXA max was reached around this time, and started with a 2-day drop of 172K, which was almost bettered at the end of the month. Almost.

If in the next week JAXA SIE manages to add another 100K to the current difference of -119K with the preliminary peak reached two days ago, there's a good chance of a new record max.

As I write in the blog post, CT SIA is even more spectacular with the current preliminary peak being 460K (!) below the 2011 record max. But I'm expecting there will be a second peak there. There has to be one, right?

viddaloo

I'm confident the extent max will happen in February this year, but than the volume max may linger until April. But does this mean the melting season does not begin before April? Semantics, of course, yet if you think about your favourite mountain area, I'd say spring melt begins when the low–lying areas lose their snow cover, even though the glaciers and fields up high may still gain some more snow mass.

StuDownUnder

Wayne, slight misunderstanding, I wasn't making my own prediction, just (foolishly?) getting involved in the conversation between Neven and Viddaloo to clarify Neven's comment On the start of the melt season. Certainly wasn't commenting on the likelihood of record for winter extent.
However...as alluded to by you and others including Neven, (and my own observations, dimmed somewhat by the vast distance between me and the arctic, and all the roos hopping around in front of my telescope) it sure looks like a record is on the cards.
PS- (OT)in dry summers we often get lots of kangaroos mowing our front lawn.

Jim Hunt

We certainly live in interesting times Neven!

If I may add some extra information to the mix, from ice mass balance buoy 2015F:

http://GreatWhiteCon.info/resources/ice-mass-balance-buoys/winter-2015-16-imbs/#2015F-Map

The buoy currently reports:

Pos: 81.72 N, 159.67 W
Air Temp: -25.86 C
Air Pres: 1015.65 mb
Snow depth : 17 cm
Ice thickness : 163 cm
Freezing Degree Days: 3178

Would you like to play "spot the difference" with other similar buoys in the same general area on the same date last year?

http://GreatWhiteCon.info/resources/ice-mass-balance-buoys/winter-201415-imbs/

Benjaminwinchester

I'm not sure I see the significance of earlier sea ice extent maximums. Okay, so the melt season will be longer - sort of - but does this really affect the ice extent? How much can it?

If the sea ice extent is flat for a long while (as is typical in March and April), it's relatively easy for minor fluctuations to change the date of the maximum. A minor fluctuation up in February - whoops, there's the max for the year.

So that's why I'm not that concerned with the date of the maximum. Is there something I'm missing?

But as for what the maximum is... that seems pretty obviously significant, as a rough thermometer for the region. And that's probably even more significant if you look at a running average. (maybe 30 days?)

Colorado Bob

Chris Mooney has a rather interesting quote from Dr. Francis :

Scientists are floored by what’s happening in the Arctic right now

“We’ve got this huge El Niño out there, we have the warm blob in the northeast Pacific, the cool blob in the Atlantic, and this ridiculously warm Arctic,” says Jennifer Francis, a climate researcher at Rutgers University who focuses on the Arctic and has argued that Arctic changes are changing mid-latitude weather by causing wobbles in the jet stream. “All these things happening at the same time that have never happened before.” ............“I think this winter is going to get studied like crazy, for quite a while,” says Francis. “It’s a very interesting time.”
https://www.washingtonpost.com/news/energy-environment/wp/2016/02/18/scientists-are-floored-by-whats-happening-in-the-arctic-right-now/

Neven

I read that article on the WP yesterday, and decided I would use that last quote by Francis to preface my upcoming Winter Analysis. Let me be the first to study this winter like crazy. ;-)

So that's why I'm not that concerned with the date of the maximum. Is there something I'm missing?

No, you're not, Benjamin. The date of the max is only interesting statistically speaking, like: Is the max occurring earlier in the long term?

And like I wrote, even the max itself doesn't necessarily mean that the melting season will be this or that. But of course, there are exceptions. And sometimes there are exceptional exceptions. ;-)

Pertti Kellomäki

I'm curious: is there much correlation between the max date/extent and the subsequent minimum? It is pretty clear that any given year can go in wildly different directions, but common sense would suggest that there should be at least some correlation.

viddaloo

Pertti, once you've entered the spring Plateau (see http://i.imgur.com/7M00nUj.png ), there are 3 significant candidates for a correlation with the autumn minimum: 1) The level of the Plateau, ie how low the maximum extent is, 2) the start date of the Plateau, and 3) the length of the Plateau.

To me, however, this 2016 graph (the raw graph without the Plateau drawn in) looks a lot like the 2007 exceptional year, with then record low max record early. A significant step change like 2007 made this hat–trick: A) Record early Plateau entry, B) Record low maximum & C) Record low minimum — all of them at the time, as they've since been beaten by other years.

D

FishOutofWater here. The crash in sea ice area and extent is affecting the northern hemisphere's atmospheric circulation.

You might want to check out my post today at DKos.

http://www.dailykos.com/stories/2016/2/19/1487234/-Arctic-Heat-Sea-Ice-Collapse-Has-Split-the-Polar-Vortex-in-Two-Sending-El-Ni-o-Rains-to-Alaska

StuDownUnder

As well as the large, stubborn anomalously warm area between Siberia and the pole, according to the latest forecast on reanalyser, http://cci-reanalyzer.org/Forecasts/
There looks to be a large area of anomalously warm air heading into Baffin Bay from 21st onwards.

StuDownUnder

Oh forgot to add, thanks fishoutofwater for that link-an excellent read!
The sort of science that the head of our (Australia) premier scientific research body (CSIRO) has decided, in his infinite wisdom, to abandon! Sigh.

Bill Fothergill

@ Benjamin & Pertti

As regards correlation between the March (or February?) annual maximum for Arctic Sea Ice Extent and the subsequent September minimum, you could look at the trend lines generated automatically by NSIDC on their Browse Image Spreadsheet (or Subset) Tool.
https://nsidc.org/data/bist/bist.pl?config=seaice_extent_trends

(NB If you set the number of rows to 12, it will automatically give you a chart for each month.)

Personally I think the daily max is far too variable to have any predictive skill, and, in the long term at least, there appears a reasonable correlation between the March max and the September min.

However, this obviously does not predict statistical outliers such as 1996, 2007 or 2012. Additionally, the correlation breaks down spectacularly when one considers periods much shorter than, say, 10-15 years. A few years back, I looked at the correlation between various average monthly values and the ensuing September average over a period of, I think, 7 years or so. The correlation breakdown for the winter and spring months was so extreme, that the CORREL function was actually spewing out NEGATIVE correlations.

It should be obvious, that these results were utterly spurious, and were merely an artefact caused by using too short a data subset.

As alluded to in the articles posted by Bob and the Fish, the past is becoming even less of a key to the future - at least in terms of short-term predictability. For example, if we see a record (or near record) low maximum for Arctic Sea Ice, that means that there is a large chunk of open water that wasn't there before.

This open water means that we now have some feedbacks operating that work in opposite directions. The temperature over open water is largely locked by the huge thermal capacity of the underlying ocean. Therefore, this acts as a positive feedback into the energy (and hence temperature) of the overlying atmosphere. When the sun puts in an appearance, we also have the ice/albedo feedback kicking in earlier than it otherwise would.

However, at a Earth System (i.e. planetary) level, open sea in the Arctic winter provides a pathway for enhanced energy loss back to space. (Think of the Stefan Boltzmann relationship.) This should be a lesser player than the previously mentioned feedbacks, but it all goes to make it bloody hard to predict what's going to happen next.


@ viddaloo " ... 2007 made this hat–trick: A) Record early Plateau entry, B) Record low maximum & C) Record low minimum ... "

If you look at, say, the Jaxa or NSIDC data for 2006, I think you'll find that the SIE maximum was less than that seen in 2007.

Jim Hunt

A BBC video in which weatherman John Hammond briefly explains ice-albedo feedback and interviews Gavin Schmidt about the "Warmest January ever":

http://www.bbc.co.uk/weather/features/35616676

Lawrence Coleman

Interesting comments! there might be more ice forming from snowfall now but the quality will be poor due to the high relative temp of the region and the fact that the ice has been fractured heavily during the last few months. Thus volume will probably creep a little higher until maybe mid to late march and then when melt season begins will rapidly disappear and free fall until probably a record low volume/area/extent in summer.

viddaloo

@ Bill: Cool, thanks! I stand corrected. 2006 had a lower max than 2007, it just wasn't part of the ('longest plateaus') plot.

2000s plot: http://i.imgur.com/afJNFes.png
2010s plot: http://i.imgur.com/D3K7UpB.png

Colorado Bob

We all know we're poking at the dragon, but sometimes we fail to grasp just how big the dragon is. This one made me gulp -

Colossal Antarctic ice-shelf collapse followed last ice age

"This continent-enveloping ice sheet extended all the way to the continental shelf, and in western Antarctica it filled the entire Ross Sea basin." ............................ In western Antarctica, the Ross Sea is characterized by a continental shelf that extends nearly 1,000 miles from the coast and is as much as 3,500 feet deep. Anderson said the geologic record shows that as recently as 18,000 years ago the entire Ross basin was filled with ice that was so thick and heavy it was grounded on the seafloor all the way to the edge of the continental shelf.

"We found that about 10,000 years ago, this thick, grounded ice sheet broke apart in dramatic fashion," Anderson said. "The evidence shows that an armada of icebergs—each at least twice as tall as the Empire State Building—was pushed out en masse. We know this because this part of the Ross Sea is about 550 meters (1,804 feet) deep, and the icebergs were so large and so tightly packed that they gouged huge furrows into the seafloor as they moved north."

Link

Colorado Bob

‘Ice age blob’ of warm ocean water discovered south of Greenland

New research published in Scientific Reports in February indicates that a warm ocean surface water prevailed during the last ice age, sandwiched between two major ice sheets just south of Greenland.

Extreme climate changes in the past Ice core records show that Greenland went through 25 extreme and abrupt climate changes during the last ice age some 20,000 to 70,000 years ago. In less than 50 years the air temperatures over Greenland could increase by 10 to 15 °C. However the warm periods were short; within a few centuries the frigid temperatures of the ice age returned. That kind of climate change would have been catastrophic for us today.

https://www.sciencedaily.com/releases/2016/02/160219134816.htm

Bill Fothergill

@ viddaloo

My direct brain >> computer link is still non functional, and I am forced to employ my fingers in an intermediary role. This is not a particularly reliable situation, and words sometimes get entirely omitted. In this instance, my closing sentence should have had the adjectival modifier "slightly" immediately in front of the word "less", as in ...
" ...the [2006] SIE maximum was slightly less than that seen in 2007."

++++++++++

Whilst on the subject of exceptional years, it may be educational to reflect on the varied trajectories - in terms of monthly NSIDC Arctic SIE averages - taken by some of the statistical outliers. In each case, I have initially shown how each month ranked at the time, and then its current ranking. (NB 1 = lowest)

1996
Mar(1); Apr(1); May(3); Jun(5); Jul(10); Aug;(16); Sep(18); Oct(9)

2007
Mar(2); Apr(1); May(3); Jun(3); Jul(1); Aug;(1); Sep(1); Oct(1)

2012
Mar(10); Apr(18); May(11); Jun(2); Jul(2); Aug;(1); Sep(1); Oct(2)


Current ranking positions for each of the above
1996
Mar(10); Apr(8); May(11); Jun(23); Jul(29); Aug;(35); Sep(37); Oct(28)

2007
Mar(4); Apr(1); May(6); Jun(10); Jul(3); Aug;(2); Sep(2); Oct(1)

2012
Mar(13); Apr(21); May(14); Jun(2); Jul(2); Aug;(1); Sep(1); Oct(2)


Hopefully, the above might serve to demonstrate the extreme difficulty in "predicting" the September average from spring months.

During 1996, the first four months all came in at, what was at the time, record low levels. Despite this head start, the September average nevertheless contrived to be then, as now, the highest seen in the NSIDC dataset. Intriguingly, by November that year, the monthly average was again at the lowest level that had been seen, and remained so for a further four years.

At the other extreme, 2012 started off rather inauspiciously, but the June - October monthly figures still have not changed over the last 3 years - namely 2,2,1,1,2

However, 2007 managed to offer us yet another extreme type, with all 12 months initially ranked in the lowest 3. The April and October values for 2007 have yet to be beaten.

Bill Fothergill

@ Bob

I rather think that the "iceberg armadas" from Antarctica have direct parallels with the northern hemisphere Heinrich Events.

Similarly, the multiple temperature oscillations seen in Arctic records are, I believe, referred to as Dansgaard–Oeschger events.

wayne

Lawrence,

I think that snow can float in -2 C sea water forever when sunny until surface temperatures exceed 0 degrees. However, with air temperatures well below zero, snow precedes the formation of very thin ice, not so when the sun is at elevations as low as about 10 degrees (or lower), there is no reason for it to melt, its white and dark sea warms up very slowly, incrementally.
There is also night time day time balancing act, when ice forms at night then melts during the progressively longer days. But it is very correct to estimate that a relatively fresh snow/ice layer will melt far quicker than much thicker sea ice next to it, so look for a sudden crash of sea ice extent which will seem odd, that should be this exotic crio layer melting rapidly.

The max matters if analyzed holistically , and then again is one of many Arctic metrics to consider. Until the Earth warms much further, the biggest factor, amongst many, for sea ice is dynamical weather . I already consider that there was open water at the Pole during recent summers, even though it did not exactly happen visually, it is a matter of the right compaction and Arctic dipole activity, clear air , lesser Cyclones but Highs over the summer Arctic Ocean Gyre. We really haven't presented an accurate way to depict the progression of the yearly melt because extent maps are the result of morphing of the winds and the presence or absence of clouds. When it will the Poles turn to have open water, other Arctic Ocean locations may still have plenty of ice.

A better way to present the melting would be to make a map with all the leads, all open water eliminated artificially, even below 15 % extent, creating a true compacted sea ice presence in the zones where sea ice remains. This would give a better cerebral image. And sea ice would appear to vanish a whole lot more year by year, than with current data graphs, I am quite sure.

Veli Kallio

I would like to thank Bill Fothergill for his excellent comment of tabling monthly averages for each month and comparing these to the end of season melting (ice minimum).

1996: Mar(1); Apr(1); May(3); Jun(5); Jul(10); Aug;(16); Sep(18); Oct(9)

In particular, I wish to draw attention to his remark about the 1996 situation when:

"the first four months all came in at, what was at the time, record low levels. Despite this head start, the September average nevertheless contrived to be then, as now, the highest seen in the NSIDC dataset."

What I suspect drove this in 1996 was that the extra open sea in the late winter months provided extra time for enhanced energy loss from ocean to space (the Stefan Boltzmann relationship - negative ice area feedback due to the sea water getting colder due to more open water in winter).

Why this is important? Because in 1996 the climate system was still cold enough, the shallow ocean waters north of Russia cooled extensively and excessively during the later winter months when ice was missing. During the 1996 summer then the riparian discharges of fresh water from Siberia further reduced ocean's salinity of this already cold water - thus helping to amplify sea ice formation late that season north of Russian seas in that year.

When the overall climate warming has ensued in subsequent years the above anomaly has only been further amplified:

1996 Mar(10); Apr(8); May(11); Jun(23); Jul(29); Aug;(35); Sep(37); Oct(28)

But now, the inverse proces is at work this season 2015/2016 which sees a break down of a recent series of years of constantly expanding Antarctic sea ice (2015 was max).

Despite the 2015 record sea ice area around Antarctica, the growing discharges of both meltwater and ice debris from the Antarctic ice shelves or land, the sea ice 2016 has rapidly been falling well below the average of the recent years - recently at times close to the record lows for Antarctic sea ice - quite opposite (sic) to other recent years when the reducing salinity around Antarctica has seen sea ice area growing quite considerably.

El Nino and warmer Pacific and climatic system this season (2015/2016 Austral summer - Arctic winter) is now simply too warm - warm enough - to nullify the effect of sea ice enhancing trend from the lowering ocean salinity. >> I.e. the ocean salinity isn't reduced fast enough related to the overall warming of climate this year. >> As a result the sea ice in Antarctica is now lower than normally.

I propose 2015/2016 Austral summer - Arctic winter is the new baseline with too effects:

(1) the global temperature level now exceeding the melt water / ice debris negative feedback by nullifying the effect of reduced ocean salinity for sea ice area.

(2) the fluid dynamics reaching the point where the polar vortex breaks down almost altogether or the planetary waves bring the edge of the warm southern air right to the North Pole. http://globalweatherlogistics.com/seaiceforecasting/gfs.850mb.temps.arctic.html

UK Meteorological Office used to divide its forecasting to two approaches (1) chartists using analogues of previous weather maps to questimate its lookalikes, (2) modellers using computer models to create forecasts.

Using the old "chartist" approach in meteorology, I suggest 2015/2016 season (global temperature average) represents a "tipping point" from where there is no longer effective polar vortex in Arctic and the Antarctic sea ice starts also be on retreat (after previous trend of expansion during the cooler years with melt water).

Going then back to GCMs, I suggest that present global temperature 2015/2016 cab be taken as the turning point from onwards there is neither of above two systems in place. (GCMs then providing the overlying time when this year's anomaly situation will be the yearly standard.

VP - Sea Research Society - Environmental Affairs Department & Chair - Frozen Isthmuses' Protection Campaign of the Arctic and North Atlantic Oceans

navegante

My understanding was that the slow reduction of max extent over the years shows a neat correlation with the increase of average temperatures in the NH, which were record high already in 2014 and then in 2015. January average extent shows that gradual decrease. The correlation with September extent gets diluted given the so many factors influencing melting progress.

Colorado Bob

Kevin Anderson talks about poking the dragon, and he doesn't pull any punches -
Going Beyond "Dangerous" Climate Change

1:39 hour clip

Published on Feb 9, 2016

Date: Thursday 4 February 2016
Time: 6.30-8pm
Venue: Old Theatre, Old Building

Despite high-level statements to the contrary, there is little to no chance of maintaining the global mean surface temperature increase at or below 2 degrees Celsius. Moreover, the impacts associated with 2°C have been revised upward sufficiently so that 2°C now more appropriately represents the threshold between 'dangerous' and 'extremely dangerous' climate change.

Kevin Anderson will address the endemic bias prevalent amongst many of those building emission scenarios to underplay the scale of the 2°C challenge. In several respects, the modeling community is actually self-censoring its research to conform to the dominant political and economic paradigm. However, even a slim chance of 'keeping below' a 2°C rise now demands a revolution in how we consume and produce energy. Such a rapid and deep transition will have profound implications for the framing of society, and is far removed from the rhetoric of green growth that increasingly dominates the climate change agenda.

Kevin Anderson (@KevinClimate) is Professor of Energy and Climate Change at the University of Manchester.

https://www.youtube.com/watch?v=-T22A7mvJoc

Colorado Bob

Bill Fothergill -
As for the Greenland finding , most likely .

We're seeing it play out today. That cold blob in the North Atlantic, the floods of 4 years ago :

Greenland has been a recurring source of headlines in July 2012, with the calving of a new iceberg off the Petermann Glacier and surface melting across nearly all of the Greenland Ice Sheet. Now there are new satellite images of flooding in Kangerlussuaq, a key air transportation hub.
http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=78685

The North seems to melt in pulses , as the paper points to.

The South seems to just collapse in chunks, like the Larson B .

My thinking it's so driven by the ACC , that comparing the two are like apples, and asphalt.

Given what we've seen so for, crossing the Drake Passage is going to really strange. A lot of tourists are going to be thinking of the Voyage of the James Caird.

As the great cold tries to hold on against the great heat.

Hell of a time to be alive.

Lennartvdl

Colorado Bob, thanks for the Kevin Anderson talk! Good to hear this update on his views.

Bill Fothergill

@ Colorado Bob
" ... comparing the two are like apples, and asphalt ... "

Bob, when I said ...

"I rather think that the "iceberg armadas" from Antarctica have direct parallels with the northern hemisphere Heinrich Events"

I was simply referring to the fact that the term "iceberg armadas" had already been employed a bit further north. There was no intention to suggest that the dynamic melt processes in the Arctic resemble those in the Antarctic.

The evidence for the armadas however tends to be the same - namely the presence of extensive "erratic boulder" trails on the sea bed. The only plausible explanation for these "erratic" {not erotic} trails is that the debris was rafted out to sea encased in ice, and finally deposited when the encasing ice melted.

For one thing, the Arctic lacks the humongous ice shelves that are so prevalent around Antarctica.

D

Fish here. There's no doubt that the open ocean with it's extraordinary amounts of heat compared to ice covered water will radiate more heat out to space, but:

1: The open water and the storms over it produce copious clouds which hold heat in over the areas they cover

2: Huge amounts of water vapor, a powerful greenhouse gas rise up into the Arctic troposphere. The increased water vapor of the Arctic reduces radiative heat losses over the whole Arctic.

Thus, the increase in open water on the Atlantic side of the Arctic may decrease radiative heat losses over areas where the water vapor and clouds are advected by winds.

Open ocean, in this situation, has both positive and negative feedbacks on the loss of heat to space. Detailed heat balance analysis is needed to calculate the effects of this open water on heat loss over the entire Arctic.

Veli Kallio

Bill Fothergill,

I also think the Heindric Ice Berg armadas were bipolar event.

In my view the ice-free Arctic Ocean will inevitably lead into exhaustively meltwater pond pocketed North Greenland Ice Sheet (which is lying much lower than the more dome-like southern Greenland ice sheet). In addition the spatial barrier exists here (as North Greenland ice sheet is also very wide) as water sinks into ice before reaching its edge.

It is far harder for the water to run to the edges of the ice sheet or moulins to leak melt water from beneath ice. This accummulates the heat of melt water into the ice sheet destabiling the entier ice sheet - ice shelf systems.

Instead, the water ponds will rapidly grow more numerous, the old dirt gets quickly exposed as surface melts turning ice into black ice. Both the darkening of ice and melt water ponds mop up massively more sunlight. Then there will be the flash floods and rainbow events as the moist marine air precipitates over the much cooler North Greenland ice.

I think a great damage has been made by the scienfic community ignoring the dangers of the 'accummulative impact' moulins from the 'seasonal impact' moulins that drain by end of season. The inland, 'accummulative impact' moulins cannot drain and therefore turn ice inside ice sheet into a weak and unstable honeycombed ('rotten') ice which has no internal strength to survive the weight stresses of the overlying dry and colder ice layers.

Any watery ice sheet base discharges relatively little debris to long distance except where there are dry ice preserved in base matrix to carry out moraine or erratic boulders out to the sea. Hence, Heindric Events were probably much bigger ice discharges as the top ice has less dirt.

As melt water almost always accummulates in base of the ice sheet, it is no longer sitting anchored on the uneven potholes, but floats in water above the bedrock - much like ice shelf floats over seabed.

In this respect the ice sheet is no different to the ice shelves and can rapidly collapse as rotten ice cannot hold onto the bedrocks. As a result a sudden collapse emerges and the next Heindrich Event results in rapid cooling (Dryas) as the North Atlantic basin fills with ice debris.

There are several prospective regions where Greenland Ice Sheet behaves as if it were an ice shelf, namely Melville Bay coastal anomaly, the wide outlets of North East Greenland and Petermann Fjord in North. In south Ilulissat Ice Fjord is one of concern.

Collapse of one ice shelf or ice sheet leads to domino effect, as the tongue of water from rising sea level wedges and bends ice shelves upwards, creating faults and leading to bipolar Heindrich Event with ice berg armadas emerging fairly soon on both poles. Thus any destabilisation will have knock on effects on all water margin glaciers.

AbbottisGone

Colorado Bob, how big a voice is this Kevin Anderson in the debate?

My question comes from the point of view that governments are not individually refocusing their efforts toward a 1.5 degree target and the only reason I can think of is that it would induce panic as the talk is all about how that target is I achievable.

What do you say?

AbbottisGone

( '...how that target is unachievable.' )

Bill Fothergill

@ Veli,

In no way do I dispute your description of how melting in Greenland may progress. However, if I may make some observations...

As you say, Greenland has a distinct pair of domes. However, my understanding of its topology is that much of the inland region is already pretty close to sea level. Over the couple of million years of the Pleistocene, much of Greenland has undergone isostatic adjustment, as the mass of the overlying ice gradually depresses the crustal region down towards the outer mantle.

As a consequence, much (most?) of the island is fringed by coastal ranges, which are in turn cut in many places by drainage channels created by glacier erosion.

In your comment, you mention the Younger Dryas event. As I understand things, during the retreat and eventual demise of the Laurentide Ice Sheet, a variety of massive glacial lakes were left behind on the North American continent. Probably the best known of these was Lake Agassiz, and it was the catastrophic failure of the ice dam around this body of cold freshwater that led to the YD event.

However, I think that the coastal mountain ranges around Greenland should prevent the repetition of a YD-style event. (Although a more gradual release of cold freshwater could certainly be possible.)

Moving to Antarctica, this continent is fringed by massive ice shelves which extend way beyond the coastline, and extend many, many kilometres out to sea. In this case, it is the topology of the sea bed that gives cause for alarm.

As the Antarctic Ice Shelves reach out into open waters, there are many places at which the base of the shelf is grounded against the sea bed. If the shape of the sea floor was such that it sloped gradually upwards back towards the coast, there would not be such a reason for concern.

However, in many areas, the sea bed actually falls away. With this kind of topology, there is a very real concern that the grounding line can be cut away from both sides. The result would be that the ice shelf would no longer be grounded near its periphery and would become a genuinely floating ice shelf.

The consequences of this can be seen by studying the history of church building prior to about 900 years ago. The science of mechanics was little understood - especially in terms of transfer of forces, and the lateral force generated by the weight of church roofs regularly resulted in the spectacular failure of the outer walls. This could indeed be responsible for that old refrain "... and the walls came tumbling down".

The introduction of flying buttresses into church design around the 12th Century greatly alleviated this problem.

In Antarctica, its is the grounding of the ice shelves which provides the equivalent support created by flying buttresses. If the grounding is taken away, we are going to se some interesting discharges into the Southern Ocean.

Neven

According to JAXA data, current SIE is still 69K below the preliminary peak reached last week. We had the same situation last year when a second peak almost topped the previous one towards the end of the month (just a 11K difference), after which SIE went down never to go up again. Until September, that is. ;-)

As for CT SIA, it's still 81K below the preliminary peak reached almost 2 weeks ago (!). Wipneus may look into his crystal ball and tell us if it'll get closer in coming days or not.

Wipneus

Neven,

These are my calculated values (from latest NSIDC sea ice concentration) of SIA -calculated CT style - for the next two days:

Tue 2016.1425 -42.9 12.560691
Wed 2016.1452 -113.5 12.447238

Neven

Thanks, Wipneus, you're the best. This means that CT SIA is going to be 237K below the preliminary peak. A massive change in weather conditions is needed to prevent the new record to be record early. But I'm not seeing that change in the forecast, and it looks almost 100% certain that there will be a new record anyhow, record early or not. Because it's currently 697K below the 2011 record maximum.

Where's the cold going to come from to prevent a new record?

AbbottisGone

.. are there any known problems with the sattelites?

Wipneus

None that I know of AiG, the sea ice concentration maps look entirely reasonable and independ measurements (AMSR2) show similar day-to-day swings.

John Christensen

Where's the cold going to come from to prevent a new record?


It seems the necessary ingredients would be these:
1. AO to turn negative (which is actually forecasted)
2. A high needs to position itself just north of Greenland to pull cold out of the CAA and push towards Barents
3. A weak low in south Barents to pull cold out across Kara and into Barents
4. A high in south-west Okhotsk to pull cold out across Okhotsk Sea
5. Some miracle to get Bering cold as well..

Not that hard, right? ;-)

John Christensen

And evidently, the persistent high near the Laptev and ESS coast needs to go away, maybe down to western Okhotsk..

Sarat

Sooo, is it time to call Mad Max II: The Arctic Warrior?

Neven

Taras, I have prepared a blog post with a slightly different title. :-)

I want to wait what JAXA SIE does in the next day or two before speculating.

wayne

I am not surprised, we almost had or are having the 5th major heat incursion over the Arctic Ocean's freezing season.

I have never seen so many massive heat surges during the long night. But of course its relative, if the Arctic warms by 15 C, it still has another 20 C before it reaches a mean of 0.

As for the minima, It is a matter of studying how dynamical weather will react to this when the sun is a bit higher in the sky.

AbbottisGone

1. What causes these heat incursions?

2. Where/how do we witness these heat incusions?

3. You referred to them as 'major' heat incursions: why?

Cheers!

Neven
I want to wait what JAXA SIE does in the next day or two before speculating.

Well, JAXA SIE shot up by a massive 150K and thus has exceeded the preliminary peak of 13.667 million km2 reached last week. It's still lowest in the 2007-2016 period, but now 'only' 162K below last year's record maximum.

I wonder what caused the 150K uptick and whether there's more where that came from. What's also possible, is that we see a couple of days with heavy reductions as a reaction to the large uptick.

Kris

Neven asked:

I wonder what caused the 150K uptick.

The 'uptick' is quasi enterely due to the gain in the Sea of Ochotsk. Meaning the Central Arctic and it's surrounding remain in as bad a state as before yesterday. Open water is even reaching Vize Island in the Barentz-Kara zone. Go figure ...

wayne

AbbitisGone

> 1. What causes these heat incursions?

We've been talking about AGW for years now...


2. Where/how do we witness these heat incusions?

Check out the Density Weighted Temperature of the entire troposphere. The best way to do so is to study 600 mb maps.
Where the temperature at that altitude is close to the DWT.

3. You referred to them as 'major' heat incursions: why?

The entire structure of winter extent collapsed when its suppose to be strongest. These collapses cause individualized "Polar Vortex" which cause some serious weather at times.

Surface temperatures also reflect this, but not as well.

Cheers 2!

wayne

> 1. What causes these heat incursions?

The planet is warmer and the very structure of the the coldest atmosphere during winter is morphing to unfamiliar geographical construct. This year's incursions are mainly from the North Pacific and Atlantic. Ocean in origin warm cyclones easily penetrate the Arctic when individualized Polar vortex spins Southwards, rather than the single Polar Vortex of old being more like one unified expanse. The difference makes the jet stream behave strangely as well, shooting Northwards warmer air, and Southwards colder than average air at smaller localized regions whose inhabitants often wonder what happened to GW... Or for us Northerners not amused by people who believe that there is no such thing at GW. Especially when freezing drizzle occurs in the middle of January at 75 N latitude.

Jim Hunt

Wayne asked about water temperatures. Here's the temperature under IMB buoy 2015F:

Click the image for a larger version. Is that the sort of thing you had in mind? Or temp versus depth from an ITP?

wayne

Hi Jim,


That is interesting , temperatures are remarkably steady after 1/15/16, but I am looking for diurnal data, I rather also see what happens during a 24 hours day.

But thanks mate... This is the stuff we like...

Jim Hunt

Before I put in too much extra effort at this end please take a look at the vertical resolution. Is 0.06/7 sufficient for your requirements?

Neven

Kris wrote in another comment section:

Neven wrote JAXA didn't report today. Neither did NSIDC (for what is the day before yesterday now). Likely rather some communication problem. Meanwhile, for that day before yesterday [25th], JAXA registered 13,88 millions km2 (a big uptick), and for yesterday [26th] 13,86 km2, a small 'downtick'.
.

Indeed, one more big uptick in the next 2-3 days and last year's record remains standing, as JAXA SIE is currently just 75K below it.

This max may end up just as mad as last year's, but no madder. It's a recovery. ;-)

CT SIA is a different story.

Neven

JAXA reports an increase of 30K, which means that last year's record lowest maximum has been exceeded by 447 km2!

P-maker

Leo is somehow also an "exceptional exception" - please enjoy:

https://www.youtube.com/watch?v=Dev52k5uzdc

Have a nice day

Jim Hunt

A "statistical tie" perhaps, pending tomorrow's numbers?

Other things are most certainly not equal with last year though. See for example Andrew Slater's concentration comparison:

http://GreatWhiteCon.info/resources/arctic-sea-ice-graphs/#SlaterConc

Jim Hunt

JAXA extent is falling again, leaving the current 2016 maximum in the "statistical tie" with 2015 at 13.94 million km².

Meanwhile the latest edition of Arctic Sea Ice News is out:

http://GreatWhiteCon.info/2016/02/the-2016-arctic-winter-sea-ice-puzzle/#comment-213732

Persistent warmth has continued into February; air temperatures at the 925 hPa level were 6 to 8 degrees Celsius (11 to 14 degrees Fahrenheit) above the 1981 to 2010 average over the central Arctic Ocean near the pole.

Arctic sea ice was at a satellite-record low for the second month in a row.

Bill Fothergill

" ... Persistent warmth has continued into February... "

You can say that again Jim!

RSS released their February data two days ago. After having posted the second highest global TLT in their dataset for October, this was followed by monthly global TLT records in November, December and January.

The their February figure went that little bit further, and was the highest global TLT that they had recorded in any month.

Gulp!

viddaloo

OK, so this year it seems Ms Neven was off by a whopping 19–50 days, with her "just a month or two to go before the melting season gets going" wild prediction. Does anyone know or remember how she fared last year? If my memory serves me well, she was so wrong and thus so angry, last year, that certain people who got it right had to be expelled in April from her authoritarian "sea ice" forum (which as it happens is not so much about sea ice, but social control).

I can see a nice meal of crow being prepared for her in the near future.

Now, back to the ice.

Neven

Thanks for reminding us what a loveable guy you are, vid. :-)

You were expelled from the forum because you're such a great and tolerant person [/sarc off], not because you were right and others were wrong (even if it were the case).

And I love to eat crow, because that means the winged thugs aren't harassing the other birds around my house. ;-)

Rob Dekker

Neven,
I don't know what conspired at the Forum with this guy "viddaloo", but when somebody speaks to you like he just did, why don't you just block this guy from the Arctic Sea Ice Blog altogether ?

I mean, I'm looking through his comments, it is not as he has anything substantial to say. Just condescending comments as far as I can see.
I may be mistakes, so here is one chance for Viddaloo to correct by opinion that he should be blocked outright :

Viddaloo, question for you : Which comment of yours on this fine blog do you recognize as the best comment you made ?

Neven
I don't know what conspired at the Forum with this guy "viddaloo", but when somebody speaks to you like he just did, why don't you just block this guy from the Arctic Sea Ice Blog altogether ?

It all depends on my mood. I only ban people when I'm in a good mood. ;-)

I thought I'd let this one stand, as it immediately shows what kind of person viddaloo is, in case anyone was doubting.

But of course, I won't let things go on indefinitely (it went on too long on the forum already). It would be best if vid started his own blog or forum. He can post the link here if he wants.

navegante

The thing with Viddaloo goes from comical to a bit spooky when he/she dares to "reveal" your "supposed" gender Neven (it may be true or false what Vid says, which I do not care about it). Like he/she wants to be intimidating by saying "I know more about your real you than you would like to". This is too invasive, you should ban this loon. IMHO.

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